piping codes, valve standards and ball valve · pdf fileengineered & process valves valve...
TRANSCRIPT
Piping codes, valve standards
and
ball valve selection
Ron Manson, March 2015
ENGINEERED & PROCESS VALVES
Valve Requirements for Piping Codes -
2
ASME B31.1 - Power Piping, 2014
ASME B31.3 - Process Piping, 2012
ASME B31.4 - Pipeline Transportation Systems for Liquids and Slurries, 2012
ASME B31.8 - Gas Transmission and Distribution Piping Systems, 2012
All the above codes list valves as a piping component.
See sections 101.1.1, 300.2, 400.1 & 803.2 respectively
ASME B31.1 - Power Piping, 2014
Listed valves (table 126.1) -
ASME B16.34 - Valves – Flanged, Threaded and Weld End
MSS SP67 - Butterfly Valves
MSS SP68 - High Pressure Butterfly Valves with Offset Design
Note: the list excludes cast iron and bronze valves
107 VALVES
107.1 General
(A) Valves complying with the standards and specifications listed in Table 126.1 shall be used
within the specified pressure–temperature ratings. Unless otherwise required in the individual
standards and specifications listed in Table 126.1, such steel valves shall be pressure tested
in accordance with MSS SP-61.
(B) Valves not complying with (A) above shall be of a design, or equal to the design, that the
manufacturer recommends for the service as stipulated in para. 102.2.2. Such valves shall
be pressure tested in accordance with MSS SP-61.
ASME B31.3 - Process Piping, 2012
Listed valves (table 326.1) -
ASME B16.34 - Valves – Flanged, Threaded and Weld End
MSS SP72 - Ball Valves with Flanged or Butt-Welding Ends
for General Service
API 608 - Metal Ball Valves-Flanged, Threaded and Welding Ends
Note: the list excludes cast iron and bronze valves
307 VALVES AND SPECIALTY COMPONENTS
The following requirements for valves shall also be met as applicable by other pressure
containing piping components, such as traps, strainers, and separators. See also Appendix F,
paras. F301.4 and F307.
307.1 General
307.1.1 Listed Valves. A listed valve is suitable for use in Normal Fluid Service, except as
stated in para. 307.2.
307.1.2 Unlisted Valves. Unlisted valves may be used only in accordance with para. 302.2.3.
Unless pressure–temperature ratings are established by the method set forth in ASME
B16.34, pressure design shall be qualified as required by para. 304.7.2
ASME B31.4 - Pipeline Transportation Systems
for Liquids and Slurries, 2012
Listed valves (table 423.1.1) -
ASME B16.34 - Valves – Flanged, Threaded and Weld End
MSS SP68 - High Pressure Butterfly Valves with Offset Design
MSS SP72 - Ball Valves with Flanged or Butt-Welding Ends
for General Service
API 600 - Steel Gate Valves - Flanged and Butt-welding Ends,
Bolted Bonnets, Twelfth Edition
API 602 - Steel Gate, Globe and Check Valves for Sizes DN 100 and
Smaller for the Petroleum and Natural Gas Industries, 9th Ed
API 603 - Corrosion-resistant, Bolted Bonnet Gate Valves-Flanged
and Butt-welding Ends, Eighth Edition
API 6D - Specification for Pipeline and Piping Valves, 24th Ed
API 6A - Specification for Wellhead and Christmas Tree Equipment
Note: the list excludes cast iron and bronze valves
ASME B31.4 - Pipeline Transportation Systems
for Liquids and Slurries, 2012
404.5 Valves
404.5.1 General. Steel valves conforming to standards
and specifications listed in Tables 423.1-1 and 426.1-1 may be used. These valves
may contain certain cast, malleable, or wrought iron parts as provided for in API 6D.
Cast iron valves conforming to standards and specifications listed in Tables 423.1-1
and 426.1-1 may be used for pressures not to exceed 250 psi (17 bar). Care shall be
exercised to prevent excessive mechanical loading (see para. 404.4.8.3).
Working pressure ratings of the steel parts of steel valves are applicable with the
temperature limitations of -20°F (-30°C) to 250°F (120°C) (see para. 401.2.2.4).
Where resilient, rubber-like, or plastic materials are used for sealing, they shall be
capable of withstanding the fluid, pressure, and temperature specified for the piping
system.
404.5.2 Special Valves. Special valves not listed in Tables 423.1-1 and 426.1-1 shall be
permitted, provided that their design is of at least equal strength and tightness and
they are capable of withstanding the same test requirements as covered in these
standards, and structural features satisfy the material specification and test procedures
of valves in similar service set forth in the listed standards.
ASME B31.8 - Gas Transmission and Distribution
Piping Systems, 2012
Listed valves (table 423.1.1) -
ASME B16.33 - Manually Operated Metallic Gas Valves for Use in Gas Piping
Systems up to 175 psi (Sizes NPS1/2 Through NPS 2)
ASME B16.34 - Valves — Flanged, Threaded, and Welding End
ASME B16.38 - Large Metallic Valves for Gas Distribution: Manually
Operated, NPS 21 .2 (DN 65) to NPS 12 (DN 300),
125 psig (8.6 bar) Maximum
API 6D - Specification for Pipeline and Piping Valves, 24th Ed
API 6A - Specification for Wellhead and Christmas Tree Equipment
Note: the list excludes cast iron and bronze valves
ASME B31.8 - Gas Transmission and Distribution
Piping Systems, 2012
831.1 Valves and Pressure-Reducing Devices
831.1.1 Valves Without Threads. Valves shall conform to standards and
specifications referenced in this Code and shall be used only in accordance
with the service recommendations of the manufacturer.
(a) Valves manufactured in accordance with the following standards may be
used: see previous list.
(b) Valves having shell (body, bonnet, cover, and/or end flange) components
made of cast ductile iron in compliance with ASTM A395 and having
dimensions conforming to ASME B16.1, ASME B16.33, ASME B16.34,
ASME B16.38, ASME B16.40, or API 6D/ISO 14313 may be used at pressures
not exceeding 80% of the pressure ratings for comparable steel valves at their
listed temperature, provided the pressure does not exceed 1,000 psig (6 900
kPa), and welding is not employed on any ductile iron component in the
fabrication of the valve shells or their assembly as part of the piping system.
