Piping Question and Answer

PIPING QUESTIONARY  1) What is punch list? List of unfinished work or unmatched item according to DRWG and specifications before Hydro- test. 2)What is the Reason for installing a loop in piping? To ease Expansion and contraction of pipe due to fluid temperature change. 3)What is the Insulation Kit? To isolate between above ground and underground. 4)Type of Supports : Spring support, Hanger support, Dummy support, Shoe, Anchor, Guide and Pick up. 5) Check valve: Designed to permit flow of liquid or gas in a one direction and close if flow reverses. 5) Steam Tracing: To prevent fluid from congealing, forming hydrates, condensing, interfering with operation or causing any damage to piping, equipment and instrument. 6) Vents: Are needed to let gas usually air in and out of service. Basically to remove air pockets from the line. 7) Support types are defined as follows: a) Anchor – a support fixing the piping completely. b) Guide – a support restricting the movement perpendicular to pipe axis, but the axial movement is allowed. c) Hanger – a support hanging the piping. d) Spring – a resilient support which allows vertical movement. e) Resting support – a simple support bearing the pipe weight only. f) Directional stop – a support restricting the movement of a certain direction. g) 3–way restraint - a support restricting the movements of three directions, but permitting rotation. h) Pick up support - a support resting small diameter pipe using large diameter pipe instead of steel structure. 8) Threaded joints checklist: a) What is the maximum diameter piping allowed in hazardous service (1.1/2”) b) What is the minimum sized piping that can be installed on pipe racks (1”) 9)How many threads can be visible after seal welding threaded joints? Zero. Seal welding must cover all threads. 10) What is the gap requirement for socket welds for new construction? 1.5 mm to 3.0 mm gap prior to welding. 11) What is a guide? It controls the horizontal movements of the pipe. 12) Clearances: a) b) c) d)

50 mm rule between all piping and supports. 24” clearance from supports, dead legs, drain and vents. 300 mm from grade at all piping. Fittings, butt welds, etc, adjacent to hangers, clamps, supports, etc must be spaced to allow

MANZARUL KHAN

PIPING QUESTIONARY  freedom of piping movement. Alternatively, flush grind and NDT can be allowed as long as weld location will not restrict piping movement 13) Drip legs: Often made from pipe and fittings, the drip leg is an inexpensive means of collecting condensate. Removal of condensates from steam lines. 14) Piping and Instrument diagram: This drawing is commonly referred to as the P & ID. Its object is to indicate all process and service lines, instrument and controls, equipment and data necessary for the design group. The process flow diagram is the primary source of information for developing the P&ID’S. 15) An Inspection & Test Plan? A mandatory item in the quality plan that guides and assures quality in a Specific type of work in basic sequence of QC activity steps. 16)A Quality Control Procedure? A document that details the specific steps needed to fulfill the QC activity in the ITP. 17) Quality control form? A written documentation detailing a specific activity in the ITP & QC procedure 18) What is a specification? A specification is a guide line to assure that minimum Quality standards are met. 19) What types of inspection action points are found in the ITP? Hold, Witness, Surveillance, Review. 20) What are the differences between the 4 types of inspection points? Detail answer and ensure a clear understanding by candidate. 21) What is a P & ID? Piping and instrument diagram will show the piping layout and detailed notes relating to piping and instrumentation. 22) What is SIS? Safety Instruction Sheet that gives full design details related to a piping system or Line. 23) What is a piping system? Describes the specific service or fluid. 24) What is the piping line class designation? A specific name in alphanumeric designation describes features of a piping system. 25) Show example of a line designation from isometric drawing? ICS1P3 = 150# class, Carbon Steel, 1/16” CA, General hydro carbon. 26) What is an isometric drawing? A detailed piping system / line drawing with reference to construction and material Requirements

MANZARUL KHAN

PIPING QUESTIONARY  27) What things are found in a piping isometric drawing? Line conditions, references to drawings, materials of construction, elevations, Orientation, piping and drawing details and notes, revision control and approval Status. 28) What is a Material list or Material Take off Sheet ( MTO )? Details of materials used in construction of piping, using with isometrics. 29) What is a PIP? Process Industry Practice details requirements for fabrication an Industry Practice. These are often the basis for SA standards. 30) Material Inspection: a)

How do you verify the material? And mention several items to check. Mill Certificate, heat number, color coding and PMI, schedule, rating, Carbon equivalent Value for PREHEAT, diameter, class, grade.

b)

How do you identify fitting and flanges? Correct ratings, sizes, class, schedules as marked on fittings & mill certificates.

c)

How do you check piping for the correct schedule? Use a Vernier Caliper and ensure piping is within tolerances.

