Aramco QM7-Valve Inspection-Questions & Answers

My Reading on QM07

Valve Inspection-Reading V Questions & Answers Time

Valve Inspections & Testing For Aramco Examination 31st October 2016 ♥

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Pipeline Valves

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Pipeline Valves

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Refinery Valves

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Refinery Valves

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Pipeline Valves

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Pipeline Valves

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SME- Subject Matter Expert 我们的大学,其实应该聘请这些能干的退休教授. http://cn.bing.com/videos/search?q=Walter+Lewin&FORM=HDRSC3 https://www.youtube.com/channel/UCiEHVhv0SBMpP75JbzJShqw

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http://www.yumpu.com/zh/browse/user/charliechong http://issuu.com/charlieccchong http://www.authorstream.com/charliechong/ http://pan.baidu.com/s/1pLAgPHx

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http://greekhouseoffonts.com/

There are Magic in every Reading…

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Fion Zhang at EKERÖ 9th October 2016

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数字签名者：Fion Zhang DN：cn=Fion Zhang, o=Technical, ou=Academic, email=fion_zhang @qq.com, c=CN 日期：2016.11.01 18:14:02 +08'00' Charlie Chong/ Fion Zhang

闭门练功

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闭门练功

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闭门练功

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Adobe Acrobat Reader Hotkeys http://allhotkeys.com/adobe_acrobat_reader_hotkeys.html Ctrl + G = find again Ctrl + L = full screen Ctrl + M = zoom to Ctrl + N = go to page (insert number in box) Ctrl + Q = quit program Ctrl + + = zoom in Ctrl + - = zoom out Ctrl + 0 = fit in window Ctrl + 1 = actual size Ctrl + 2 = fit width Ctrl + 3 = fit visible Ctrl + 4 = reflow Ctrl + Shift + A = deselect all Ctrl + Shift + F = search query Ctrl + Shift + G = search results Ctrl + Shift + J = cascade windows Ctrl + Shift + K = tile windows horizontally Ctrl + Shift + L = tile windows vertically

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Ctrl + Shift + S = save a copy Ctrl + Shift + P = page setup Ctrl + Shift + W = search word assistant Ctrl + Shift + X = search select indexes Ctrl + Shift + Page Up = first page Ctrl + Shift + Page Down = last page Ctrl + Shift + + = rotate clockwise Ctrl + Shift + - = rotate counterclockwise Ctrl + Alt + W = close all Alt + Left Arrow = go to previous view Alt + Right Arrow = go to next view Alt + Shift + Left Arrow = go to previous document Alt + Shift + Right Arrow = go to next document F4 = thumbnails F5 = bookmarks F8 = hide toolbars F9 = hide menu bar http://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts http://help.adobe.com/en_US/acrobat/using/WS58a04a822e3e50102bd615109794195ff-7aed.w.html

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All about Oils

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All about Oils

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o c m a r A

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IA Procedure for GIS Inspection Services INSPECTOR QUALIFICATION AAQMD-IA-GIS-02 Commodity

Valves, Fittings and Flanges

Qualification/ Certification

Alternative Qualification/

Requirements

Certification Requirements

Mechanical General, Coating (noncritical), Nondestructive Testing (2.2.2) and pass Aramco commodity written exam (Closed Book)

co m a m r a A x E Charlie Chong/ Fion Zhang

C) Table (3) Qualification Pre-requisites

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Pre-Reading Exercise Name The Symbols

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The Questions; • • • • • • • • • •

What position is the gate in during the backseat test? At what pressure is the low pressure test done? What parts of a valve trim item? Describe the three type wedge of gate valve? A welder qualified in the 5G position may weld in what positions according to ASME IX? What type of SS filler material is commonly used to join 304 SS to carbon steel or as the first layer when overlaying CS with SS？ What’s purpose use of the screen of RT? What is NACE MR0175? Which group for material of A516 Gr.70 is classed as per ASMEIX? How to get the hydrostatic test pressure for valve easily?

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The Questions; 11. 12. 13. 14. 15.

Which paragraph of ASME VIII-1 is described the hydrostatic pressure? A vessel’s test pressure is 1000psi, which range of pressure gage will be used for hydrostatic testing? What is meant by the term "Essential Variables" in the WPS? Surface defects are more clearly defined by A.C. or D.C. current? What is meant by "film density" and how is it measured?

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Q1. What position is the gate in during the backseat test? Initial Attempt. During back seat test, the position of the gate of gate valve is half open; thus allowing the cavity to be filled with the fluids and exert outward pressure against the back seat. Should there be any leakage, the fluid will penetrate upward thru the gland. During the back seat test the gland follower is loosen to detect back seat leakage. Similarly the obturator for other valve, if there is back seat feature should also be tested with the obturator half open (half close) Comment: Wrong answer! Standard answer: (API 598 Reference)

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Standard answer: (API 598 Reference) 4.2 BACKSEAT TEST 4.2.1 The backseat test is required for all valves, except for bellows seal valves, that have the backseat feature and shall be performed by applying pressure inside the assembled valve with the valve ends closed, the valve fully open, and the packing gland loose or packing not installed. If the backseattest is performed after the shell test, the packing shall be installed and/or packing glands re-tightened after the backseat test. The successful completion of the backseat test shall not be construed as a recommendation by the valve manufacturer that, while the valve is pressurized, the valve stuffing box may be repacked or the packing may be replaced. 4.2.2 For valves 4 in. NPS and smaller, the backseat test may be combined with the shell test when volumetric devices are used to monitor leakage from the shell and backseat. When tested by this method, the packing shall be loose. The manufacturer shall be responsible for demonstrating that the packing will not leak at the valve’s rated pressure at 100°F (38°C).

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Standard answer: (API 598 Reference) 4.2 BACKSEAT TEST 4.2.1 The backseat test is required for all valves, except for bellows seal valves, that have the backseat feature and shall be performed by applying pressure inside the assembled valve with the valve ends closed, the valve fully open, and the packing gland loose or packing not installed. If the backseattest is performed after the shell test, the packing shall be installed and/or packing glands re-tightened after the backseat test. The successful completion of the backseat test shall not be construed as a recommendation by the valve manufacturer that, while the valve is pressurized, the valve stuffing box may be repacked or the packing may be replaced. 4.2.2 For valves 4 in. NPS and smaller, the backseat test may be combined with the shell test when volumetric devices are used to monitor leakage from the shell and backseat. When tested by this method, the packing shall be loose. The manufacturer shall be responsible for demonstrating that the packing will not leak at the valve’s rated pressure at 100°F (38°C).

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2nd Attempt : During back seat test, the position of the gate of gate valve is fully open and the valve ends closed with the packing gland loose or not installed; thus allowing the cavity to be filled with the fluids and exert outward pressure against the back seat. Should there be any leakage, the fluid will penetrate upward thru the gland. During the back seat test the gland follower is loosen or removed to detect back seat leakage. Keywords: Packing gland loose, gate fully open, no leakage from the gland.