(c) Valves having shell components made of cast iron shall not be used in gas
piping components for compressor stations.
Federal Codes for Transportation of
Natural and Other Gas by Pipeline
§192.145 Valves.
Link to an amendment published at 80 FR 181, Jan. 5, 2015.
(a) Except for cast iron and plastic valves, each valve must meet the minimum
requirements of API 6D (incorporated by reference, see §192.7), or to a national or
international standard that provides an equivalent performance level. A valve
may not be used under operating conditions that exceed the applicable pressure-
temperature ratings contained in those requirements.
(b) Each cast iron and plastic valve must comply with the following:
(1) The valve must have a maximum service pressure rating for temperatures that
equal or exceed the maximum service temperature.
(2) The valve must be tested as part of the manufacturing, as follows:
(i) With the valve in the fully open position, the shell must be tested with no
leakage to a pressure at least 1.5 times the maximum service rating.
(ii) After the shell test, the seat must be tested to a pressure not less than 1.5
times the maximum service pressure rating. Except for swing check valves, test
pressure during the seat test must be applied successively on each side of the
closed valve with the opposite side open. No visible leakage is permitted.
Federal Codes for Transportation of
Natural and Other Gas by Pipeline
(iii) After the last pressure test is completed, the valve must be operated through its
full travel to demonstrate freedom from interference.
(c) Each valve must be able to meet the anticipated operating conditions.
(d) No valve having shell (body, bonnet, cover, and/or end flange) components
made of ductile iron may be used at pressures exceeding 80 percent of the
pressure ratings for comparable steel valves at their listed temperature. However, a
valve having shell components made of ductile iron may be used at pressures up to
80 percent of the pressure ratings for comparable steel valves at their listed
temperature, if:
(1) The temperature-adjusted service pressure does not exceed 1,000 p.s.i. (7 Mpa)
gage; and
(2) Welding is not used on any ductile iron component in the fabrication of the valve
shells or their assembly.
(e) No valve having shell (body, bonnet, cover, and/or end flange) components
made of cast iron, malleable iron, or ductile iron may be used in the gas pipe
components of compressor stations.
[35 FR 13257, Aug. 19, 1970, as amended by Amdt. 192-62, 54 FR 5628, Feb. 6,
1989; Amdt. 192-85, 63 FR 37502, July 13, 1998; Amdt. 192-94, 69 FR 32894, June
14, 2004; Amdt. 192-114, 75 FR 48603, Aug. 11, 2010]
Federal Codes for Transportation
of Hazardous Liquids by Pipeline
§195.116 Valves.
Link to an amendment published at 80 FR 186, Jan. 5, 2015.
Each valve installed in a pipeline system must comply with the following:
(a) The valve must be of a sound engineering design.
(b) Materials subject to the internal pressure of the pipeline system, including
welded and flanged ends, must be compatible with the pipe or fittings to which
the valve is attached.
(c) Each part of the valve that will be in contact with the carbon dioxide or
hazardous liquid stream must be made of materials that are compatible with
carbon dioxide or each hazardous liquid that it is anticipated will flow through
the pipeline system.
(d) Each valve must be both hydrostatically shell tested and hydrostatically seat
tested without leakage to at least the requirements set forth in Section 11 of API
Standard 6D (incorporated by reference, see §195.3).
(e) Each valve other than a check valve must be equipped with a means for
clearly indicating the position of the valve (open, closed, etc.).
(f) Each valve must be marked on the body or the nameplate, with at least the
following: Not shown in this presentation
ENGINEERED & PROCESS VALVES
Comparison of Valve Standards API 6D vs API 608
12
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Scope
This specification defines the requirements for the
design, manufacturing, assembly, testing, and
documentation of ball, check, gate, and plug valves
for application in pipeline and piping systems for the
petroleum and natural gas industries.
This specification is not applicable to valves for
pressure ratings exceeding Class 2500.
If product is supplied bearing the API Monogram
and manufactured at a facility licensed by API, the
requirements of Annex A applies.
Annexes B, C, D, E, F, G, H, I, J, K, L, M, N, and O
are annexes that are used in order listed.
1.1
This standard specifies the requirements for
metal ball valves suitable for petroleum,
petrochemical and industrial applications that
have flanged ends in sizes NPS 1/2 through
NPS 20 (DN 15 through DN500); butt-welding
ends in sizes NPS 1/2 through NPS 20 (DN 15
through DN 500); socket-welding ends in sizes
NPS 1/4 through NPS 2 (DN 8 through DN 50);
threaded ends in sizes NPS 1/4 through NPS 2
(DN 8 through DN 50).
Corresponding to the nominal pipe sizes in
ASME B36.10M.This standard applies to metal
ball valves with pressure classes as follows;
flanged ends in Classes 150, 300 and 600 (PN
16, 25, 40 and 100);butt-welding ends in
Classes 150, 300 and 600 (PN 16, 25, 40 and
100); socket-welding ends in Classes 150, 300,
600 and 800 (PN 16, 25, 40 and 100); threaded
ends in Classes 150, 300, 600 and 800 (PN 16,
25, 40 and 100).
1
Conformance 1.2
Units of measurement Addressed 1.2.1 Not addressed
Rounding Addressed 1.2.2 Not addressed
Conformance with Specification Addressed 1.3 Not addressed
Processes Requiring Validation Addressed 1.4 Not addressed
ENGINEERED & PROCESS VALVES 13
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Normative references 2 2
Terms, Definitions, Acronyms,
Abbreviations, Symbols, and
Units
3 3
Terms and Definitions 3.1
Acronyms and Abbreviations Addressed 3.2 Not addressed
Symbols and Units Addressed 3.3 Not addressed
Valves types and configurations 4
Valve types Covers Ball, Gate, Check and Plug Valves. Example
of covered valve given (Valve Drawing) 4.1 Covers Ball Valves only (No valve Drawings) 1
Valve configurations
Full-opening valves shall have an internal
minimum cylindrical opening for categorizing
bore size as specified in Table 1. Minimum valve
bore values given, (NPS 0.5 - NPS 60). Obturator
and seat dimensions shall meet Table 1.