d)

What are the tolerances for physical piping straightness and defects? Check the ASTM or API piping specification.

e)

What is standard mill tolerance for piping? 87 ½ % (all) to 115% (greater than 2”), 120% (2” & less) of nominal

f)

How to check Valves of the correct rating and material. CMTRs & trim during Valve testing (Visual inspection)

31) What kind of the inspection required during Gasket installation? Check the Gasket material as per the drawing and specification, size, rating and visual Inspection of surface damages. 32) Explain ‘Spectacle’ plate: Used for Service and shutdown (isolation) for maintenance purposes. 33) What is Jack Screws and when are they required? They are located at flanged connections to facilitate maintenance and removal of flange and Orifice plates to facilitate maintenance. 34) What item to be checked during orifice flange fabrication? Flush Grinding of butt welds of the orifice flange inside and seal welding of orifice tapping Pipes. 35) What are the NDT methods are required during orifice flange installations? Visual and PT / MT.

MANZARUL KHAN

PIPING QUESTIONARY  36) Check list for Reinstatement: # Check that correct bolts and gaskets are installed at all reinstated joints completed and recorded. # Check that all process blinds and spades have been correctly installed as indicated on the P & ID. # Check that spectacle blinds are in the correct position. # Check that correct valves have been installed in the correct ‘Flow’ position. # Check that specified block valves have locking devices correctly installed. # Check that all valves are functioning properly and that spindle has been coated with copa-slip are equal there specified. # Check that relief valve have been correctly installed. # Check that all pump suction strainers have been correctly installed. # Check that correct flow through filters, and strainers, traps, check valves and globe valves. # Release for final equipment alignment. # Hydro test completed. 37) HYDRO TEST PACKAGE REVIEW: 1) P&ID for correct revision. 2) Isometric drawing for correct revision. 3) Isometric Drawing confirm to P&ID. 4) Boundaries of hydro test, filling / draining / vent point and ensure all necessary P & ID’s / Isometric are in the package. 5) Ensure all line listed in test package are identified and test pressure is correct as per LDT. Check blind lists of sizes, thickness and rating. 6)

Check exception list.

38) THE CONTENTS OF TEST PACKAGES ARE: 1) Marked up P&ID and isometric drawings showing the location and type of pipe supports, the boundaries of the test, valve position and the location of Vents, drains, temporary blinds (size and thickness), the water fill point And pressure gauges. 2) The test medium and pressure. 3) A piping line list. 39)THE CHECK LIST FOR PIPING WORK COMPLETION NEEDS TO BE CONFIRMED BEFORE THE PRESSURE TEST CAN COMMENCE: CHECK LIST IS AS FOLLOWS:

MANZARUL KHAN

PIPING QUESTIONARY  1) 2) 3) 4) 5) 6) 7) 8) 9)

Piping should be Correct Dimension, Location and Orientation. Welding Completed. NDE Completed. PWHT and Hardness Test Completed. Valve, in line item and line Equipment Completed. Support and Hanger installation Completed. Material Thickness Verification / Color Code P&ID Walk through in accordance with Isometric drawings. All instruments are disconnected or not.

40) BEFORE THE TESTING COMMENCES SOME OF THE GENERAL REQUIREMENT TO BE CHECK AND REVIEW. 1) Test Pressure to be used shall not less than 1.5 times the design pressure. 2) Water to be used shall be fresh water and free from sediments. The Maximum Chloride content shall be less than 30 ppm. 3) For Pneumatic testing, the test medium shall be Air or any other non-flammable gas and the test pressure shall be 110 % of the design pressure. For pneumatic test, the soap solution spray shall be used during leakage detection. 4) The Temporary supports are to be examined to ensure that they will adequately support the line during testing.

41)TEST SEQUENCES ARE: 1) Filling Test System Completely with water or Air. 2) Fill the water from the down side. 3) Open all vent valves during Water filling. 4) Applying pressure gradually until the specified test pressure is reached. 5) Holding time is 10 minutes minimum. The test pressure is attained until all welds and connection have been examined (Shall not over pressurize the system). 6) After the test, the system was drained to minimize standing water in the line. Air blowing to be performed to remove the remaining water. 42)VALVE INSPECTION AND TESTING: (API 598) The following tests and examinations are specified in this standard. a) b) c) d) e)

Shell Test. Back Seat Test. Low Pressure Closure Test. High Pressure Closure Test. Visual Examination of Castings.

