ASTM F1795-00(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1795 −00 (Reapproved 2019) An American National Standard
Standard Specification for
Pressure-Reducing Valves for Air or Nitrogen Systems
This standard is issued under the fixed designation F1795; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3 Military Standards and Specifications:
MIL-STD-167-1 Mechanical Vibrations of Shipboard
1.1 This specification covers the design, construction,
Equipment (Type I—Environmental and Type II—
testing,andoperatingrequirementsforself-containedpressure-
Internally Excited)
reducing valves for air or nitrogen systems.
MIL-STD-740-1 Airborne Sound Measurements andAccep-
1.2 The values stated in SI units are to be regarded as
tance Criteria of Shipboard Equipment
standard. The values given in parentheses are mathematical
MIL-S-901 Shock Tests, H.I. (High-Impact); Shipboard
conversions to inch-pound units that are provided for informa-
Machinery, Equipment and Systems, Requirements for
tion only and are not considered standard.
MIL-F-1183 Fittings, Pipe, Cast Bronze, Silver-Brazing,
1.3 This international standard was developed in accor- General Specifications for
dance with internationally recognized principles on standard-
2.4 Government Drawings:
ization established in the Decision on Principles for the
Naval Sea Systems Command (NAVSEA):
Development of International Standards, Guides and Recom-
NAVSEA 803-1385884 Unions, Fittings and Adapters Butt
mendations issued by the World Trade Organization Technical
and Socket Welding 6000 PSI, WOG, NPS
Barriers to Trade (TBT) Committee.
NAVSEA 803-1385943 Unions, Silver Brazing 3000 PSI,
WOG, NPS, for UT Inspection
2. Referenced Documents
NAVSEA 803-1385946 Unions, Bronze Silver Brazing,
2.1 ASTM Standards:
WOG for UT Inspection
F992 Specification for Valve Label Plates
F1685 Specification for Pressure-Reducing Manifolds for
3. Terminology
Air or Nitrogen Systems
3.1 Definitions:
2.2 American Society of Mechanical Engineers (ASME)
3.1.1 accuracy of regulation, n—the amount by which the
Standards:
downstream pressure may vary when the pressure-reducing
B1.1 Unified Inch Screw Threads (UN and UNR Thread
valve is set at any pressure within the required set pressure
Form)
range and is subjected to any combination of inlet pressure,
B1.20.1 Pipe Threads, General Purpose, Inch
flow demand, and ambient temperature variations within the
B16.11 Forged Fittings, Socket-Welding and Threaded
specified limits.
B16.25 Buttwelding Ends
3.1.2 bubble-sight, n—no visible leakage over a 3-min
B16.34 Valves Flanged, Threaded, and Welding End
period using either water submersion or the application of
bubble fluid for detection.
This specification is under the jurisdiction of ASTM Committee F25 on Ships
3.1.3 external leakage, n—leakage from the pressure-
and Marine Technology and is the direct responsibility of Subcommittee F25.11 on
reducing valve which escapes to atmosphere.
Machinery and Piping Systems.
Current edition approved May 1, 2019. Published June 2019. Originally
3.1.4 fail-open flow capacity, n—the ability of the pressure-
approved in 1997. Last previous edition approved in 2013 as F1795 – 00 (2013).
reducing valve to pass flow under any given set of pressure
DOI: 10.1520/F1795-00R19.
2 conditions when, as a result of mechanical failure, it has
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM assumed a position of least resistance to flow.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Available from American Society of Mechanical Engineers (ASME), ASME
International Headquarters, Two Park Ave., New York, NY 10016-5990, http:// Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
www.asme.org. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1795 − 00 (2019)
3.1.5 flow capacity, n—the ability of the pressure-reducing In this component, the upstream pressure is reduced to the
valve to pass flow under any given set of pressure conditions. desired downstream pressure.