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3rd Attempt: During back seat test, the position of the gate of gate valve is fully open and the valve ends closed with the packing gland loose or not installed; thus allowing the cavity to be filled with the fluids and exert outward pressure against the back seat. Should there be any leakage, the fluid will penetrate upward thru the gland. During the back seat test the gland follower is removed to detect back seat leakage. For valve 4” and smaller the test could be performed together with the high pressure shell test, if volumetric device is used for detection of leakage. Keywords: Packing gland loose, gate fully open, no leakage from the gland.

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Q2. At what pressure is the low pressure test done? Initial Attempt. The low pressure seat test is generally required for floating ball valve and optional for other valve. The test pressure is between 4~7 bars (Varies as specified in API6D, Type1 & Type 2 test). The allowable leakage rate is “0” for valve with resilient seat and as leakage rates as allowed for metal seat in API598. (Other allowable leakage rate are also specified as in API6D. Low pressure gas seat testing in API6D specified; rate “A” for soft seated and lubricated valves and rate “D” for metal seat valves in accordance with ISO5208.) Comment:

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Standard answer: (API 598 Reference) 4.4 LOW-PRESSURE CLOSURE TEST 4.4.1 The low-pressure closure test shall be performed with the seat sealing surface interface clean and free from oil, grease, and sealant. If necessary to prevent galling, the sealing surfaces may be coated with a film of oil that is not heavier than kerosene. This requirement does not apply to a valve that uses a lubricant as its primary seal (e.g., lubricated plug valves). 4.4.2 Any leakage at the seat sealing surface interface, behind the seat ring, or through the disk on the open side of the valve shall be detected when bubbles are observed coming from the closure (disk, seat, and seat ring), which is either covered with water or coated with a soap or similar solution. As an alternative, displacement measuring devices may be used, provided that the detectable leakage rate is equivalent to that given in Table 5, the valve manufacturer can demonstrate and validate that the procedure yields results equivalent to the requirements of this standard, and the device has been accepted by agreement between the purchaser and the manufacturer. Bubbler testing, when used for valves larger than NPS 2, shall only be acceptable when agreed to by the purchaser. Charlie Chong/ Fion Zhang

Table 5—Maximum Allowable Leakage Rates for Closure Tests

the valve manufacturer can demonstrate and validate that the procedure yields results equivalent to the requirements of this standard, and the device has been accepted by agreement between the purchaser and the manufacturer. Bubbler testing, when used for valves larger than NPS 2, shall only be acceptable when agreed to by the purchaser.

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When volumetric devices (bubblers) are used to measure leakage, the test duration shall not begin until flow through the test tubing is established and stabilized. The device shall be calibrated to yield results equivalent to the units per minute listed in Table 5. Volumetric devices shall be calibrated with the same test fluid and at the same temperature as used for the production tests. 4.4.3 When closure testing gate, plug, and ball valves, the valve manufacturer shall use a method of testing seat leakage that fills and fully pressurizes the body cavity to the test pressure between the seats and the bonnet area, as applicable, with the test fluid. This will ensure that no seat leakage can escape detection because of gradual filling of these volumes during the test period. For a valve (other than a double block-and-bleed valve or globe valve) designed to close against pressure from either direction, the pressure shall be applied successively to each side of the closed valve with the other side open to the atmosphere to check for leakage at the atmospheric side of the closure. For a globe valve, pressure shall be applied in one direction with the pressure applied under the disk.

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For a valve designed to close against pressure from one direction only and so marked, the pressure shall be applied on the pressure side of the valve only. For a check valve, the pressure shall be applied on the downstream side. For a double block-and-bleed valve, the pressure shall be applied successively to each side of the closure through the valve port. Leakage into the body cavity between the seats shall be checked through observation at a tapped opening between the seats. Valves shall be tested with the stem in the vertical upright position. Leakage from the seats shall not exceed rates shown in Table 5. A closure test is required only in one direction for butterfly valves furnished with encapsulation or resilient internal liners and designed for use with Class 125 or Class 150 flanges (API Std 609 Category A valves). For other resilientseated butterfly valves (API Std 609 Category B valves), the closure test is required in both directions. For valves with a preferred flow direction, the closure test in the non-preferred direction shall be based on the reduced differential pressure rating in that direction.

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4.4.4 Trapping test air or gas in the body cavity between the seats of a onepiece (solid or flexible) wedge gate valve and subsequently covering the seats with water or coating them with soap or a similar solution does not constitute an acceptable low-pressure closure test. 4.4.5 If a tapped connection in the body cavity is made to permit testing procedures described under double block-and- bleed valve in 4.4.3, the connection shall be in accordance with MSS SP-45 and shall be fitted before shipment with a solid pipe plug (in accordance with ANSI B16.11) whose material composition is equivalent to that of the valve shell.

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Supplementary Information: (API598-2004)

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Supplementary Information: (API598-2004)

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Standard answer: (API6D) ANNEX H (normative) Supplementary Test Requirements H.1 General This annex specifies requirements for supplementary testing, which shall be performed by the manufacturer if specified by the purchaser. The frequency of testing shall also be specified by the purchaser, if not defined in this annex. H.2 Hydrostatic Testing By agreement, hydrostatic testing may be performed at pressures higher than specified in 9.3 and 9.4 and/or for periods longer than specified in Table 4, Table 5, and Table 6.

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H.3 Low-pressure Gas Seat Testing H.3.1 General The valve shall be drained of hydrostatic test fluid prior to the start of the low pressure gas seat test. H.3.2 Type I The seat test specified in 9.4 shall be repeated at a test pressure between 5 psi and 14.5 psi (0.34 barg and 1 bar) using air or nitrogen as the test medium. H.3.3 Type II The seat test specified in 9.4 shall be repeated at a test pressure between 80 psi and 100 psi (5.5 bar and 6.9 bar) using air or nitrogen as the test medium. H.3.4 Acceptance The acceptable leakage rate for low-pressure gas seat testing shall be: ISO 5208, Rate A (no visible leakage), for soft-seated valves and lubricated plug valves; ISO 5208, Rate D, for metal-seated valves.

