Exxon IP 3-12-1 Valve Selection

Valve Selection

IP 3-12-1 Page 1 of 11

INTERNATIONAL PRACTICE

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998 Changes shown by 

SCOPE I I

1.1 1.2

This practice covers requirements for valve selection excluding control valves and pressure relief valves. An asterisk ( ) indicates that additional information is required. If a job is contracted, this information is furnished in the Job Specification.

SUMMARY OF ADDITIONAL REQUIREMENTS I I

2.1 2.2

Table 1 lists the practice and standards which shall be used with this practice. Table 2 lists the practice, code, standards and specification which shall be used with this practice as specified by the Purchaser. TABLE 1 PRACTICE IP 3-12-9

General Requirements for Valves STANDARDS

ASME Standard B16.34

Valves - Flanged, Threaded, and Welding End

API Standards 594 600 602 603 608 609

Wafer and Wafer-Lug Check Valves Steel Gate Valves, Flanged and Buttwelding Ends Compact Steel Gate Valves-Flanged, Threaded, Welding, and Extended-Body Ends Class 150, Cast, Corrosion-Resistant, Flanged-End Gate Valves Metal Ball Valves, Flanged, Threaded, and Welding End Butterfly Valves, Lug-Type and Wafer-Type

ASTM Standard A 494 / A 494M

Castings, Nickel and Nickel Alloy

ANSI / AWWA Standard C504 Rubber Seated Butterfly Valves

TABLE 2 PRACTICE IP 19-1-1

Paint and Protective Coatings CODE, STANDARDS AND SPECIFICATION

ASME Code B31.3

Process Piping

ASME Standard B1.20.1

Pipe Threads, General Purpose (Inch)

API Standard 607

Fire Test for Soft-Seated Quarter-Turn Valves

MSS Specification SP-25

Standard Marking System for Valves, Fittings, Flanges, and Unions

DEFINITIONS I

3.1

I

3.2

I

3.3

Onstream equipment isolation as used herein indicates the removal from service of equipment or a unit for the purpose of repairs, cleaning, or inspection while the remainder of the plant continues in operation. Equipment includes pumps, compressors, steam turbines, dryers, vessels, and fired heaters either provided with a spare or able to be bypassed. Product segregation to prevent contamination. The prevention of fluid mixing which would result in unacceptable contamination of either fluid. Segregation for safety. The segregation for safety of fluids which could result in an explosive mixture such as at cyclic POWERFORMING unit reactor and regeneration block valves. THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 2 of 11 Rev. 1

March 1998

(This practice is appropriate for attachment to Inquiry or Purchase Document)

INTERNATIONAL PRACTICE

I

3.4

Line service classification defines the design pressure, design temperature, material, and corrosion allowance of a piping system. Dangerous materials, for purposes of this practice, include the following: a. Toxic materials such as phenol, hydrogen sulfide, chlorine. b. Highly corrosive materials such as acids, caustic and other similar materials. c. Flammable materials (including light hydrocarbons lighter than 68 degrees API). d. Boiler feedwater and steam, in systems requiring ANSI Class 300 and higher flange ratings. e. Oxygen in concentrations greater than 35%. Non-dangerous materials, as used herein, include all materials not listed as dangerous per Par. 3.5.

I

3.5

I

3.6

I

3.7

Combustible liquids. High flash liquids [flash points 100°F (38°C) or higher] when handled at temperatures 15°F (8°C) below their flash point and lower.

I

3.8

Flammable liquids. Low flash liquids [flash point below 100°F (38°C)]; and high flash liquids [flash point 100°F or higher] when handled at temperatures above or within 15°F (8°C) of their flash points.