For valve not covered in Table 1, the size and
bore shall be by agreement and the manufacture
shall stamp the size and bore on the nameplate.
For Reduced-opening valves:
- valves NPS 4 (DN 100) to NPS 12 (DN 300):
one size below nominal size of valve with bore
according to Table 1,
- valves NPS 14 (DN 350) to NPS 24 (DN 600):
two sizes below nominal size of valve with bore
according to Table 1.
4.2
Flow passageway in this standard categorized
as full bore; single reduced bore and
double reduced bore.
Minimum cylindrical diameter for categorizing
bore size given, (NPS 0.25 - NPS 20)
5.2
ENGINEERED & PROCESS VALVES 14
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Design 5
Design standards and
calculations
In accordance with an internationally recognized
design code: e.g. ASME BPVC, Section VIII,
Division 1 or Division 2; ASME B16.34; EN 12516-
1 or EN 12516-2; and EN 13445-3.
5.1 Meet the requirements of Standard Class valves
per ASME B16.34 5
Wall Thickness Referenced from ASME B16.34 orASME Section
VIII. 5.1 In accordance to requirements of ASME B16.34
5.3.
1
Pressure and temperature rating
In ASME rating class. Pressure-temperature
ratings for class-rated valves is based per ASME
B16.34 and Class 400 valves is based per ASME
B16.5. Covers up to Class 2500 maximum.
NOTE: It is not required that identical material or
material form be used for body and bonnet or
cover parts.
Pressure-temperature ratings are based on
material group of valve's end connection. Where
the valve ends are made from material in two
different groups, the material with the lower
pressure–temperature rating shall govern. Valves
with flanged end(s) shall not be designed to an
intermediate rating due to the risk of the valve
being transferred to a different application, which
may utilize the full flange rating. Manufacturer shall
advise any limits on the design pressures and the
minimum and maximum design temperatures due
to nonmetallic parts.
5.2
Valve rating shall be the lesser of the shell rating
or seat rating. Valve shell rating shall be the rating
for the shell material as listed for Standard Class
in ASME B16.34. Covers up to Class 600 (Class
150, 300, and 600) for flanged and butt-welding
ends, and up to Class 800 (Class 150, 300, 600
and 800) for socket-welding and threaded ends.
1.2,
4
Sizes
International Standard, NPS sizes are stated first
followed by the equivalent DN size between
brackets. Values given up to NPS 60" for class
150-600.
5.3 Nominal Pipe Size covers NPS up to NPS 20" 1.2
ENGINEERED & PROCESS VALVES 15
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Sizes
International Standard, NPS sizes are stated first
followed by the equivalent DN size between
brackets. Values given up to NPS 60" for class
150-600.
5.3 Nominal Pipe Size covers NPS up to NPS 20" 1.2
Ball-stem design and
construction Not addressed Contains Requirements for strength of ball to stem
connection and location of weakest part of stem 5.5
Packing glands and gland
bolting Not addressed
Requires adjustable packing glands 5.7
Face-to-face and End-to-end
Dimensions
Values given, or per ASME B16.10 for valve sizes
not specified. Tolererances of +/- 1.5mm for NPS
10 and smaller. Tolerance of +/- 3.0mm for NPS
12 and larger.
In some cases the support legs on some valve
designs may have to be extended beyond the end-
to-end dimensions to assure that the valve can be
safely supported. These extensions shall be able
to be removed if required after installation.
5.4
Face to face dimensions of flanged valves & end-to-
end dimensions of butt-welding end valves per
ASME B16.10 ball valves—long or short pattern.
End to end dimensions for threaded and socket
welding end valves - per manufacturers standard.
5.3.
2,
5.3.
3
Valve operation
Criteria which determine which type of operator
should be used:
1. Max. pressure differential (MPD)
2. Flow coefficient
3. Breakaway thrust or torque and the
breakaway travel or angle
4. Valve run thrust or torque
5. Max. allowable stem thrust or torque on the
valve
6. Number of turns for manually operated
valves
5.5
Requirements for manual operators - lever type
handles and gear operators - fitted with hand
wheels are stated.
5.8
Pigging Purchaser specify pigging requirements 5.6 Not addressed
ENGINEERED & PROCESS VALVES 16
API 6D INDEX API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Valve ends
Flanged ends
Specified dimensions, tolerances, and finishes, including drilling templates,
flange facing, nut-bearing surfaces (i.e. spot facing and back facing),
outside diameters, and thickness (see Figure 1) shall be in accordance
with:
- ASME B16.5 for sizes up to and including NPS 24 (DN 600) except NPS
22 (DN 550)
- MSS SP-44 for NPS 22 (DN 550)
- ASME B16.47, Series A for NPS 26 (DN 650) and larger sizes
For valves with heavy wall sections, flanges with nut stops in accordance
with Mandatory Appendix 2, Figure 2-4 (Sketch 12 or 12a) of ASME
BPVC, Section VIII, Division 1 may be required.
5.7.1
End flanges & bonnet flanges
- Dimensions and facing finish of end
flanges shall conform to ASME B16.5.
- Shall be cast or forged integral with the
body. Cast or forged flanges attached by
full penetration butt-welding may be used
if agreed to by the purchaser. Flanges
attached by welding -Paragraph 2.1.6
ASME B16.34.
5.3.
8
Welding ends
- Conforms to ASME B31.3, ASME B31.4, or ASME B31.8 5.7.2
Butt-welding ends
- Conforms to ASME B16.25
Socket-welding ends
- Conforms to ASME B16.11, minimum
wall thicknesses shall conform to Table 4
of ASME B16.34
5.3.
5,
5.3.
6
Alternate valve end connections
- specified by purchaser 5.7.3
Threaded ends shall have taper pipe
threads - ASME B1.20.1, minimum wall
thicknesses shall conform to Table 4 of
ASME B16.34
5.3.