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ISO 5208

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Q3. What parts of a valve trim item? Initial Attempt. Valve's trim is a collective name for the replaceable parts, in a valve. A typically Trim design includes a (1) disk, (2) seat, (3) stem, (4) seal and (5) sleeves needed to guide the stem. Comment:

Standard answer: (API6DReference)

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Standard answer: (API6D-2014)

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Q4. Describe the three type wedge of gate valve. Initial Attempt. The 3 type of wedges for gate valves are: ■ The one piece solid wedge ■ The one piece flexible wedge (with waffle center) ■ The two piece split wedges/ parallel seats (at an angle) Both the one piece flexible and two pieces split wedges have spreading mechanism that forces the discs to the body seats when (forced) closed. The split wedge gate consists of two independent seating parts, on closing the differential movement between the two seats (contacting faces slightly at an angle with each other), force the wedges to conform to the body seats (with resulting outward force) when closed providing excellent sealing. Comment:

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Standard answer: (API Standard 600, Eleventh Edition October 2001/ISO10434: 1998 ANSI/API Std 600-2001) 5.6 Gate 5.6.1 Gate configurations are categorized as illustrated in Annex B. 5.6.1.1 A one-piece wedge gate, as either a solid or flexible wedge design, shall be furnished unless otherwise specified. 5.6.1.2 A two-piece split wedge gate or parallel seat double disc gate may be furnished when specified. A split wedge gate consists of two independent seating parts that conform to the body seats when closed. A double disc gate has a spreading mechanism that forces the two parallel discs to the body seats when closed.

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Q5. A welder qualified in the 5G position may weld in what positions according to ASME IX? Initial Attempt. A welder qualified in 5G position as per ASME IX may welds: Pipe in horizontal position Pipe & plate in 1G flat positions Pipe & plate in 2G horizontal positions Pipe & plate in 3G vertical up/down positions Pipe & plate in 4G overhead positions The qualification does not allow welding of pipe in 6G inclined position. Comment:

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Standard answer: (API 598 Reference) 2010 SECTION IX QW-405 Positions QW-405.1 The addition of other welding positions than those already qualified. See QW-120, QW-130, QW-203, and QW-303. QW-303 Limits of Qualified Positions and Diameters (See QW-461) QW-303.1 Groove Welds — General. Welders and welding operators who pass the required tests for groove welds in the test positions of table QW461.9 shall be qualified for the positions of groove welds and fillet welds shown in table QW-461.9. In addition, welders and weldingoperators who pass the required tests for groove welds shall also be qualified to make fillet welds in all thicknesses and pipe diameters of any size within the limits of the welding variables of QW-350 or QW-360, as applicable.

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NOTES: (1) Positions of welding as shown in QW-461.1 and QW-461.2. F = Flat H = Horizontal V = Vertical O = Overhead (2) Pipe 27⁄8 in. (73 mm) O.D. and over. (3) See diameter restrictions in QW-452.3, QW-452.4, and QW-452.6.

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2nd Attempt: A welder qualified in 5G position as per ASME IX may welds: Pipe & plate in 1G flat positions Pipe & plate in 3G vertical up/down positions Pipe & plate in 4G overhead positions The qualification does not allow welding of pipe in 2G plate & pipe in horizontal position and 6G pipe inclined position. Comment:

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Q6. What type of SS filler material is commonly used to join 304 SS to carbon steel or as the first layer when overlaying CS with SS？ Initial Attempt. To joint 304SS to carbon steel or performing overlaying of stainless steel on carbon steel, the initial or first weld layer is usually performed with SS309. SS309 electrode is chosen due to it high Chromium & Nickel contents. These higher alloys content counter act the effect of Fe dilution from the base metal (contributed from the fusion layer), ensuring the initial layer having reasonably high Cr/Ni contents. Comment:

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Standard answer: (Nickel Development Institute) Filler-metal considerations. One of the most common DMW combinations is type 304 (UNS S30400) stainless to a low-carbon or mild steel. Type 308 (S30800), the standard filler metal for welding type 304 to itself, should not be used to make this weld. Some type 308 welds may be satisfactory, but eventually there will be quality problems because of iron dilution. A higher alloy filler metal such as type 309 (S30900) with a ferrite number (FN) over 10 or type 312 (S31200) with an FN over 25 should be used. The effect of dilution on an austenitic stainless steel weld can be illustrated using the WRC 1988 diagram in Figure 2. The structure of a stainless steel weld may be fully austenitic, such as type 310 (S31000), or contain varying amounts of delta ferrite, as with types 308, 309 or 312. The amount of ferrite is determined by the composition and weld cooling rates; the faster the cooling, the higher the ferrite content. Fully austenitic welds are more susceptible to hot cracking or fissures than welds containing about 5% or more ferrite.

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https://nickelinstitute.org/~/Media/Files/TechnicalLiterature/GuidelinesforWeldingDissimilarMetals_14018_.pdf

2nd Attempt: To joint 304SS to carbon steel or performing overlaying of stainless steel on carbon steel, DMW (dissimilar metal weld) the initial or first weld layer is usually performed with SS309 with FN >10 or SS312 with FN >25. SS309/SS312 electrode is chosen due to it high Chromium & Nickel contents. These higher alloys content counter act the effect of Fe dilution from the base metal (contributed from the fusion layer), ensuring the initial layer having reasonably high Cr/Ni contents. For welding of stainless steel, FN>5 is generally required to prevent hot cracking Comment:

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Q7. What’s purpose use of the screen of RT? Initial Attempt. There are 2 type of screens, group by locations. The front and the back screen. The purposes of screen in radiographic testing are: For both, intensifying the radiation source by electron emission thus reducing the exposure time. For front screen, filter out the low energy radiations which usually are front scattered radiation thus resulting in sharper images For back screen, filter out the low energy radiations which usually are back scattered radiation thus resulting in sharper images Comment:

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Standard answer: (nde-ed.0rg) Lead Foil Screens Lead foil screens are often used to enhance the radiograph when using Xrays in the range of 150 to 400 kV. The screens increase the exposure of the film largely due to electrons emitted by the screens during an exposure. The following are a few experiments that can be performed to investigate the effects of lead foil screens. https://www.nde-ed.org/TeachingResources/NDT_Tips/X-rayScreens.htm

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Standard answer: (nde-ed.0rg) Secondary (Scatter) Radiation and Undercut Control Secondary or scatter radiation must often be taken into consideration when producing a radiograph. The scattered photons create a loss of contrast and definition. Often secondary radiation is thought of as radiation striking the film reflected from an object in the immediate area, such as a wall, or from the table or floor where the part is resting. Side scatter originates from walls, or objects on the source side of the film. Control of side scatter can be achieved by moving objects in the room away from the film, moving the x-ray tube to the center of the vault, or placing a collimator at the exit port, thus reducing the diverging radiation surrounding the central beam. It is often called backscatter when it comes from objects behind the film. Industry codes and standards often require that a lead letter "B" be placed on the back of the cassette to verify the control of backscatter. If the letter "B" shows as a "ghost" image on the film, a significant amount of backscatter radiation is reaching the film. The image of the "B" is often very nondistinct as shown in the image to the right. The arrow points to the area of backscatter radiation from the lead "B" located on the back side of the film. The control of backscatter radiation is achieved by backing the film in the cassette with a sheet of lead that is at least 0.010 inch thick. It is a common practice in industry to place a 0.005" lead screen in front and a 0.010" screen behind the film. https://www.nde-ed.org/EducationResources/CommunityCollege/Radiography/Physics/scatterradcontrol.htm