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3.9

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3.10 3.11

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3.12

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3.13

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3.14

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3.15

Flammable materials. Flammable liquids; hydrocarbon vapors; and other vapors, such as hydrogen and carbon disulfide, that are readily ignitable when released to atmosphere. Block Valve refers to any valve used to stop flow, typically, an on/off valve. Valve Type: a. Wafer type valve describes a valve type which is installed between mating pipe flanges and held in place by the compressive force produced by the mating flange bolt forces. The flange bolts are exposed. b. Lug style valves are single flange valves where ALL the flange bolts are covered by the valve body material. The valve is held in place either by the compressive force produced by the mating flange bolt forces (preferred method) or by the use of machine bolts threaded into the valve body. c. Flanged valves are the conventional double flanged valves. d. Welding End Valves (Buttweld end) are conventional valves with buttwelding ends. Emergency block valves (EBV). Type A is a manually operated valve located at the equipment nozzle. Type B is a manually operated valve located in the piping system at least 25 ft (7.5 m) from the equipment protected. Type C is a power operated valve located in the piping system located at least 25 ft from the equipment protected with the actuator button mounted on the actuator. Type D is a power operated valve located anywhere in the piping system with a remotely located actuator button at least 40 ft (12 m) from the equipment protected. Soft seals are defined as resilient sealing elements located in the body seating and/or closure components. Wet H2S is defined as greater than 50 wppm of H 2S in a water phase (determined by using the total amount of sulfide in the water phase) or ≥ 0.05 psia (0.34 kPa abs) H2S partial pressure in the gas phase with liquid water present. Corrosion Inhibitor. An additive to inhibit corrosion between two materials. There are active and passive corrosion inhibitors.

I I

3.16 3.17

Slurry Service. Streams having a solids content greater than 0.1 lb/gal (11.98 kg/m 3). Fire-Tested. For the purpose of this practice means compliance with API Standard 607, fourth edition or later.

MATERIALS R



4.1

Unless otherwise specified by Owner or by the block valve requirements of Table 6, trim material selection for carbon steel or low alloy (up to 9% chrome) gate, globe and check valves shall be in accordance with Table 3.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 3 of 11

INTERNATIONAL PRACTICE

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998

TABLE 3 TRIM REQUIREMENTS SERVICE

NOMINAL TRIM MATERIAL (PER API-600)

a)

Caustic

Trim #1, or #8

b)

Water, Air, or Inert Gas

Trim #1, or #8

c)

Hydrocarbon service 68 deg API (0.709 relative density) and heavier and other lubricating type service

Trim #1, or #8

d)

Hydrocarbon service lighter than 68 deg API including vapor (non-lubricating service)

e)

Up to 900°F (480°C) maximum fluid design temperature

Trim #8

Over 900°F (480°C) maximum fluid design temperature

Trim #5

Steam, boiler feedwater and condensate Class 150 and 300

Trim #8

Class 600 and higher f)

Wet H2S (1)

Trim #5 Trim #2, #3, #5, #8 , #9, #10, #11, #12, #13 or #14

Note: (1) For wet H2S services, see hardness requirements stipulated in IP 3-12-9.

R

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R

4.2

4.3

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4.4

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R

R

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4.5

4.6





For all non-oxidizing environments and for oxidizing environments ≤ 1000°F (538°C) process temperature, pure graphite (minimum 95% carbon content) packings and interlaced braided graphite end retainer rings shall be used unless otherwise specified. Density of graphite preformed rings shall be 70 to 90 lb/ft 3 (1120 to 1440 kg/m 3). All packing rings shall contain corrosion inhibitor. c. Except for certain acid services and oxygen, fire-tested valve stem packing materials shall be used in flammable, combustible or dangerous material services. Cast Monel valve material shall be specified per ASTM A 494 / A 494M Grade M-35-1 or Grade M-30C. The supplemental Weldability Test S-2 (per A 494 / 494M) shall be specified. Limitations on the use of copper, and copper based alloys, shall be as given below for the following services: a. Ammonia: Alloys with a copper content greater than 50% shall not be used in ammonia service or in aqueous solutions containing ammonia where the pH exceeds 8.5. b. Caustic and alkaline: Alloys with a copper content less than 85% shall not be used. c. Acetylene: Alloys with a copper content greater than 50% shall not be used in services where acetylene in a wet environment is present. 17-4PH stainless steel valve stems, shafts, hinge pins and their integral components, shall not be used for design temperatures greater than 750°F (400°C). 17-4PH stainless steel is an acceptable substitute for 13 Cr when the material and heat treatment comply with ASME SA-564, Type 630, condition double 1150. b.