7
Valve Cavity
Pressure Relief
Valve cavity relief pressure when added to the valve pressure rating shall
not exceed 133 % of the valve pressure rating at maximum specified
design temperature. To achieve a higher cavity relief pressure, the valve
shell shall be designed and tested to withstand a higher hydrostatic shell
test pressure. If a relief valve fitted to the cavity is required, purchaser may
specify provisions to facilitate in service testing. External cavity relief
valves shall be NPS 1/2 (DN 15) or larger. Cavity relief testing and
functionality may be demonstrated by tests in H.8.2 for trunnion mounted
ball valves and gate valves. Floating ball valve functionality may be
demonstrated by agreement.
5.8 Each valve shall be tested in accordance
with AP1 598 7.3
ENGINEERED & PROCESS VALVES 17
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Drains
Drilled and threaded unless otherwise specified. Tapered
threads shall be capable of providing a seal and comply with
ASME B1.20.1; Parallel threads shall comply with ASME
B1.20.1 or ISO 228-1. Minimum sizes shall be in
accordance with Table 2.
5.9 Drain, bypass or other types of auxiliary
connections - ASME B16.34
5.3.
10
Injection points
For sealant, lubrication, or flushing may be provided for
seats and/or stem. When provided, the injection points shall
incorporate a check valve and a secondary means of
isolation for each injection point. Sealant fittings shall have a
design pressure not less than the greater of the pipeline or
piping valve rated pressure and the injection pressure.
5.10 Not addressed
Drain, vent and sealant lines
• Drain and vent lines shall:
- Have design pressure not less thn the rated pressure of
the valve on which they are installed
- Be capable of withstanding the hydrostatic shell test
pressure of the valve
- Be designed in accordance with a recognized design code
- Be suitable for blow –down operation
• Sealant lines design pressure not less than the greater of
the pipeline valve rated pressure and the injection pressure
5.11 Not addressed
Drain, Vent, and Sealant Valves
• Drain and vent block valves shall have a rated pressure
not less than the valve on which they are installed and be
suitable for blow-down operation.
• Block and check valves fitted to sealant injection lines shall
be rated for the greater of the pipeline valve rated pressure
& the injection pressure defined in 5.10
5.12 Not addressed
ENGINEERED & PROCESS VALVES 18
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Handwheels and
Wrenches — Levers
Max force to apply the breakaway torque or thrust shall not
exceed 360N.
Wrenches shall not longer than twice the face to face/ end to
end dimension.
Handwheel diameter shall not exceed 40in (1065 mm).
Spokes shall not extend beyond the perimeter of the
handwheel.
Direction of closing shall be clockwise.
5.13
Length of lever handle or the gear ratio. Efficiency
and handwheel diameter of gear operators shall be
designed so that required input force to fully open
and close valve shall not exceed 360N when
operating at maximum published torque (5.5.3).
Handwheel on manual gear operators - marked to
indicate the direction of opening and/or closing.
Lever type handles parallel to ball bore (indicates ball
bore position). If round or oval directed mounted
handwheel , means of indicating ball bore position is
included in handwheel design. Direction of closing
shall be clockwise.
5.8.
3,
5.8.
7
Locking Provision
Purchaser specification.Locking devices for check valves shall
be designed to lock valve in open position only. Locking devices
for other types of valve shall be designed to lock the valve in the
open and/or closed position.
5.14
Valves furnished with a lockable device that accepts
a purchaser-supplied padlock - allows the valve to be
locked in both the fully open and fully closed
positions.
Lockable device designed such that a lock with a
5/16-in. (8-mm) diameter shank, not more than 4.0
in. (102 mm) long can be inserted directly through
hole(s) in lockable device and locked.
5.8.
11
Position of the
Obturator
Except for check valve, position of the obturator shall not be
altered by dynamic forces of the passing flow or in the case of
screw operated gate valves by forces generated from internal
pressure.
5.15 Not addressed
Position Indicators
Position indicator shall be in line with the pipeline when the
valve is open and transverse when the valve is closed. Valves
without position stops shall have provision for the verification of
open and closed alignment with the operator/actuator removed.
5.16
An indication of the position of ball bore of the valve
shall be integral with the valve stem. This indication
may be by permanent marking to the top of the stem,
or by shape of exposed stem portion.
5.8.
8
Travel Stops
Provided on valves which do not require mechanical force to
effect a seal and/or operator and they shall be located at the
position of the obturator in the open and closed position.
Guidance for travel stops by valve type provided in Annex D.
5.17
Position stops shall be provided for both fully open
and fully closed positions of valve. Position stops
integral with packing gland, gland flange or gland
bolting shall not be used.
5.8.
5,
5.8.
12
ENGINEERED & PROCESS VALVES 19
API 6D INDEX API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Actuator, Operators,
and Stem Extensions
Output of the actuator shall not exceed the stress limits of the valve
drive train permitted by 5.20.2. Actuator sizing and mounting kits
shall be in accordance with API 6DX. Operators, stem extensions
and their interfaces shall be sealed to prevent ingress of external
contaminants and moisture.
5.18 Not addressed
Lifting
The manufacturer shall determine the need for and verify suitability
of lifting points of the valve. The purchaser shall specify when lifting
points on the valve are not required.
5.19 Not addressed
Drive Trains
Design thrust or torque to be at least 2x breakaway thrust or torque.
Design stresses for tensile stress, shear stress (including torsional
shear stress) and bearing stress shall comply with ASME BPVC,
Section VIII.
Average primary shear stress across a section loaded under design
conditions in pure shear, e.g. keys, shear rings, screw threads, etc.,
shall be limited to 0.6 Sm.
The maximum primary shear under design conditions, exclusive of
stress concentration at the periphery of a solid circular section in
torsion, shall be limited to 0.8 Sm.
The drive train shall be designed such that the weakest component
is outside the pressure boundary.
5.20
The torsional strength of both the stem-to-
ball connection and the portion of the stem
within the pressure boundary (below top of
packing) shall exceed the torsional strength
of the stem portion above the pressure
boundary (above the top of the packing) by
at least 10 %. The stem and the ball-to-stem
connection shall have no occurance of
permanent deformation and failure of any
part when the torque applied is equal to the
greater of:
- 15 ft-lbs (20 N-m), or
- twice the manufacturer’s maximum
published torque.