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Q8. What is NACE MR0175? Initial Attempt. NACE MR0175, is a NACE material requirement standard for material exposing to H2S in oil & gas production. Broadly, the standard specified requirements for limiting the material hardness base of material grouping, UTS, PH and H2S partial pressure, to avoid material deterioration (cracking) due to the effects on H2S exposure in oil & gas production. Comment:

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Standard answer: (API 598 Reference)

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1 Scope This part of ANSI/NACE MR0175/ISO 15156 gives requirements and recommendations for the selection and qualification of carbon and low-alloy steels for service in equipment used in oil and natural gas production and natural gas treatment plants in H2S-containing environments, whose failure can pose a risk to the health and safety of the public and personnel or to the environment. It can be applied to help to avoid costly corrosion damage to the equipment itself. It supplements, but does not replace, the materials requirements of the appropriate design codes, standards or regulations. This part of ANSI/NACE MR0175/ISO 15156 addresses the resistance of these steels to damage that can be caused by sulfide stress cracking (SSC) and the related phenomena of stress-oriented hydrogen-induced cracking (SOHIC) and soft-zone cracking (SZC). This part of ANSI/NACE MR0175/ISO 15156 also addresses the resistance of these steels to hydrogeninduced cracking (HIC) and its possible development into stepwise cracking (SWC). This part of ANSI/NACE MR0175/ISO 15156 is concerned only with cracking. Loss of material by general (mass loss) or localized corrosion is not addressed. Table 1 provides a non-exhaustive list of equipment to which this part of ANSI/NACE MR0175/ISO 15156 is applicable, including permitted exclusions. This part of ANSI/NACE MR0175/ISO 15156 applies to the qualification and selection of materials for equipment designed and constructed using conventional elastic design criteria. For designs utilizing plastic criteria (e.g. strain-based and limit-state designs), see ANSI/NACE MR0175/ISO 15156- :2009, Clause 5. Annex A lists SSC-resistant carbon and low alloy steels, and A.2.4 includes requirements for the use of cast irons. This part of ANSI/NACE MR0175/ISO 15156 is not necessarily suitable for application to equipment used in refining or downstream processes and equipment. Charlie Chong/ Fion Zhang

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Q9. Which group for material of A516 Gr.70 is classed as per ASMEIX? Initial Attempt. A516 Gr.70 is carbon-manganese steel fall under group 1 in ASME IX Comment:

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Standard answer: (ASME IX)

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Standard answer: (ASME IX)

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Standard answer: (ASME IX)

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2nd Attempt: A516 Gr.70 is carbon-manganese-silicon (C-Mn-Si) steel fall under P1 group 2 in ASME IX Comment:

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Q10. How to get the hydrostatic test pressure for valve easily? Initial Attempt. There is no easy way of getting the hydrostatic test pressure. The hydrostatic testing of valves must be performed as per specification requirements, code (API600, API6D, API598, ASTM B16.34 etc.). The test pressure shall be required for the valve class temperature-pressure and the test duration specified in the referred document. The test instruments shall be calibrated and within the period of validities. Comment:

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Standard answer: (ASTM 16.34 Reference) 7 PRESSURE TESTING 7.1 Shell Test 7.1.1 Shell Test Pressure. Each valve shall be given a shell test at a gage pressure no less than 1.5 times the 38°C (100°F) pressure rating, rounded off to the next higher 1 bar (25 psi) increment. The test shall be made with water, which may contain a corrosion inhibitor, with kerosene, or with other suitable fluid,3 provided such fluid has viscosity not greater than that of water, at a temperature not above 50°C (125°F). The test shall be made with the valve in the partially open position. 7.1.2 Test Duration. The shell test duration, the test period of inspection after the valve is fully prepared and is under shell test pressure, shall be not less than the following:

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2nd Attempt: There is no easy way of getting the hydrostatic test pressure. The hydrostatic testing of valves must be performed as per specification requirements, code (API600, API6D, API598, ASTM B16.34 etc.). The test pressure shall be required for the valve class temperature-pressure and the test duration specified in the referred document. The test instruments shall be calibrated and within the period of validities. The pressures are measured by calibrated gauges, pressure transmitter. The test acceptance are based on leakage rate for seat test and no leakage or break of pressure boundary for shell test. The leakage rate could be detected by: Volumetric means, visual, bubble counting.

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Q11. Which paragraph of ASME VIII-1 is described the hydrostatic pressure? Initial Attempt. UG 99 defined the hydrostatic testing requirements for testing of pressure vessel. The paragraph specified that the test pressure at the top of the vessel shall be 1.3 times the MAWP maximum allowable working pressure, multiplied by the LSR lowest stress ration, reducing any hydrostatic head pressure on the elements. The LSR is the stress at testing temperature to the stress at design temperature Comment:

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Standard answer: (API 598 Reference) UG-99 STANDARD HYDROSTATIC TEST (a) A hydrostatic test shall be conducted on all vessels after: (1) all fabrication has been completed, except for operations which could not be performed prior to the test such as weld end preparation [see U1(e)(1)(a)], cosmetic grinding on the base material which does not affect the required thickness; and (2) all examinations have been performed, except thoserequired after the test. The completed vessels, except those tested in accordance with the requirements of UG-100 and UG-101, shall have satisfactorily passed the hydrostatic test prescribed in this paragraph.

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Standard answer: (API 598 Reference) (b) Except as otherwise permitted in (a) above and 27- 4, vessels designed for internal pressure shall be subjected to a hydrostatic test pressure that at every point in the vessel is at least equal to 1.3 times the maximum allowable working pressure34 multiplied by the lowest stress ratio (LSR) for thematerials of which the vessel is constructed. The stress ratio for each material is the stress value S at its test temperature to the stress value S at its design temperature (see UG-21). Bolting shall not be included in the determination of the LSR, except when 1.3 times the LSR multiplied by the allowable stress of the bolt at its design temperature exceeds 90% of the bolt material specified minimum yield strength at the test temperature. All loadings that may exist during this test shall be given consideration.

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Standard answer: (API 598 Reference) (c) A hydrostatic test based on a calculated pressure may be used by agreement between the user and the Manufacturer. The hydrostatic test pressure at the top of the vessel shall be the minimum of the test pressures calculated by multiplying the basis for calculated test pressure as defined in 3-2 for each pressure element by 1.3 and reducing this value by the hydrostatic head on that element. When this pressure is used, the Inspector shall reserve the right to require the Manufacturer or the designer to furnish the calculations used for determining the hydrostatic test pressure for any part of the vessel. 34The

maximum allowable working pressure may be assumed to be the same as the design pressure when calculations are not made to determine the maximum allowable working pressure.