43)THREE ADVANTAGES OF USING STUD BOLTS ARE : 1.The stud bolt is more easily removed if corroded. 2.Confusion with other bolts at the site is avoided. 3.Stud bolts in the less frequently used sizes and materials can be readily made from round stock. 44) ACCEPTANCE CRITERIA FOR INSPECTION OF 6” DIA, SCH. 40 BUTT WELD JOINT: a) Bevel Angle ………………………. 37.5° (tolerance ± 2.5°) b) Root Gap…………………………... 1.6mm (tolerance ± 0.8mm) c) Internal Alignment (Hi- Lo)……… 1.6mm below. d) Root Face…………………………...1.6mm (tolerance ± 0.8mm)

MANZARUL KHAN

PIPING QUESTIONARY  45) TWO REASONS FOR HAVING VENT HOLE ON REINFORCING PAD OF BRANCH CONNECTION : To reveal leakage in the weld between branch and header. To allow venting during welding and heat treatment 46) Non corrosive fluids Services where impurities are accepted industrial water lines (cooling water) steam lube oil return / before filter lines air lines vents and drains Carbon Steel, Low Alloy Steel (High T) 47) Corrosive fluids Services where impurities are not accepted demineralized water lube oil after filters fuel gas / oil sea water (water containing Chlorine) Stainless Steel No Iron (Fe) Copper/ Nickel Alloys (Cu- Ni) 48) Give typical material specifications for – CS flanges : A105 – forgings / A 216 Gr. WCB – castings / A 515 Gr.70 – Plates. SS flanges : A 182 Gr.F304 - forgings / A 351 Gr.CF3 - castings / A 240 Gr.304 – Plates. LTCS flanges : A 350 Gr. LF3 – forgings / A 352 Gr. LC3 – castings / A 203 Gr.E – Plates. AS flanges : A 182 Gr.F11 CL 2 - forgings / A 217 Gr.WCB - castings / A 387 Gr.11 CL.2 – Plates. 49) What is the difference between (1) SS 304 and SS 304 L - 304 L is low Carbon C ≤ 0.03%. (2) SS 304, SS 316 and SS 321. SS 304 – 18 Cr. and 8 Ni. Where as SS 316 contains Molybdenum 2 to 3 %. SS 321 as the same chemical composition of SS 304 but in addition to that it contains Ti which is a stabilizer 50) What is the function of a steam trap? Function of the Steam trap is to remove the condensate. 51) What are the 3 precautions that has to be taken during the welding of Orifice flanges ? 1) Welding nearer to the flanges shall be flush ground to avoid any turbulence. 2) The orientation of the tapping holes shall be maintained. 3) No bends shall be available nearer to the flange it shall be straight for a distance of atleast 5 times the Diameter of the pipe on the Up stream.

MANZARUL KHAN

PIPING QUESTIONARY  YERP-SAES-L-100 APPLICABLE CODES AND STANDARDS FOR PRESSURE PIPING SYSTEMS YERP-SAES-L-105 PIPING MATERIAL SPECIFICATION YERP-SAES-L-108, SELECTION OF VALVES YERP-SAES-L-109, SELECTION OF FLANGES, STUD BOLTS AND GASKETS YERP-SAES-L-110 LIMITATIONS ON PIPE JOINTS AND COMPONENTS YERP-SAES-L-120 PIPING FLEXIBILITY ANALYSIS YERP-SAES-L-125 SAFETY INSTRUCTION SHEET FOR PIPING AND PIPELINES YERP-SAES-L-130 MATERIAL FOR LOW TEMPERATURE SERVICE YERP-SAES-L-131 FRACTURE CONTROL OF LINE PIPE YERP-SAES-L-132 MATERIAL SELECTION FOR PIPING SYSTEMS YERP-SAES-L-133, CORROSION PROTECTION REQUIREMENTS FOR PIPELINES, PIPING AND PROCESS EQUIPMENT YERP-SAES-L-136 SELECTION AND RESTRICTIONS OF CARBON STEEL PIPE YERP-SAES-L-140 THERMAL EXPANSION RELIEF IN PIPING YERP-SAES-L-150, PRESSURE TESTING OF PLANT PIPING AND PIPELINES YERP-SAES-L-310 DESIGN OF PLANT PIPING YERP-SAES-L-350 CONSTRUCTION OF PLANT PIPING YERP-SAES-A-004 GENERAL REQUIREMENTS FOR PRESSURE TESTING YERP-SAES-A-005 - SAFETY INSTRUCTION SHEET YERP-SAES-A-007 HYDROSTATIC TESTING FLUIDS AND LAY-UP PROCEDURES YERP-SAEP-351 BOLTED FLANGE JOINTS ASSEMBLY YERP-01-SAMSS-Y020 BASELINE THICKNESS MEASUREMENT

MANZARUL KHAN