R

Austenitic stainless steel (types 304, 316, 321, and 347), Monel, and nickel alloy valves shall have trim, gland bolts and nuts, and yoke bolting of the same nominal chemistry as the body. When Trim #5 is required by Table 6, AWS Specification A5.13 E/R CoCr-A hardfacing shall be provided for body and gate seats. AWS Specification A5.13 E/R CoCr-A hardfacing is always an acceptable alternative for seating surfaces. Material for valve stem packing and seals shall comply with the following: a. Materials shall be suitable for the fluid service and for the maximum and minimum fluid design temperatures to which these components will be exposed. As a minimum, stem packing for valves in hydrocarbon or steam service shall be suitable for 1000°F (538°C) process temperature.

4.7

Monel shall not be used in H2S service above 400°F (205°C) or Catacarb service.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 4 of 11 Rev. 1

March 1998

R

4.8

(This practice is appropriate for attachment to Inquiry or Purchase Document)

INTERNATIONAL PRACTICE

For butterfly valves for water service, valve materials shall be per ANSI/AWWA C504 except as modified below: 

SERVICE (1)

Fresh Water

Brackish or Salt Water

BODY LINING

Not Throttled

Buna-N rubber seat (full lining not required)

Throttled

Buna-N rubber

Not Throttled

Buna-N rubber

Throttled

SHAFT Monel; or Austenitic Stainless Steel Monel; or Type 316 Stainless Steel

DISC Bronze; or Austenitic Stainless Steel Bronze per ASTM B584 Alloy C90500: or Type 316 Stainless Steel (2) Monel; or Type 316 Stainless Steel (2)

Notes: (1) A valve is considered to be in throttling service when the disc is at an angle greater than 10 degrees from the full open position during normal operation. (2) Type 316 stainless steel shall not be used in services where the fluid (line) velocity, with the disc in its normal operating position, is less than 3 ft/sec (0.9 m/s) or where the disc is normally closed.

APPLICATION AND LIMITATIONS ON USE S

5.1

R,O 

5.2

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5.3





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5.4

S,R

5.5 

GENERAL a. All valves shall be suitable for the line service classification. b. Single or double valves at a classification change shall be suitable for the more severe line classification on either side of the valve(s) location. c. Valves around control valves (upstream, downstream, and bypass) shall be of the same Class rating as the most severe line classification. Gate and globe valves shall have flanged ends, bolted bonnet, and shall be OS & Y (outside screw and yoke). Deviations from these requirements, if any, shall be specified. COMPACT AND EXTENDED BODY STEEL VALVES a. Threaded and socket welding steel gate valves per API-602 and steel globe valves conforming to the applicable requirements of API-602 may be used within the following limits: 1. Valves shall be OS&Y (outside screw and yoke). 2. The specified line corrosion allowance is 1/8 inch (3 mm) or less; or, if the specified valves have a thickness in excess of the minimum API-602 specified thickness, the additional thickness may be considered as additional corrosion allowance. 3. Valves shall be bolted bonnet unless welded bonnet is specified. Bonnet welds shall be maximum 225 Brinell hardness. b. Flanged valves per API-602 are not acceptable. API-603 VALVES API-603 valves shall not be used where the specified corrosion allowance of the connecting pipe exceeds 0.03 in. (0.8 mm). DUCTILE IRON, CAST IRON, LOW MELTING POINT ALLOY VALVES a. Ductile (nodular) iron valves, either austenitic or ferritic, may be used within the limits of ASME B31.3 provided the installation is approved by the Owner’s Engineer. Usage in hydrocarbon or dangerous material services require approval by the Owner’s Engineer. b. Cast iron valves may only be used in water service not subject to freezing. c. Low melting point alloy valves, such as aluminum, brass or bronze, shall not be used for services in which failure of the valve in a fire would increase the hazardous condition. Examples are: Prevent steam flow to any process pump, steam header, or emergency steam line. d. Low melting point alloy valves, such as aluminum, brass and bronze, shall not be used in hydrocarbon service.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 5 of 11