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Q12. A vessel’s test pressure is 1000psi, which range of pressure gage will be used for hydrostatic testing? Initial Attempt. The pressure gauge for hydrostatic testing shall has a measuring range 1.5x to 4x dial reading. For test pressure of 1000psi, the gauge should be within 1500psi min~ 4000psi max. Comment:

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Standard answer: (ASME VIII) UG-102 TEST GAGES (a) An indicating gage shall be connected directly to the vessel. If the indicating gage is not readily visible to the operator controlling the pressure applied, an additional indicating gage shall be provided where it will be visible to the operator throughout the duration of the test. For large vessels, it is recommended that a recording gage be used in addition to indicating gages. (b) Dial indicating pressure gages used in testing shall be graduated over a range of about double the intended maximum test pressure, but in no case shall the range be less than 1½ nor more than 4 times that pressure. Digital reading pressure gages having a wider range of pressure may be used provided the readings give the same or greater degree of accuracy as obtained with dial pressure gages. (c) All gages shall be calibrated against a standard deadweight tester or a calibrated master gage. Gages shall be recalibrated at any time that there is reason to believe that they are in error.

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2nd Attempt: The dial pressure gauge for hydrostatic testing shall has a measuring range 1.5x to 4x dial reading. For test pressure of 1000psi, the gauge should be within 1500psi min~ 4000psi max. If digital reading gauges with wide range reading are used, they shall have the same degree of accuracy as the dial range with the range specified as above. Comment:

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Q13. What is meant by the term "Essential Variables" in the WPS? Initial Attempt. Essential variables are parameter of the welding procedure qualifications or welder qualification test that if change is make, requires requalification y retesting. Comment:

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Standard answer: (ASME IX Introduction) PROCEDURE QUALIFICATIONS Each process that has been evaluated by Section IX is listed separately with the essential and nonessential variables as they apply to that particular process. In general, the Welding Procedure Specifications (WPS) and the Brazing Procedure Specifications (BPS) are to list all essential and nonessential variables for each process that is included under that particular procedure specification. If a change is made in any essential variable, requalification of the procedure is required. If a change is made in a nonessential variable, the procedure need only be revised or amended to address the nonessential variable change. When notch toughness is required by the construction code, the supplementary essential variables become additional essential variables and a change requires requalification of the procedure.

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Q14. Surface defects are more clearly defined by A.C. or D.C. current?? Initial Attempt. When using MPI testing surface defects are more clearly shown by the A.C current methods. This is due to alternating current provides mobility in the magnetic particle (either dry or wet). The disadvantages in using Ａ.C methods is the depth of magnetic field penetration is some what reduce as compare to direct current method. Comment:

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Standard answer: (ndt-ed) Magnetizing Current As seen in the previous pages, electric current is often used to establish the magnetic field in components during magnetic particle inspection. Alternating current and direct current are the two basic types of current commonly used. Current from single phase 110 volts, to three phase 440 volts, are used when generating an electric field in a component. Current flow is often modified to provide the appropriate field within the part. The type of current used can have an effect on the inspection results, so the types of currents commonly used will be briefly reviewed. Direct Current Direct current (DC) flows continuously in one direction at a constant voltage. A battery is the most common source of direct current. As previously mentioned, current is said to flow from the positive to the negative terminal. In actuality, the electrons flow in the opposite direction. DC is very desirable when inspecting for subsurface defects because DC generates a magnetic field that penetrates deeper into the material. In ferromagnetic materials, the magnetic field produced by DC generally penetrates the entire cross-section of the component. Conversely, the field produced using alternating current is concentrated in a thin layer at the surface of the component. Alternating Current Alternating current (AC) reverses in direction at a rate of 50 or 60 cycles per second. In the United States, 60 cycle current is the commercial norm but 50 cycle current is common in many countries. Since AC is readily available in most facilities, it is convenient to make use of it for magnetic particle inspection. However, when AC is used to induce a magnetic field in ferromagnetic materials, the magnetic field will be limited to narrow region at the surface of the component. This phenomenon is known as the "skin effect" and occurs because the changing magnetic field generates eddy currents in the test object. The eddy currents produce a magnetic field that opposes the primary field, thus reducing the net magnetic flux below the surface. Therefore, it is recommended that AC be used only when the inspection is limited to surface defects. Charlie Chong/ Fion Zhang

https://www.nde-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/MagnetizingCurrent.htm

Q15. What is meant by "film density" and how is it measured? Initial Attempt. Film density, more properly addressed as “H&D film density” is a measured of degree of darkness of a radiographic film. Numerically it is expressed as: H&D Fil Density = Log (It/Io) Where: I = transmitted light intensity Io = initial light intensity Comment:

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Standard answer: (nde-ed) Radiographic Density Radiographic density (AKA optical, photographic, or film density) is a measure of the degree of film darkening. Technically it should be called "transmitted density" when associated with transparent-base film since it is a measure of the light transmitted through the film. Radiographic density is the logarithm of two measurements: the intensity of light incident on the film (Io) and the intensity of light transmitted through the film (It). This ratio is the inverse of transmittance.

D = log Io/It Similar to the decibel, using the log of the ratio allows ratios of significantly different sizes to be described using easy to work with numbers. The following table shows the relationship between the amount of transmitted light and the calculated film density

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https://www.nde-ed.org/EducationResources/CommunityCollege/Radiography/TechCalibrations/radiographicdensity.php

2nd Attempt: Film density, more properly addressed as “H&D film density” is a measured of degree of darkness of a radiographic film. Numerically it is expressed as: H&D Film Density = Log (Io/It) Where: It = transmitted light intensity Io = incident light intensity Comment:

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Q16. What is the purpose of post weld heat treatment? Initial Attempt. The purposes of PWHT could be summarized as follows; - Stress relieving especially for thick welded material to prevent cracking; - Stress relieving to prevent stress corrosion cracking; - Refine microstructures to improve notch toughness; - Reduce hardness for sour service environment; - Baked out nascent hydrogen to avoid hydrogen induced cracking Comment:

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Standard answer: (TWI- Technical Knowledge) Post Weld Heat Treatment (PWHT) So what does the term 'post weld heat treatment' mean? To some engineers it is a rather vague term that is used to describe any heat treatment that is carried out when welding is complete. To others however, particularly those working in accordance with the pressure vessel codes such as BS PD 5500, EN 13445 or ASME VIII, it has a very precise meaning. When an engineer talks of post weld heat treatment, annealing, tempering or stress relief it is therefore advisable. Heat treatment following welding may be carried out for one or more of three fundamental reasons: to achieve dimensional stability in order to maintain tolerances during machining operations or during shake-down in service to produce specific metallurgical structures in order to achieve the required mechanical properties to reduce the risk of in-service problems such as stress corrosion or brittle fracture by reducing the residual stress in the welded component The range of heat treatments to achieve one or more of these three objectives in the range of ferrous and non-ferrous metals and alloys that may be welded is obviously far too extensive to cover in great detail within these brief Job Knowledge articles. The emphasis in the following section will be on the PWHT of carbon and low alloy steels as required by the application standards although brief mention will be made of other forms of heat treatment that the welding engineer may encounter in the ferrous alloys. There are two basic mechanisms that are involved, firstly stress relief and secondly microstructural modifications or tempering.