3.1.6 flow rate demand, n—the amount of flow demanded 3.1.13 pressure reversal, n—a condition in which pressure
by the system at any given time downstream of the pressure- exists at the outlet of a pressure-reducing valve when the
reducing valve. loading element is deactivated (set spring adjustment backed
off fully or dome charge vented off completely) and inlet
3.1.7 flow rate demand range, n—the range over which the
pressure is vented off.
flow demand can vary.
3.1.14 seat-tightness,n—theabilityofthepressure-reducing
3.1.8 hydrostatic shell test pressure(s), n—the hydrostatic
valve to prevent leakage from the valve inlet to the valve
test pressures that the inlet and outlet of the pressure-reducing
outlet.
valve is required to withstand without damage. Pressure-
reducing valve operation is not required during application of 3.1.15 self-contained pressure-reducing valve, n—a
shell test pressure, but the pressure-reducing valve must meet pressure-reducing valve that does not use an external power
all performance requirements after the shell test pressure has source, such as compressed air, electricity, or hydraulic fluid
been removed. for operation, but instead uses the line fluid for operation.
3.1.9 inlet operating pressure range, n—the range over 3.1.16 set pressure, n—the outlet pressure delivered by the
which the inlet pressure supplied to the pressure-reducing pressure-reducing valve at the time the pressure setting is
valve can vary under any operational conditions which the made. For the purposes of this specification, it will be assumed
pressure-reducing valve can be subjected to in service. that the setting is made when there is no flow demand on the
pressure-reducing valve (“lock-up” condition), and the
3.1.10 operating pressure(s), n—the pressures within the
pressure-reducingvalveisatsurroundingambienttemperature.
pressure-reducing valve during service.
3.1.17 set pressure range, n—the range of set pressures (set
3.1.11 pressure ratings, n—the pressure ratings of the
pressure limits) over which the pressure-reducing valve can be
pressure-reducing valve shall be as defined in the documents
adjusted while meeting the performance requirements speci-
listed in Table 1. The pressure ratings (also called pressure-
fied.
temperatureratings)establishthemaximumallowableworking
(service) pressures of a component (valve, end connections, 3.1.18 soft-seating insert, n—the insert, incorporated in
and so forth) at various temperatures. For a pressure-reducing either the poppet or the seat of the pressure-reducing valve,
valve, the pressure ratings may not be identical for the valve which ensures bubble-tight seat tightness under all operating
inlet and outlet. conditions.
3.1.12 pressure-reducing valve, n—a component which ac- 3.1.19 valve poppet, n—the part of the pressure-reducing
complishes automatic regulation of the downstream pressure. valve trim which established a rate of flow by moving toward
or away from the valve seat.
4. Classification
TABLE 1 Pressure Ratings for Pressure-Reducing Valve
4.1 Pressure-reducingvalvesshallbeofthefollowingtypes,
Applicable Documents for
sizes, pressure ratings, and end connections, as specified in
Type of End
Pressure Rating Dimensional Details of End
Connection Section 5.
Connections
4.1.1 Types—Pressure-reducingvalvesshallbeeitherTypeI
Butt-welded ASME B16.34 Class ASME B16.25
(inlet outlet end connections of the same pressure rating) or
150, 300, 400,
600, 900, 1500,
Type II (outlet end connection pressure rating lower than the
2500, or 4500
inlet end connection rating) and specified in Section 5.
Socket-welded ASME B16.34 Class ASME B16.11
4.1.2 Sizes—Pressure-reducing valve sizes shall be ⁄8 NPS
150, 300, 400,
1 3 1
600, 900, 1500,
(10.2 mm), ⁄4 NPS (13.5 mm), ⁄8 NPS (17.2 mm), ⁄2 NPS
2500, or 4500
3 1
(21.3 mm), ⁄4 NPS (26.9 mm), 1 NPS (33.7 mm), 1 ⁄4 NPS
Threaded (tapered ASME B16.34 Class ASME B1.20.1 and ASME
pipe thread) 150, 300, 400, B16.11 (42.4 mm), 1 ⁄2 NPS (48.3 mm), and 2 NPS (60.3 mm).