INTERNATIONAL PRACTICE

R

5.6 

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998

SOFT SEATED VALVES a. When specified, soft seated valves in liquid service shall be provided with pressure relief for body cavities. The liquid shall be relieved to the upstream side, unless otherwise specified. b. The maximum design temperature limitation on soft seal material shall be as follows: TABLE 4 SOFT SEAL MATERIAL TEMPERATURE LIMITS TEMPERATURE LIMIT °F

°C

PTFE

450

230

FEP

400

200

VITON - A

400

200

BUNA N

250

120

NEOPRENE

200

90

SOFT SEAL MATERIAL

S

c.

R

5.7 

R

5.8



Soft seated ball, plug and butterfly valves: 1. Non-fire-tested type ball, plug, or butterfly valves shall not be used in flammable material or other dangerous material services regardless of operating temperature, except for certain acid services. 2. Fire-tested type ball, plug, and butterfly valves greater than NPS 4 shall not be used as the first block valve for the holdup of large volumes of dangerous liquid materials (>10,000 gal. (38000 l) liquid hold up ). 3. Fire-tested butterfly valves per API 609 category B may be used in dangerous material services, and other process and general services subject to the following limitations: (a) The design shall be bi-directional, or shall meet the design temperatures and pressures specified for the preferred and non-preferred flow directions, respectively. (b) Where “double block and bleed” capability is specified, the installation shall consist of two valves with a spool piece and bleed valve between. 4. Soft seated ball, plug and butterfly valves shall not be used as block valves to the atmosphere. BUTTERFLY VALVES - GENERAL a. Where butterfly valves are used adjacent to process equipment that requires depressurizing and removal for maintenance or other purposes, the valves shall be of the flanged type. b. Butterfly valves shall be limited to NPS 3 and larger. SOFT-SEALED BUTTERFLY VALVES - FIRE-TESTED a. Unless otherwise specified, shaft material shall be as follows: 1. 13Cr, except for valves with austenitic stainless steel bodies. 2. 18Cr 8Ni for valves with austenitic stainless steel bodies. b. Unless otherwise specified, disc material shall be as follows: 1. 18Cr 8Ni 2. Carbon steel, overlayed with 18Cr 8Ni, 0.060 in. (1.5 mm) minimum finished thickness 3. Cr plated discs are not acceptable. c. AWS Specification A5.13 E/R CoCr-A hardfacing shall be provided on seating surfaces when specified.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 6 of 11 Rev. 1

March 1998

R

5.9

BUTTERFLY VALVES FOR WATER SERVICE a. Valves shall be per ANSI/AWWA C504 and the additional requirements of this practice. b. Shaft diameters shall be selected per ANSI/AWWA C504 Class “B” valves. c. Rubber lining of valve bodies shall be as follows: 1. The wetted surfaces of valve bodies shall be fully lined, except that only a bonded rubber seat insert is required for non-throttling fresh water services. 2. The lining shall extend across the full flange face, and shall have a minimum thickness of 1/4 in. (6 mm). 3. The rubber lining shall be 100% bonded to the body, flange and the metal seat insert, if any. The lining-to-body bond shall meet the ANSI/AWWA C504 seat-to-body bond requirements. The lining-to-seat bond shall be capable of withstanding a 160 psi (1100 kPa) tensile load. 4. The minimum thickness of rubber at the body seating surface shall be as given below: VALVE NOMINAL SIZE