Stress Relief Why is it necessary to perform stress relief? It is an expensive operation requiring part or all of the welded item to be heated to a high temperature and it may cause undesirable metallurgical changes in some alloys. As mentioned above there may be one or more reasons. The high residual stresses locked into a welded joint may cause deformation outside acceptable dimensions to occur when the item is machined or when it enters service. High residual stresses in carbon and low alloy steels can increase the risk of brittle fracture by providing a driving force for crack propagation. Residual stresses will cause stress corrosion cracking to occur in the correct environment eg carbon and low alloy steels in caustic service or stainless steel exposed to chlorides.

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http://www.twi-global.com/technical-knowledge/job-knowledge/heat-treatment-of-welded-joints-part-1-114/

Q17. Describe the acronym and welding process for FCAW Initial Attempt. FCAW is acronym for flux core arc welding. FCAW is an arc welding process produce weld without external pressure by arc form between the work piece and electrode with flux provided within the electrode core, supplementary inert gas shield may or may not be provided. Comment:

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Standard answer: (AWS- FCAW) Flux Cored Arc Welding: Arc Signals, Processing and Metal Transfer Characterization ABSTRACT. Metal droplet transfer in flux cored arc welding (FCAW) was studied using electrical arc signals and droplets collected from the welding process. A large number of metal droplets from the FCAW experiments was collected. According to the size distribution of the droplets, several metal transfer modes could be identified amongst which spray transfer predominated. The electrical arc signals, in particular, voltage, were processed using the fast Fourier transform (FFT) technique. Characteristic spectral frequencies corresponding to different metal transfer modes were identified. The size distribution of the collected droplets correlated extremely well with these characteristic frequencies. The electrode melt rate, calculated using the characteristic frequencies identified from the FFT analysis, agreed closely with the measured melt rate. Results from the arc signal analysis and the FFT analysis showed that both arc voltage fluctuations (Au) and characteristic frequencies of the FFT spectra were adequate to distinguish the different kinds of metal transfer modes in FCAW. Metal transfer mode maps, constructed using the two sets of results, were used to determine the optimal parameters for E71T-1, 1/16-in.-diameter electrode, and Ar-25%CO 2 shielding gas.

More reading: https://www.welding.org/product/flux-cored-arc-welding-3/

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https://app.aws.org/wj/supplement/WJ_1995_11_s369.pdf

Q18. Which position qualified can weld all position of the pipe? Initial Attempt. To weld all position of pipe, the welder need to be either qualified in 6G all position or 5G pipe horizontal plus 2 G horizontal position. Comment:

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NOTES: (1) Positions of welding as shown in QW-461.1 and QW-461.2. F = Flat H = Horizontal V = Vertical O = Overhead (2) Pipe 27⁄8 in. (73 mm) O.D. and over. (3) See diameter restrictions in QW-452.3, QW-452.4, and QW-452.6.

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Q19. For the low pressure seat test what test medium is used? Initial Attempt. For low pressure seat test the testing medium shall be water or oil (kerosene) with viscosity not exceeding that of water. Comment:

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Standard answer: (ASME B16.34) 7 PRESSURE TESTING 7.1 Shell Test 7.1.1 Shell Test Pressure. Each valve shall be given a shell test at a gage pressure no less than 1.5 times the 38°C (100°F) pressure rating, rounded offto the next higher 1 bar (25 psi) increment. The test shall be made with water, which may contain a corrosion inhibitor, with kerosene, or with other suitable fluid,3 provided such fluid has viscosity not greater than that ofwater, at a temperature not above 50°C (125°F). The test shall be made with the valve in the partially open position.

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Standard answer: (API6D-2014 Reference) H.3 Low-pressure Gas Seat Testing H.3.1 General The valve shall be drained of hydrostatic test fluid prior to the start of the low-pressure gas seat test. H.3.2 Type I The seat test specified in 9.4 shall be repeated at a test pressure between 5 psi and 14.5 psi (0.34 barg and 1 bar) using air or nitrogen as the test medium. H.3.3 Type II The seat test specified in 9.4 shall be repeated at a test pressure between 80 psi and 100 psi (5.5 bar and 6.9 bar) using air or nitrogen as the test medium. H.3.4 Acceptance The acceptable leakage rate for low-pressure gas seat testing shall be: ■ ISO 5208, Rate A (no visible leakage), for soft-seated valves and lubricated-plug valves; ■ ISO 5208, RateD, for metal-seated valves.

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Standard answer: (API598-2004 Reference) 4.4 LOW-PRESSURE CLOSURE TEST 4.4.1 The low-pressure closure test shall be performed with the seat sealing surface interface clean and free from oil, grease, and sealant. If necessary to prevent galling, the sealing surfaces may be coated with a film of oil that is not heavier than kerosene. This requirement does not apply to a valve that uses a lubricant as its primary seal (e.g., lubricated plug valves). 4.4.2 Any leakage at the seat sealing surface interface, behind the seat ring, or through the disk on the open side of the valve shall be detected when bubbles are observed coming from the closure (disk, seat, and seat ring), which is either covered with water or coated with a soap or similar solution. As an alternative, displacement measuring devices may be used, provided that the detectable leakage rate is equivalent to that given in Table 5, the valve manufacturer can demonstrate and validate that the procedure yields results equivalent to the requirements of this standard, and the device has been accepted by agreement between the purchaser and the manufacturer. Bubbler testing, when used for valves larger than NPS 2, shall only be acceptable when agreed to by the purchaser.

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Standard answer: (API598-2004 Reference) When volumetric devices (bubblers) are used to measure leakage, the test duration shall not begin until flow through the test tubing is established and stabilized. The device shall be calibrated to yield results equivalent to the units per minute listed in Table 5. Volumetric devices shall be calibrated with the same test fluid and at the same temperature as used for the production tests. 4.4.3 When closure testing gate, plug, and ball valves, the valve manufacturer shall use a method of testing seat leakage that fills and fully pressurizes the body cavity to the test pressure between the seats and the bonnet area, as applicable, with the test fluid (fluid could either be liquid or gas) . This will ensure that no seat leakage can escape detection because of gradual filling of these volumes during the test period. For a valve (other than a double block-and-bleed valve or globe valve) designed to close against pressure from either direction, the pressure shall be applied successively to each side of the closed valve with the other side open to the atmosphere to check for leakage at the atmospheric side of the closure. Charlie Chong/ Fion Zhang

Standard answer: (API598-2004 Reference) For a globe valve, pressure shall be applied in one direction with the pressure applied under the disk. For a valve designed to close against pressure from one direction only and so marked, the pressure shall be applied on the pressure side of the valve only. For a check valve, the pressure shall be applied on the downstream side. For a double block-and-bleed valve, the pressure shall be applied successively to each side of the closure through the valve port. Leakage into the body cavity between the seats shall be checked through observation at a tapped opening between the seats. Valves shall be tested with the stem in the vertical upright position. Leakage from the seats shall not exceed rates shown in Table 5. A closure test is required only in one direction for butterfly valves furnished with encapsulation or resilient internal liners and designed for use with Class 125 or Class 150 flanges (API Std 609 Category A valves). For other resilient-seated butterfly valves (API Std 609 Category B valves), the closure test is required in both directions. For valves with a preferred flow direction, the closure test in the non-preferred direction shall be based on the reduced differential pressure rating in that direction.