600, 900,
4.1.3 Pressure Ratings—Pressure-reducing valves shall
1500, or 2500
A have pressure rating(s) selected (see 3.1) from Table 1. The
Union end, MIL-F-1183 (O-ring MIL-F-1183 (O-ring type)
2 2
silver-brazed
type) 400 lb/in. 400 lb/in. (2.758 MPa) pressure rating(s) selected shall be specified in Section 5.
(2.758 MPa)
4.1.4 End Connections—Pressure-reducing valves shall
A
Union end, 803-1385946 1500 803-1385946 1500
2 2 have end connections selected from those listed in Table 1 and
silver-brazed
lb/in. (10.342 MPa) lb/in. (10.342 MPa)
A
Union end, 803-1385943 3000 803-1385943 3000
specified in Section 5.
2 2
silver-brazed
lb/in. (20.64 MPa) lb/in. (20.64 MPa)
A
Union end, 803-1385884 6000 803-1385884 6000
5. Ordering Information
2 2
butt/socket weld
lb/in. (41.369 MPa) lb/in. (41.369 MPa)
Other, as specified as specified as specified
5.1 Ordering documentation for pressure-reducing valves
A
For union inlet and outlet end connections, only the pertinent dimensions listed under this specification shall include the following information
intheapplicabledocuments(MilitarySpecificationorNAVSEArequirements)shall
as required to describe the equipment adequately.
apply. The valve shall be supplied with the thread pieces only, without the tall
5.1.1 ASTM designation and year of issue.
pieces and union nuts.
5.1.2 Valve type (see 4.1.1).
F1795 − 00 (2019)
5.1.3 Valve inlet and outlet sizes (see 4.1.2). Spring ends shall be squared and ground. Engagement or
5.1.4 Pressure rating(s) (see 4.1.3). disengagement of parts against spring compression shall not be
permitted.
5.1.5 Type of end connections (see 4.1.4).
5.1.6 Inlet operating pressure range. 6.1.9 Set Point Adjustment—For mechanical spring-loaded
5.1.7 Set pressure and set pressure range, if other than
pressure-reducing valves, the set point shall be adjustable
specified (see 7.1.3). under pressure and shall incorporate right-hand threads so that
5.1.8 Flow rate demand range (see 7.1.1, S1.1.2). a clockwise rotation increases the set pressure. Means shall be
5.1.9 Accuracy of regulation required, if set pressure is used to prevent an accidental or inadvertent change in set
below 10 psig (see 7.1.2). pressure. The option of a tamper-proof set point adjustment
(lead seal, and so forth) shall be available and provided if
5.1.10 Tamper-proof set-point adjustment, if required (see
specified in Section 5. For gas-dome loaded pressure-reducing
6.1.9).
valves, set point adjustment shall be in accordance with 6.1.10.
5.1.11 Supplementary requirements, if any (S1 through S4).
5.1.12 Maximum vibration frequency and displacement 6.1.10 Gas Dome—For gas-dome loaded pressure-reducing
amplitude, if other than specified (see S1.1.4). valves, the set point shall be adjustable under pressure and
shall maintain its charge without adjustment or recharge more
frequently than once a year to remain within its specified
6. Valve Construction
performance envelope. Upstream pressure shall be used to
6.1 Valves shall incorporate the design features specified in
establish dome load. Dome loading shall be accomplished by
6.1.1 – 6.1.19.
two valves installed in series, with a bleed-off valve in-
6.1.1 General Requirements—Pressure-reducing valves
between. If these valves are metal seated, they shall not seat
shall be self-contained, requiring no external power source for
directly into the structure of the dome so that damage or wear
operation. The pressure-reducing valve shall be capable of
to the seating surfaces would not require repair or replacement
meeting all requirements of this specification and provide
of the dome. Only a single dome penetration is allowed. The
extendedreliableoperationwhenprotectedbya5-µmnominal/
valvesshallbeoperablebyastandard-sizehexwrenchorother
18-µm absolute filter installed upstream and when subjected to
suitable means. There shall be no external leakage past the
conditions specified in Section 5.