MINIMUM RUBBER THICKNESS Angle Seating

90° Seating in. 3-4 6 8-10 12-14 16-20 24 30-48 54-72

R,C

5.10

S S

5.11

INTERNATIONAL PRACTICE

(This practice is appropriate for attachment to Inquiry or Purchase Document)

mm 80-100 150 200-250 300-350 400-500 600 750-1200 1350-1800

in. 1/4 5/16 3/8 7/16 1/2 3/4 1 1

mm 6 8 9 11 13 19 25 25

in. 5/16 5/16 5/16 3/8 3/8 1/2 1/2 5/8

mm 8 8 8 9 9 13 13 16

REDUCED PORT VALVES Reduced port or smaller than line size valves (with reducers) may be used instead of full port valves, provided: a. The increased pressure drop and reduced section modulus is considered in the design of the piping. b. Such valves are not used in horizontal lines sloped for continuous draining. c. Drains are installed at all additional low points caused by the installation of such valves. d. They are not used in erosive applications such as slurries, fluidized solids, or severe fouling or coking services. e. They are not to be used in pressure relief valve inlet or outlet piping, or in flare headers. f. They are not used in lines specified to be “pigged." WAFER AND LUG TYPE VALVES a.

For design temperature greater than 600°F (315°C) wafer and lug type valves shall not be used. At 600°F and lower a lug type valve must be used for hydrocarbons and dangerous services.

b.

Wafer or lug type valves shall not be used as the first block valve against storage tanks or vessels.

c. R

5.12



For design temperature exceeding 400°F (200°C) the body material of wafer or lug type valves shall have the same nominal coefficient of thermal expansion as the bolting material and adjacent flanges. CHECK VALVES a. Dual and single plate wafer check valves per API-594 shall not be used in reciprocating compressor or reciprocating pump service. b. Union bonnet ball check and lift check valves (straight-through type) use shall be limited to portions of piping systems where pipe unions are permissible. c. Valves shall be of the self-closing type (gravity or spring assisted) and shall not depend on flow reversal, or only the spring, to effect closure. d. Lift check valves shall not be used in services subject to fouling, coking deposits, or erosion. e. The need for and design of external assist or damping devices for the specified check valve type in a specific compressor discharge service shall be based on the full range of operating flow conditions. f.

For design temperature > 600°F (315°C), threaded retainer plugs for hinge pins shall be seal welded if valves are used in flammable materials service.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

Valve Selection

Page 7 of 11

INTERNATIONAL PRACTICE

R

5.13 5.14

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S S

5.15  

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5.16

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5.17

R

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5.18

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R

5.19 

IP 3-12-1

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998

KNIFE GATE VALVES Knife gate valves shall not be used in dangerous material service. BALL VALVES a. Ball valves shall be per API-608 when applicable. b. Chrome plated balls are not acceptable. The use of other types of metallic plated balls shall be approved by the Owner’s Engineer. c. All valves with hollow-ball construction shall be provided with pressure relief for the body cavity. Pressure shall relieve to the upstream side of the valve unless otherwise specified. Final design shall be approved by the Purchaser. d. Valve handle shall be heat resistant and capable of withstanding direct exposure to fire without becoming unusable. EMERGENCY BLOCK VALVES (EBV) IN ISOLATION SERVICE a. Valves shall be flanged, unless buttwelding end valves are approved by the Owner’s Engineer. b. Plug valves shall be lubricated fire-tested type, and require the Owner's Engineer approval. c. Expanding seal fire-tested plug valves may be used in clean, non-corrosive services. d. Metal-seated ball valves; or metal-seated, fire-tested butterfly valves are acceptable if graphite packing and gaskets are used. e. Fire-tested soft seated ball, plug or butterfly valves may be used as EBV's in hydrocarbons, dangerous or flammable service up to NPS 4. f. Motor actuated valves. Unless otherwise specified, valves designated as Type B that are size NPS 10 (250 mm) and larger, or that are rated greater than ASME Class 300 - regardless of size, shall be motor actuated. This criteria also applies to “Battery Limit (BL)" valves if they are in flammable material or dangerous material services. g. Chainwheel operation is not permitted. VALVES FOR LOW TEMPERATURE SERVICE Valves in low-temperature service shall have extended bonnets (so that the packing gland is removed from the cold zone) per the following: a.