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Standard answer: (API598-2004 Reference) 4.4.4 Trapping test air or gas in the body cavity between the seats of a onepiece (solid or flexible) wedge gate valve and subsequently covering the seats with water or coating them with soap or a similar solution does not constitute an acceptable low-pressure closure test. 4.4.5 If a tapped connection in the body cavity is made to permit testing procedures described under double blockand- bleed valve in 4.4.3, the connection shall be in accordance with MSS SP-45 and shall be fitted before shipment with a solid pipe plug (in accordance with ANSI B16.11) whose material composition is equivalent to that of the valve shell.

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Standard answer: (API598-2004 Reference) 4.5 HIGH-PRESSURE CLOSURE TEST 4.5.1 The procedure for the high-pressure closure test shall be the same as the procedure for the low-pressure closure test except that, in the case of a liquid test, leakage shall be detected when drops, not bubbles as described in 4.4 are observed.

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2nd Attempt: For low pressure seat test the testing medium shall be either air or water with corrosion inhibitor or fluid (e.g. kerosene) with viscosity not exceeding that of water at 50ºC, usually gas. If the test is a low pressure gas seat test (API6D, low pressure gas seat test) the testing medium shall either be air or nitrogen. Comment:

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3rd Attempt: For low pressure seat test the testing medium shall be air or nitrogen. (If the test is a low pressure gas seat test (API6D, low pressure gas seat test) the testing medium shall either be air or nitrogen.) Comment:

More reading: http://paskals.com/new/COMPLETE%20CATALOG%20FOR%20VALVE%20TEST%20RIGS.pdf

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Q20. Why are shielding gases used during welding? Initial Attempt. Shielding gas or mixture of gaseous (usually Helium, Argon, O2, CO2, N2) are used in Gas Metal Arc Welding GMAW/MIG, Tungsten Inert Gas welding (TIG) and some time in FCAW Flux Core Arc Welding-Gas Shield. The primary purpose of the gas shield is to provide protection on the arc pool from the effect of O2 and N2, preventing oxidation, desired weld formation and controls of weld spatters. http://www.linde-gas.com/internet.global.lindegas.global/en/images/Overview_of_shielding_gases_60734_1217_82202.pdf

Some time, gas constituents are purposely tailored in the shielding gas to refine the weld microstructure to improve notch toughness. https://www.researchgate.net/publication/232962676_The_Influence_of_Shielding_Gas_on_Notch_Toughness_of_Stainless_Steel_Weld_Metals

Comment:

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Standard answer: (AWS Reference) Shielding Gas Oxygen Equivalent in Weld Microstructure Optimization Metal The development of an oxygen equivalent helps in the prediction of phase transformations and cracking susceptibility ABSTRACT. One of the compositional variables that strongly influence low-carbon structural steel weld metal microstructure and mechanical properties is the weld metal oxygen content. As the weld metal oxygen content varies, a change in microstructure occurs. At low concentrations of oxygen, ferrite with aligned or nonaligned second phases may become predominant, slightly higher oxygen levels may result in the formation of the desired acicular ferrite, and further increases in the oxygen content promote the formation of grain boundary ferrite. The start of austenite decomposition and ferrite nucleation are very sensitive to variations in the amount of oxygen present in the weld metal. Consequently, for a given cooling rate and chemical composition, the final weld metal microstructure can be fine-tuned by proper control of the weld metal oxygen concentration. Thus, in gas metal arc welding, adjusting the shielding gas oxygen potential provides a means of controlling the weld metal oxygen content. Bead-in-groove gas metal arc welding experiments were performed on HSLA steel coupons using three different welding wires and two heat inputs. A total of 17 different argon-based oxygen and carbon dioxide shielding gas mixtures was used. Complete metallographic and chemical analyses were carried out to evaluate the weld specimens. Sub-size M. I. ONSOIEN is with SINTEF Materials Technology, Trondheim, Norway. 5. LIU and D. L. OL50N are with the Center for Welding and Joining Research, Colorado School of Mines, Golden, Colo. Charpy V-notch toughness testing was performed on selected welds. A shielding gasrelated parameter named oxygen equivalent was developed for the discussion of the effects of the shielding gas composition on weld metal chemical composition, microstructure and toughness. The results showed that the shielding gas oxygen equivalent strongly influenced the pyrometallurgical reactions that occurred during welding, giving rise to significant changes in weld metal chemical composition, and thus, weld metal microstructure. The Ito-Bessyo Pcm index was modified by incorporating the weld metal oxygen content to allow for better prediction of weld metal phase transformation behavior and cracking susceptibility. Charlie Chong/ Fion Zhang

https://app.aws.org/wj/supplement/WJ_1996_07_s216.pdf

Standard answer: (Linde Gas Reference) Choosing The Right Shielding Gas For Your Needs. Weld metal properties Although weld metal properties are primarily controlled by the consumable composition, the shielding gas can directly influence the strength, ductility, toughness and corrosion resistance of a weld. For instance, adding oxygen and/or carbon dioxide to a shielding gas for MAG welding carbon steel increases its oxidation potential. In general, for a given welding wire, the higher the oxidation potential of a shielding gas, the lower the strength and toughness of the weld. This occurs because the oxygen and carbon dioxide in the shielding gas increase the number of oxide inclusions and reduce the level of materials such as manganese and silicon in the weld metal. Additionally, when MAG welding stainless steel, the amount of carbon dioxide in the shielding gas can have an effect on the corrosion resistance of the resulting weld metal. In particular, carbon transferred into the weld from the gas can produce unacceptably high carbon levels in the welded areas. If those welds are exposed to excessively high heat input during welding or elevated service temperatures, the material is likely to become sensitised to intergranular corrosion due to carbide precipitation. When welding “L”-grade stainless steels, it is important to keep the carbon dioxide level in the gas below 3% to ensure that carbon pick up doesn’t increase carbon in the weld metal above the 0.03% specified maximum for the weld metal in order to prevent sensitisation. Standard stainless steels (non-“L”-grade) benefit from a limited CO2 content since surface oxidation is greatly reduced. All Linde stainless steel MAG welding gases have carbon dioxide levels below 3%.