The manufacturer’s maximum published
torque shall be based upon clean, dry air
service at the maximum differential pressure
rating of the valve.
5.5.
2
Stem Retention
Valves shall be designed to ensure that the stem does not eject
under any internal pressure condition or if the packing gland
components and/or valve operator mounting components are
removed.
5.21
The valve shall be designed to insure that if
a failure occurs at the stem-to-ball
connection or of the stem itself within the
pressure boundary, no portion of the stem is
ejected by internal pressure.
5.5.
1
Fire Type-testing If specified, shall be per one of the following: API 6FA, API 6FD,
API 607, or ISO 10497. 5.22 Per API 607 10
ENGINEERED & PROCESS VALVES 20
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER 2008
Description Sec Description Sec
Antistatic Device
Soft-seated ball, plug, and gate valves shall have an
antistatic device.The electrical resistance between the
obturator and the valve body and between the
stem/shaft and the valve body shall be measured
using a direct-current power source not exceeding 12
V. The resistance shall be measured on dry valves
before pressure testing and shall not exceed 10 ohm.
5.23
Valves shall incorporate an antistatic feature that insures
electrical continuity between the stem and body of valves ≤
NPS 2 and between ball, stem and body of valves > NPS
2. The anti-static feature shall have electrical continuity
across the discharge path with a resistance not exceeding
10 ohms from a power source not exceeding 12VDC when
type tested on a new, dry, as-built valve after open-close
position cycling of the valve at least 5 times.
5.4
End Flange Face
Interruptions Not addressed
Defines the allowable disruptions on the flange gasket
face:
- Ring shaped radial gaps in the faces of end flanges of
flanged ball valves, located in the sealing surface of a
centered ASME B16.20 spiral-wound gasket, shall not
exceed 0.030 in. (0.75 mm); see dimension b on Figure 1.
An example of this condition is the radial gap that exists
between the outer diameter of a body insert and the inner
bore of the body end flange of a valve as shown in Figure
B.1
- For ball valves designed with a body insert as shown in
Figure B.1, with a gasket seating face outer diameter
located within the sealing area of a centered ASME B16.20
spiral-wound gasket, the body insert flange face shall not
protrude beyond the valve body end flange face. The body
insert flange face shall not be recessed below the body
end flange face by more than 0.010 in. (0.25 mm). See
dimension a on Figure 1.
5.9
ENGINEERED & PROCESS VALVES 21
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER
2008
Description Sec Description Sec
Materials 6 6
Material Specification
Issued by the manufacturer and address the following: material
grade; chemical analysis; heat treatment; mechanical properties
(tensile); certification to report all items listed in 6.1.
Other requirements of the material specifications shall be as
follows, if applicable: carbon equivalent (CE); Charpy impacts;
hardness; testing. Pressure containing parts shall be per 5.2.
Guidance on selection of material suppliers is given in Annex E.
6.1
Shell per ASME B16.34. Trim, stem
seals, body seals, and gaskets shall
have properties at least equal or
better than shell material. Threaded
plugs shall have same nominal
composition as shell material. Higher
material grades may be specified by
purchaser.
6
Tensile Test Requirements
Tensile test specimens shall be removed from a test coupon
(TC) after final heat-treatment cycle, and shall be performed per
ASTM A370 or ISO 6892-1. Minimum of one tensile test shall be
performed. All yield strengths shall be determined using 0.2 %
offset method. Results of tensile test(s) shall satisfy the
applicable material specification requirements. Otherwise, two
additional tests on two additional test specimens (removed from
same TC with no additional heat treatment) may be performed.
The result of each of these tests shall satisfy the applicable
requirements.
6.2 Not addressed
Service Compatibility
All process-wetted parts, metallic and non-metallic, and
lubricants shall be suitable for commissioning fluids and service
specified by purchaser. Metallic materials to avoid corrosion and
galling.
Elastomeric materials for valves intended for rapid gas
decompression gas service Class 600 and above to consider
explosive decompression.
6.3 Not addressed
Forged Parts
All forged material(s) shall be formed using a hot-working
practice and heat treatment that produces a forged structure
throughout the material.
6.4 Not addressed
ENGINEERED & PROCESS VALVES 22
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER
2008
Description Sec Description Sec
Materials 6 6
Composition Limits
The chemical composition of carbon steel welding ends shall
meet the following requirements.
- The carbon content shall not exceed 0.23 % by mass.
- The sulfur content shall not exceed 0.020 % by mass.
- The phosphorus content shall not exceed 0.025 % by mass.
- The carbon equivalent (CE) shall not exceed 0.43 %.
6.5 Not addressed
Toughness Test
Requirements
All carbon, alloy steels and non-austenitic stainless steel for
pressure-containing parts with design temperature below -20 °F (-
29 °C) shall be impact-tested using the Charpy V-notch technique
per ASTM A370/ISO 148-1. Striker of 8mm shall be used when
using ISO 148-1. Bolting material tests will meet requirement of
ASTM A320. Impact values for full-size specimens of duplex or
super duplex stainless steels are as follows:
a)average of three specimens: 33 ft lb (45 J) minimum;
b)no single specimen less than 26 ft lb (35 J);
c)Impact test temperature shall be –50 °F (–46 °C).
Requirements for impact test results for full size specimens given
in Table 3.
If a test fails, then a retest of three additional specimens removed
from the same TC, with no additional heat treatment, may be
made, each of which shall exhibit an impact value equal to or
exceeding the required average value.
6.6 Not addressed
Bolting
Carbon/low-alloy steel bolting material with hardness exceeding
HRC 35 (HBW 321) not valid for valve applications with possible
hydrogen embrittlement.