All valves with a service temperature below -150°F (-100°C), and

b.

Valves with PTFE packing with a service temperature below -80°F (-62°C).

c. Extended bonnets shall not be insulated. PRESSURE SEAL BONNET VALVES The use of Pressure-seal bonnet valves must be approved by the Owner’s Engineer. Their use is limited to Class 900 and higher, and proposals shall address suitability in corrosive services. END CONNECTIONS a. Threaded and socket welding end connections shall be limited to NPS 2 and smaller. b. Valves larger than NPS 2 shall be flanged except: 1. Steam services requiring Class 600 and above may have buttweld ends. 2. The use of buttweld ends for services other than steam for Class 600 and above requires the Owner's Engineer approval. c. Surface finish on raised face flanges shall be 125 to 250 micro inches Ra. THREADED OPENINGS AND PLUGS a. Threads shall be per ASME B1.20.1. b. All threaded openings shall be plugged with solid, round or square head plugs of wrought material having the same nominal composition as the body or a comparable material approved by the Owner’s Engineer. Plugs shall not be made from cast material.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 8 of 11 Rev. 1

March 1998

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5.20

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INTERNATIONAL PRACTICE

(This practice is appropriate for attachment to Inquiry or Purchase Document)

VALVE POSITION INDICATORS a. For slurry service a valve indicator shall be provided that gives position indication of the fully closed position. b. All quarter turn valves shall have an approved method for valve position indication. Manual operators shall be designed so that they can only be installed one way on the valve stem. It's position shall indicate the status of open/close position.

MANUAL GEAR OPERATORS FOR VALVES O



6.1

Manual gear operators shall be supplied for valves per Table 5. Gate and globe valves shown in the table shall be supplied with gear operators only if they are operated more than four times a year, or are designated as a critical valves. TABLE 5 SIZE REQUIREMENTS FOR GEAR OPERATORS VALVE TYPE AND MINIMUM SIZE (NPS) CLASS RATING

GATE OR GLOBE

BALL OR PLUG

in.

mm

in.

mm

in.

mm

125, 150, 250

14

350

6

150

6

150

300(1)

10

250

6

150

6

150

400

8

200

6

150

4

100

600

8

200

6

150

4

100

900

6

150

4

100

(2)

(2)

1500

4

100

3

80

(2)

(2)

2500

3

80

3

80

(2)

(2)

Notes: (1) Includes ASME Class 300 ductile iron. (2) This valve type not generally available above ASME Class 600.

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6.2

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6.3

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7.1

Manual gear operators (when required) shall be specified to close or open in not more than 30 turns for butterfly, ball and plug valves. For gate valves, the turns shall not exceed 15 for valves up to NPS 10, 30 for valves up to NPS 20, and 50 for valves up to NPS 30. Turns will be specified for larger valves. The rim pull shall not exceed 80 lbs (38 kg). Clamp-on type chainwheels for valves greater than NPS 2 (50 mm) are not permitted unless approved by the Owner’s Engineer.

BLOCK AND BLEED VALVES BLOCK VALVES Table 6 gives block valve requirements for the following services: a. Onstream equipment isolation (including instruments). b. Product segregation to prevent contamination. c. Segregation for safety. d. Slurry service. e. General (Other) service applications.