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http://www.linde-gas.com/internet.global.lindegas.global/en/images/Overview_of_shielding_gases_60734_1217_82202.pdf

Q21. what pressure tests are required on gate valves? Initial Attempt. For gate valves the require pressure testing are: - Shell test - Back seat test - Closure test Comment:

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Standard answer: (API 598 Reference)

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2nd Attempt: Initial Attempt. For gate valves the require pressure testing are: - Shell test - Back seat test - High pressure closure test and - Optional low pressure closure test (Note API598 require floating ball valves to be low pressure closure test, other valve types the low pressure closure test is optional) Comment:

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Q22. what types of valve required back seat test? Initial Attempt. The valves with travelling stem, e.g. gate valve and globe valves required back seat testing (API598) Comment:

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Standard answer: (API 598 Reference)

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Q23. What is the ASME IX "P" number of A516 grade 70 plate? Initial Attempt. ASME “P” number, is the material grouping by chemical content. A516 Gr 70 is P No1, Group 2; where P No 1 is C-Mn-Si steel, Group 2 for material strength. Comment:

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Standard answer: (ASME IX Reference) QW-420 BASE METAL GROUPINGS P-Numbers are assigned to base metals for the purpose of reducing the number of welding and brazing procedure qualifications required. P-Numbers are alphanumeric designations: accordingly, each P-Number shall be considered a separate P-Number (e.g., base metals assigned P-No. 5A are considered a separate P-Number from those assigned P-No. 5B or P-No. 5C). In addition, ferrous base metals have been assigned Group Numbers creating subsets of P-Numbers that are used when WPSs are required to be qualified by impact testing by other Sections or Codes. These assignments are based essentially on comparable base metal characteristics, such as composition, weldability, brazeability, and mechanical properties, where this can logically be done. These assignments do not imply that base metals may be indiscriminately substituted for a base metal that was used in the qualification test without consideration of compatibility from the standpoint of metallurgical properties, postweld heat treatment, design, mechanical properties, and service requirements. The following table shows the assignment groups for various alloy systems:

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2nd Attempt: P-Numbers are assigned to base metals for the purpose of reducing the number of welding and brazing procedure qualifications required, these assignments are based essentially on comparable base metal characteristics, such as (1) composition, (2) weldability, (3) brazeability, and (4) mechanical properties, where this can logically be done. In addition, ferrous base metals have been assigned Group Numbers creating subsets of P-Numbers that are used when WPSs are required to be qualified by impact testing by other Sections or Codes. A516 Gr. 70 is PNo1, Group 2; where PNo 1 is C-Mn-Si steel, Group 2 for impact testing requirements. Comment:

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Q24. List the type of NDT Initial Attempt. The various types of NDT methods are; - Radiographic testing - Ultrasonic testing - Magnetic particle testing - Dye penetrant testing - Electromagnetic testing Comment:

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Standard answer: (ASNT Reference) NDT Test Methods Test method names often refer to the type of penetrating medium or the equipment used to perform that test. Current NDT methods are: Acoustic Emission Testing (AE), Electromagnetic Testing (ET), Guided Wave Testing (GW), Ground Penetrating Radar (GPR), Laser Testing Methods (LM), Leak Testing (LT), Magnetic Flux Leakage (MFL), Microwave Testing, Liquid Penetrant Testing (PT), Magnetic Particle Testing (MT), Neutron Radiographic Testing (NR), Radiographic Testing (RT), Thermal/Infrared Testing (IR), Ultrasonic Testing (UT), Vibration Analysis (VA) and Visual Testing (VT). The six most frequently used test methods are MT, PT, RT, UT, ET and VT. Each of these test methods will be described here, followed by the other, less often used test methods.

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https://www.asnt.org/MinorSiteSections/AboutASNT/Intro-to-NDT

Q25. Which API Specifications apply to the fabrication inspection and testing of valves? Initial Attempt. The API598 specified the inspection & testing of valve as a general requirement. Other specification that specified specific testing and inspection requirements are; - API 6D - API 600 - API ? Comment:

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Standard answer: (API 598 Reference) Metal Plug Valves—Flanged, Threaded and Welding Ends API STANDARD 599 SIXTH EDITION, OCTOBER 2007 7.1 Inspection If inspection by the purchaser is specified in the purchase order and a detailed procedure is not included, inspection shall be in accordance with API 598. If inspection is not specified in the purchase order, the valves shall be capable of meeting the inspection requirements described in API 598. Examination by the manufacturer shall be as specified in API 598. Additional inspection requirements should be specified in the purchase order, if required by the purchaser. 7.2 Testing 7.2.1 Each valve shall be pressure tested in accordance with API 598. Valves shall be tested at the factory in the fully assembled condition, including auxiliary components, fitting and gland packing, and before coating or painting. During the pressure test, the valve body shall be free of external constraints applied in the direction of the pipe axis. Valves having surface conversion treatment may be tested with the treatment applied.

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Standard answer: (API 6D Reference) Specification for Pipeline and Piping Valves API SPECIFICATION 6D TWENTY-FOURTH EDITION, AUGUST 2014 9 Pressure Testing 9.1 General Each valve shall be tested in the final assembled condition prior to shipment. Testing shall be performed in the sequence detailed in 9.3 to 9.4. Backseat test that is only applicable to valves per 9.2 shall be performed before or after the hydrostatic shell test in 9.3. Pressure testing shall be carried out before external coating of the valve. If the valve(s) has been previously tested in accordance with this specification, subsequent repeat hydrostatic and pneumatic testing may be performed without removal of the valve external coating. Test fluid shall be fresh water and shall contain a corrosion inhibitor. Based on the end location of the valve, the test fluid shall have, antifreeze (glycol) added unless otherwise agreed. The water temperature shall not be greater than 100 °F (38 °C) during the testing period.

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Standard answer: (API 600Reference) Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries API Standard 600, Eleventh Edition 7 Testing, inspection and examination

7.1 Pressure tests Each valve shall be given a shell pressure test, a closure tightness test and a stem backseat test in accordance with the requirements of ISO 5208, except as modified herein. Sealing compounds, greases or oils shall be removed from seating surfaces prior to pressure testing. It is permissible, however, for a film of oil that is not heavier than kerosene to be applied to prevent sealing surfaces from galling. 7.1.1 Shell test 7.1.1.1 The shell test shall be at a pressure no less than 1,5 times the pressure corresponding to the valve 38°C pressure rating. The packing gland shall be adjusted so as to maintain the test pressure. 7.1.1.2 The duration of the shell test and the minimum period of time that the shell test pressure is to be sustained, shall be in accordance with table 15.

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2nd Attempt: The API598 specified the inspection & testing of valve as a general requirement. Other API specifications that specified specific testing and inspection requirements relevant to the service conditions are; - API 6D - API 600 Comment:

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Good Luck! Charlie Chong/ Fion Zhang