6.7
Bolting shall be intermediate strength
as per ASME B16.5 as a minimum;
pruchaser may specify higher grades
of bolting materials
6.3
Sour Service Shall meet NACE MR0175 or ISO 15156 (all parts) or NACE
MR0103, purchaser to specify the standard to be used. 6.8 Not addressed
ENGINEERED & PROCESS VALVES 23
API 6D INDEX API 6D 24TH EDITION, AUGUST 2014
API 608, 4TH
EDITION,
DECEMBER 2008
Description Sec Description Sec
Materials 6 6
Drain Connections Threaded plugs shall be compatible with the valve body material or made from a corrosion-resistant material. 6.9 Not addressed
Heat-treating Equipment
Qualification
All heat treating of parts and TCs shall be performed with “production-type” equipment. "Production-type" heat-treating equipment shall be
considered equipment that is routinely used to process production parts. All heat treatment for mechanical properties shall be performed
using furnaces calibrated in accordance with Annex F. Post-weld heat treatment (PWHT) shall be performed with heat-treat equipment
meeting the requirements specified by the manufacturer. Furnaces shall be calibrated and surveyed at least annually, records shall be
maintained for a minimum of five years.
6.10 Not addressed
Welding 7
Welding Consumables
Shall conform to the American Welding Society's or manufacturer's specifications. The manufacturer shall have a written procedure for
storage and control of welding consumables. Materials of low-hydrogen type (including electrodes, wires and fluxes) shall be stored and
used as recommended by manufacturer of welding consumables to retain their original low-hydrogen properties.
7.1 Not addressed
Welding Procedure and
Welder/Welding
Operator Qualifications
Welding shall be as per ASME BPVC, Section IX, or ISO 15607, ISO 15609, and ISO 15614-1. Welders and welding operators shall be
qualified per ASME BPVC, Section IX or ISO 9606-1, or EN 287-1. All qualifications documented in PQR. PWHT performed in accordance
with applicable material specification or design code.
Weld overlay shall be as per ASME BPVC, Section IX, Articles II and III or ISO 15614-7. Chemical analysis of the weld metal shall be as
per ASME BPVC, Section IX at the minimum overlay thickness as specified by manufacturer for the finished component. Weld overlay or
clad welding with nickel-based alloy UNS N06625, the thickness chemical composition shall meet one of the classes listed below:
— Class Fe 10: iron mass fraction 10.0 % maximum; or
— Class Fe 5: iron mass fraction 5.0 % maximum, when specified by the purchaser.
For all other composition, the chemical analysis of the weld overlay or clad welding shall conform to the manufacturer’s written specification.
7.2 Not addressed
Impact Testing On valves with design temperature below -29 °C (-20 °F). HAZ testing per ASME BPVC, Section IX or ISO 9606-1, ISO 15607, ISO 15609,
ISO 15614-1, and ISO 15608. Also per ASTM A370 or ISO 148-1 using the Charpy V-notch technique. 7.3 Not addressed
Hardness Testing Hardness testing shall be as per NACE MR0175, ISO 15156 (all parts), or NACE MR0103. Hardness surveys shall be performed on BM,
WM and HAZ per NACE MR0175, ISO 15156 (all parts), or NACE MR0103, 7.4 Not addressed
Repair
Weld repair of forgings and plates shall not be performed to correct material defects, unless otherwise agreed. However, weld repair can be
used to correct machining errors. The weld repair shall be in accordance with the applicable material standard, including any PWHT, if
applicable.
7.5 Not addressed
Repair of welds Shall be performed as per applicable design code or standard listed in 5.1. 7.6 Not addressed
Quality Control 8
NDE Requirements
Final surface (MT and PT) and ultrasonic (UT) shall be conducted after final heat treatment or postweld heat treatment. Final radiography
(RT) shall be conducted after final heat treatment, unless otherwise agreed.
Shall be selected from the list in accordance with Annex G if specified by the purchaser.
8.1 Not addressed
Measuring and Test
Equipment Dimension, pressure, and temperature measuring equiptment specifications are given 8.2 Not addressed
Qualification of
Personnel NDE personnel and welding inspector qualifications are given 8.3 Not addressed
NDE of Repairs Excavated area examined by MT or PT methods in accordance with Annex G. Repair welds examined using the same NDE method that
was used to detect the defect with a minimum of MT or PT. The final NDE activities conducted after post weld heat treatment 8.4 Not addressed
Weld End NDE Acceptance criteria per clauses G.24, G.26, or G.27, 8.5 Not addressed
Visual Inspection of
Castings
Per MSS SP-55 as a minimum, with the following acceptance criteria:
— Type 1: none acceptable;
— Type 2 to 12: A and B only.
8.6 Not addressed
Quality Specification
Levels (QSLs)
Annex J describes the QSLs including specific requirements for NDE, pressure testing, and documentation of the manufacturing process if
specified by the purchaser. 8.7 Not addressed
ENGINEERED & PROCESS VALVES 24
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION,
DECEMBER 2008
Description Sec Description Sec
Pressure Testing 9 7.3
General
Tested with seating/sealing surfaces free from sealant except where sealant is
primary means of sealing. The water temperature shall not be greater than
100 °F (38 °C) during the testing period. Supply pressure shall be isolated
from the valve being tested and shall be stabilized prior to the start of pressure
testing duration. The pressure measuring device shall be installed in the test
apparatus in such a manner that the device continuously monitors/records the
test pressure of the valve assembly.
9.1 Tested according to API
598 7.3
Stem backseat test 1.1 times pressure rating for material at 100 °F (38 °C), no visually detectable
leakage permitted. 9.2 Not addressed
Hydrostatic shell test
1.5 times pressure rating for material at 100 °F (38 °C), no visually detectable
leakage permitted.
When the valve has been designed to withstand a higher hydrostatic shell test
pressure per 5.8, the shell test pressure shall be 1.5 or more times the higher
design pressure at 100 °F (38 °C).
When performing a higher hydrostatic shell test and the valve is flanged, the
hydrostatic shell test shall be performed with bore sealing plugs to ensure the
flanges are not subjected to test pressures greater than 1.5 times the valve
flange rating.
If pipe pups are to be welded to the valve as part of the final assembly, the
pressure rating of the pipe pups may be insufficient for the hydrostatic-shell
test pressure, then the pups shall be welded to the valve following the valve-
shell test and the valve and pup(s) tested at a pressure lower than the
hydrostatic shell test not to exceed the test pressure of the pipe pups.