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

Valve Selection

Page 9 of 11

INTERNATIONAL PRACTICE

S

7.2

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7.3 

S S

R R

S C

7.4

R

7.5

R

7.6

IP 3-12-1

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998

DOUBLE BLOCK VALVES a. Double block valves with bleeders when “Double” valves are required by Table 6 shall consist of two valves with an intervening section of pipe fitted with a bleeder, or two valves bolted together with an intervening bleeder installed in position C or D per ASME B 16.34. No connection other than the bleeder shall be made between the block valves. b. Double block valves shall be used when a single valve may be rendered inoperable due to autorefrigeration of a volatile fluid. The valves shall be separated by at least six inches of pipe. A bleeder, in this case, is not required. c. When specified by the Owner’s Engineer, double block valves with bleeders shall be provided to isolate equipment that has a spare or may be bypassed temporarily if it is probable a single block valve will become corroded, eroded, or fouled such that the installation of a blind would be difficult. BLEED VALVES A single bleed valve, plugged, capped, blinded, or piped to a safe location when specified, shall be provided for all required applications. Bleed valves shall be NPS 3/4 minimum and shall have threaded outlets. Except for the exclusions listed in Par. 7.4, bleed valves shall be located as follows: a. Between all double block valves required by Table 6. b. For pressure relieving (PR) devices: 1. Between the PR device and the inlet block valve. 2. Between the PR device and the outlet block valve when the PR device discharges to a vessel, or to pressurized piping other than a flare pipe header. 3. For all shell-and-tube and double pipe heat exchangers, when a manually operated bleeder valve is used for overpressure protection against liquid thermal expansion, the valve shall be installed on the cooler side. c. When a body bleed is required by Table 6, the bleed valve should be located on the block valve body (position G or H, ASME B16.34 Figure 1 for gate valves) for valves NPS 3 (75 mm) and larger. d. Between the block valve and the associated equipment item for all onstream equipment isolation applications. A drain valve already specified in this location, and not piped to a closed drain system, is sufficient to meet this requirement. e. Between the block valve and isolation blind for onstream isolation of equipment in dangerous material services, unless the block valve is equipped with a body bleed. BLEED VALVES ARE NOT REQUIRED FOR: a. Single and double block valves at instrument takeoff connections. b. Double block at vents, drains, flushing and cleaning connections. c. Where PR devices are installed for thermal liquid expansion protection. SLURRY SERVICE The specified bleed valve between double block valves shall be on the valve body (position C or D, ASME B16.34 Figure 1 for gate valves). WEDGES Wedges for gate valves shall be flexible type except solid wedges may be used as follows: a. Class 150, any size b. NPS 2 or smaller, any Class c.

Single valves in double block and bleed applications with a specified design temperature ≤ 400°F (204°C).

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 10 of 11 Rev. 1

March 1998

(This practice is appropriate for attachment to Inquiry or Purchase Document)

INTERNATIONAL PRACTICE

TABLE 6 BLOCK AND BLEED VALVE REQUIREMENTS FLUID DESIGN TEMP

SIZE

TRIM FOR GATE OR GLOBE VALVE(2)

VALVE BODY BLEED VALVE REQUIRED

Any

Double

Per Table 3

No

SERVICE

FLUID

ONSTREAM EQUIPMENT ISOLATION

Dangerous material

(including instruments) such as at:

AS AN ALTERNATIVE TO DOUBLE VALVES, SINGLE VALVES MAY BE USED AS FOLLOWS: Dangerous material Single Per Table 3 No T ≤ 1000°F ≤ Class 600 ≤ NPS 2

a)

b) c) d)

Spared Equipment and Equipment capable of being bypassed Process unit limits Storage tanks and vessels Control valve stations (excluding bypass valves)

Flammable materials (including light hydrocarbons lighter than 68 degrees API) OR Boiler feedwater and steam, in systems requiring Class 300 and higher flange ratings OR Oxygen in concentrations greater than 35%. Any Any Non Dangerous

PRODUCT SEGREGATION TO PREVENT CONTAMINATION such as at: e) Jumpover connections between product lines f) Unit by-passes such as around reactors SEGREGATION FOR SAFETY such as at: g) Cyclic Powerformer reaction and regeneration valves