9.3 Not addressed
Hydrostatic seat test
1.1 times pressure rating for material at 100 °F (38 °C).
Acceptance criteria:
- Soft-seated valves and lubricated plug valves: Per ISO 5208, Rate A (no
visible detectable leakage)
- Metal-seated valves (except check valves): Per ISO 5208, Rate D
- Metal-seated check valves: Per ISO 5208, Rate G
9.4 Not addressed
ENGINEERED & PROCESS VALVES 25
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION, DECEMBER
2008
Description Sec Description Sec
Testing of Drain, Vent, and
Sealant Injection Lines
Subject to hydrostatic test in accordance with 9.3. Lines may be tested
seperately at test pressure in 9.3. The final assembly connection is
subjected to hydrostatic test in 9.3.
9.6 Not addressed
Draining Valves drained/dried/lubricated before shipment where applicable. 9.7
Prior to packaging or shipping, each
valve shall be drained of test fluid,
including draining of the body cavity
area between seats and around ball,
and cavities of “cored balls” if used.
9.1
Coating/Painting
For non-corrosion resistant valves only. Preventative measures shall
be taken to assure no foreign material enters internal cavity of valve.
Corrosion-resistant valves, flange face and actuator mounting flange
sealing surfaces, weld bevel ends, and exposed stems shall not be
coated (refer to Annex L). Corrosion protection shall be provided using
the manufacturer’s documented requirements for flange faces, weld
bevel ends, exposed stems, and internal surfaces of valve.
10
Valves manufactured with shell
materials shown in ASME B16.34
Group 1 shall have lead-free rust
preventative coatings on all
unmachined exterior body surfaces
9.2
Marking
Valves shall be marked in accordance with the requirements of Table
7. Certain criteria may be ommitted if size/shape limits. The nameplate
shall be attached to the valve body; however, based on valve design
the nameplate may be attached to the bonnet/cover or end connector
at the option of the manufacturer. For valves smaller than NPS 2 (DN
50), nameplate may be attached to valve with stainless steel wire, but
may be ommitted only by agreeement. Marking on the body
closure/end connector and bonnet/cover shall be not less than 0.25 in.
(6 mm). The nameplate minimum letter size shall be 0.125 in. (3 mm)
on valves sizes NPS 2 (DN 50) and larger. For all valves NPS 1.5 in
(DN 38) and smaller, the nameplate letter size shall be per the
manufacturer's standard.
11
The identification plate(s) shall be
attached to the valve body by welding
or by pins made from same materials
allowed for identification plate. Per
ASME B16.34. Special markings
required for unidirectional valves.
Shall be marked as "API 608".
8
ENGINEERED & PROCESS VALVES 26
API 6D INDEX
API 6D 24TH EDITION, AUGUST 2014 API 608, 4TH EDITION,
DECEMBER 2008
Description Sec Description Sec
Preparation for Shipment
Plug, ball, and reverse-acting through-conduit gate valves shall be
shipped in the fully open position, unless fitted with a fail-to-close
actuator. Other gate valve types shall be shipped with the gate in the
fully closed position. Check valves NPS 4 (DN 100) and larger shall be
shipped with disc secured or supported. Valves shipped with stem
extensions and without an operating mechanism shall have the annular
space closed and the stem extension secured to the outer housing.
12
Drained of test fluid including
body cavity area between seats
and around ball. If export
packaging is not specified,
package to prevent damage
during shipment. If specified,
shipped in wooden boxes or
crates and packed to prevent
individual valves from moving
9
Documentation
Required documents and conditions specified. A certificate of
conformance to this specification shall be supplied together with the
valves by manufacturer.
13 Not addressed
Facility Requirements 14
Minimum Facility Requirements
for the Assembler Category of
Manufacturing
The assembler (see 3.1.1) shall have on-site equipment and personnel
to perform the required processes needed to produce the products
under the scope of this specification as identified in Table 8.
14.1 Not addressed
Activities Applicable to an
Assembler Facility
The activities for an assembler and applicable locations are given in
Table 8. 14.2 Not addressed
ENGINEERED & PROCESS VALVES 27
Comparison of Valve Standards API 6D vs API 598
NOTE
Per 6.4.3 of API 598: When closure testing gate, plug, and ball valves, a method of testing seat leakage shall be used 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.
Trunnion mounted ball valves cannot be seat tested to API 598 as the cavity is required to be pressurized.
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST 2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
HYDROSTATIC
SHELL TEST
Requirement Required for Gate, Globe, Butterfly, Ball, Check, Gate & Plug
Valves Required for Ball, Check, Gate & Plug Valves
Test Medium Air, inert gas, kerosene, water or non-corrosive liquid (viscosity
≤ water) Fresh water (may contain corrosion inhibitor -
antifreeze)
Temperature Range 41˚F - 122˚F (5˚C - 50˚C) 100˚F (38˚C) (Max)
Test Pressure
For ductile iron and cast iron (Refer to Table 1)
For Steel:
x 1.5 testing pressure as per ASMEB16.34
x 1.5 testing pressure as per ASME B16.34
Test Duration See attached Table 2
Acceptance Criteria No visible leakage through pressure boundary walls & fixed
body joint. No visible leakage permitted.
ENGINEERED & PROCESS VALVES 28
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST 2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
BACKSEAT
TEST
Requirement Applicable for gate and globe valves only. Applicable for valves with backseat features.
Test Medium Air, inert gas, kerosene, water or non-corrosive liquid
(viscosity ≤ water) Fresh water (may contain corossion inhibitor -
antifreeze)
Temperature Range 41˚F - 122˚F (5˚C - 50˚C) 100˚F (38˚C) (Max)
Test Pressure High Pressure: x 1.1 max allowable pressure
Low Pressure: 60 - 100 psig x 1.1 testing pressure as per ASME B16.34
Test Duration See attached Table 2
Notes 'e' and 'f' per tables 1 & 2 are in error as a floating ball or
a butterfly valve cannot be double block bleed.
Acceptance Criteria No visible leakage permitted. No visible leakage permitted.