T ≤ 1000°F ≤ Class 600

> NPS 2 and Class 150

T ≤ 1000°F

≤ NPS 10

Single

Trim #5

No

Class 150

> NPS 10

Single(1)

Trim #5

Yes

Class 300

> NPS 2

Single(1)

Trim #5

Yes

T > 1000°F

Any

Any

Double

Per Table 3

Yes

Any

> Class 600

Any

Double

Per Table 3

Yes

T ≤ 1000°F ≤ Class 600

Any

Single

Per Table 3

No

T ≤ 400°F

≤ Class 300

Any

Single(3)

Per Table 3

Yes

T > 400°F

Any

Any

Double

Per Table 3

Yes

Any

> Class 300

Any

Double

Per Table 3

Yes

Any

Any

Any

Double

Trim #5(4)(5)(6)

Yes

T ≤ 400°F

Any

Any

Single

Per Table 3

No

T > 400°F

Any

Any

Double

Per Table 3

Yes

T ≤1000°F

≤ Class 600

Any

Single

Per Table 3

No

T >1000°F

Any

Any

Double

Per Table 3

Yes

Any

> Class 600

Any

Double

Per Table 3

Yes

Any

Any

SLURRY SERVICE Any OTHER SERVICES(7) such as at: h) Pressure relieving systems i) Control valve bypasses j) Vents, drains flushing and cleaning connections k) Sample outlet piping

CLASS

NUMBER OF VALVES (ANY TYPE)

Any

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

IP 3-12-1

Valve Selection

Page 11 of 11

INTERNATIONAL PRACTICE

(This practice is appropriate for attachment to Inquiry or Purchase Document)

Rev. 1

March 1998

TABLE 6 (Cont) Notes: 

(1)

 

(2) (3)



(4) (5) (6) (7)

A closure test for double block and bleed per API 598 is required. The test pressure shall be specified by the Owner’s Engineer. Trim for austenitic SS, Monel and Nickel Alloy valves shall be per Par. 4.2. A single valve shall be soft-sealed “double block and bleed" gate, plug, or ball type. A closure test for double block and bleed per API 598 is required. The test pressure shall be equal to the valve design pressure specified by the Owner’s Engineer. Subject to Owner’s Engineer approval, the use of single resilient seated butterfly valves is permitted where zero leakage has been demonstrated by past experience or test, and leak detection facilities are provided. In this case body bleeds are not required. All seat rings shall be seal welded to the valve body. The backseat bushing shall be hardfaced with Co Cr A. Valves cycling ten or more times a year shall have wedge guides hardfaced with Co Cr A. Use Co Cr A hardfacing on both wedge gate and seats for non-13 Cr materials selected in accordance with Table 3. Including Block valves not falling into other application categories. Acceptable Metric Equivalents 400°F

205°C

1000°F

540°C

Revision Memo 9/68 6/70 1/72 1/73 1/74 6/75 1/80 6/80

Original Issue of Basic Practice Revision 1 Revision 2 Revision 3 Revision 4 Revision 5 Revision 6 Revision 7

6/82 1/84 1/85 1/86 6/86 3/90 12/91 12/93

Revision 8 Revision 9 Revision 10 Revision 11 Revision 12 Revision 13 Revision 14 Revision 15

6/97 3/98

Revision 0 - Original Issue of International Practice Revision 1 Editorial revision. Deletion of “Purchase Document” purpose in title block. Par. 4.6 Addition of valve parts permitted as 17-4 pH material from IP 3-12-9. Par. 5.2 Addition of gate and globe valve requirements from withdrawn IP 3-12-2. Par. 5.3a-3 Addition of compact valve requirements from withdrawn IP 3-12-5. Par. 5.12f Addition of check valve requirement from withdrawn IP 3-14-2.  Exxon Research and Engineering Company, 1997, 1998

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.