ENGINEERED & PROCESS VALVES 29
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST
2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
LOW
PRESSURE
CLOSURE
TEST
Test Low Pressure Closure Test Low-pressure Gas Seat Testing
Requirement
Ball
Valve
(Floatin
g or
Trunion)
NPS ≤ 4 & ASME Class ≤ 1500; or
NPS > 4 & ASME Class ≤ 600
NPS ≤ 4 & ASME Class >
1500; or
NPS > 4 & ASME Class >
600
Optional
Floating Trunnion Floating Trunnion
Required Required Required Optional
Gate,
Plug,
Globe,
Check
Valve
NPS ≤ 4 & ASME Class ≤ 1500 or
NPS > 4 & ASME Class ≤ 600
NPS ≤ 4 & ASME Class >
1500 or
NPS > 4 & ASME Class >
600
Required: Gate, Plug
Optional: Globe, Check, Lubricated Plug Optional
ENGINEERED & PROCESS VALVES 30
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST 2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
LOW
PRESSURE
CLOSURE
TEST
Test Medium Air / Inert gas Air / Nitrogen
Temperature Range 41˚F - 122˚F (5˚C - 50˚C) 100˚F (38˚C) (Max)
Test Pressure 60 - 100 psig Type 1 / Type 2 (Pneumatic Test)
Type 1: 5 - 14.5 psig
Type 2: 80 - 100 psig
Test Duration See attached Table 2
Acceptance Criteria Visible leakage through disk, behind seat rings or past shaft
seals is not permitted. (See attached Table 3)
The acceptable leakage rate for low-pressure
gas seat testing shall be:
- Soft-seated: No visible leakage.
- Metal-seated: ISO 5208, Rate D (See attached
Table 4)
ENGINEERED & PROCESS VALVES 31
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST
2014) Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
HIGH
PRESSURE
CLOSURE
TEST
Test High Pressure Closure Test Hydrostatic Seat Test / High-pressure
Gas Seat Testing
Requirement
Ball
Valve
(Floating
or
Trunion)
NPS ≤ 4 & ASME Class ≤ 1500; or
NPS > 4 & ASME Class ≤ 600
NPS ≤ 4 & ASME Class >
1500; or
NPS > 4 & ASME Class >
600
Required: Hydrostatic
Optional: Pneumatic (Gas)
Floating Trunnion Floating Trunnion
Optional (Required: if valves
specified to be double block and
bleed valves.)
Optional
(Required: if
valves
specified to be
double block
and bleed
valves.)
Optional
(Required: if
valves specified
to be double
block and bleed
valves.)
Required
Gate,
Plug,
Globe,
Check
Valve
NPS ≤ 4 & ASME Class ≤ 1500 or
NPS > 4 & ASME Class ≤ 600
NPS ≤ 4 & ASME Class >
1500 or
NPS > 4 & ASME Class >
600
Required: Globe, Check, Lubricated Plug
Optional: Gate, Plug Required
Test Medium Air, inert gas, kerosene, water or non-corrosive liquid (viscosity ≤ water) Hydrostatic: Fresh water (may contain
corrosion inhibitor - antifreeze)
Pneumatic: Inert gas
Temperature Range 41˚F - 122˚F (5˚C - 50˚C) 100˚F (38˚C) (Max)
Test Pressure x 1.1 max allowable pressure at 100˚F x 1.1 testing pressure as per ASME
B16.34
ENGINEERED & PROCESS VALVES 32
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST 2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
HIGH
PRESSURE
CLOSURE
TEST
Test Medium Air, inert gas, kerosene, water or non-corrosive liquid (viscosity ≤
water)
Hydrostatic: Fresh water (may contain corrosion
inhibitor - antifreeze)
Pneumatic: Inert gas
Temperature Range 41˚F - 122˚F (5˚C - 50˚C) 100˚F (38˚C) (Max)
Test Pressure x 1.1 max allowable pressure at 100˚F x 1.1 testing pressure as per ASME B16.34
Test Duration See attached Table 2
Hydrostatic Seat Test:
High-pressure Gas Seat Testing:
ENGINEERED & PROCESS VALVES 33
TEST CRITERIA
API 598 (9th EDITION, SEPTEMBER 2009) API 6D (24th EDITION, AUGUST 2014)
Gate, Globe, Butterfly, Ball, Check, Gate & Plug Valves
(≤ Class 4500) Ball, Check, Gate & Plug Valves
(≤ Class 2500)
HIGH
PRESSURE
CLOSURE
TEST
Acceptance Criteria Visible leakage through disk, behind seat rings or past shaft seals
is not permitted. (See attached Table 3)
Hydrostatic Seat Test:
Soft-seated: No visible leakage
Metal-seated (except check valves): ISO
5208, Rate D (See attached Table 4)
Metal-seated check valves: ISO 5208, Rate
G (See attached Table 4)
High-pressure Gas Seat Testing:
Soft-seated: No visible leakage
Metal-seated (except check valves): ≤ 2x
ISO 5208, Rate D (See attached Table 4)
Metal-seated check valves: ISO 5208, Rate
EE (See attached Table 4)
Additional Seat
Testing Not addressed
1) If the purchaser specifies the
functionality for the valve to be that of
double block and bleed (DBB) valves, the
test described in H.9 shall be performed.
2) If the purchaser specifies the
functionality for the valve to be that of
double isolation and bleed (DIB-1), both
seats bidirectional, the test described in
H.10 shall be performed.
3) If the purchaser specifies the
functionality for the valve to be that of DIB-
2, one seat unidirectional and one seat
bidirectional, the test described in H.11
shall be performed.
ENGINEERED & PROCESS VALVES 34
API 598 Test Tables
Table 1
Table2
ENGINEERED & PROCESS VALVES 35
API 598 Test Tables
Table 3
ENGINEERED & PROCESS VALVES 36
ISO 5208 Table 4
ENGINEERED & PROCESS VALVES 37
Valve Selection Summary-
API 608 for floating ball valves only –
API 608 mandates testing to API 598 and section 6.4.3 does
not allow for testing of a trunnion ball valve.
API 6D for floating & trunnion ball valves, slab & expanding gates,
plug and check valves