threads during dome bleeding. Flow from the bleed-off valve
6.1.2 Materials of Construction—Material requirements for
shall be ported in such a way that it does not impinge directly
the pressure-reducing valve shall be as follows: The pressure
on the person making the adjustment, cause excessive noise, or
containing envelope (body, gas dome, or spring housing) shall
potentially lead to ice formation within the dome loading
be 300 series corrosion-resistant steel (304, 304L, 316, or
circuit.
316L). Internal parts including springs, poppets, seal rings, and
6.1.11 Threads—Threads shall be as specified in ASME
retainers shall be 300 series corrosion-resistant steel, nickel-
B1.1. Where necessary, provisions shall be incorporated to
aluminum bronze, nickel-copper (70–30), or bronze. Other
prevent the accidental loosening of threaded parts. The design
materials for both the pressure-containing envelope and inter-
shallbesuchthatstandardwrenchescanbeusedonallexternal
nal parts may be selected to assure compatibility with the line
bolting.Lock-wireshallnotbeused.Anyexposedthreadsshall
medium, weldability, and to provide corrosion resistance
be protected by plastic caps for shipping.
without requiring painting, coating, or plating. Materials for
6.1.12 Accessibility—All internal parts of the pressure-
contacting parts shall be selected to minimize electrolytic
reducing valve shall be accessible for adjustment or service,
corrosion and galling.
without removing the pressure-reducing valve from the line.
6.1.3 PressureEnvelope—Thepressure-reducingvalveshall
6.1.13 Interchangeability—The pressure-reducing valve in-
be designed to pass a hydrostatic shell test at pressure(s) of at
cluding all associated piece parts, shall have part number
least 1.5 times the 100°F (38°C) pressure rating(s) of the valve
identity, and shall be replaceable from stock or the manufac-
without damage.
turer on a nonselective and random basis. Parts having the
6.1.4 Port Configuration—The pressure-reducing valve
samemanufacturer’spartnumbershallbedirectlyinterchange-
shall have in-line inlet and outlet ports.
able with each other with respect to installation (physical) and
6.1.5 Pressure Lines—All pressure lines in the pressure-
performance (function). Physically interchangeable
reducing valve shall be internally ported.
assemblies, components, and parts are those that are capable of
6.1.6 Soft-Seating Insert—A field replaceable soft-seating
being readily installed, removed, or replaced without
insert shall be incorporated in the pressure-reducing valve.
alternation, misalignment or damage to parts being installed or
Soft-seating inserts shall be protected from direct flow
to adjoining parts. Fabrication operations such as cutting,
impingement, excessive loading and extrusion, or any other
filing, drilling, reaming, hammering, bending, prying, or forc-
effectjeopardizingtheirusefullife.Soft-seatinginsertsshallbe
ing shall not be required.
of the simplest practical configuration to facilitate emergency
6.1.14 Nonmetallic Element Interchangeability—
replacement manufacture where necessary.
Nonmetallicelements,includingbutnotlimitedto,soft-seating
6.1.7 Joints—The bonnet or spring housing and bottom cap
inserts, cushions, and O-rings, shall be treated as separately
shall be attached to the body by bolting, a threaded connection,
identified and readily replaceable parts.
or a threaded union connection.
6.1.8 Springs—Any spring incorporated in the pressure- 6.1.15 Maintainability—Maintenance shall require standard
reducing valve shall not be compressed solid during operation. tools to the maximum extent possible. Any special tools
F1795 − 00 (2019)
required for maintenance shall be identified, and shall be 8. Tests Required
supplied as part of the valve.
8.1 Each pressure-reducing valve must pass the tests out-
6.1.16 Reversibility—Seating inserts shall not be physically
lined in 8.1.1 – 8.1.4.
reversible unless they are also functionally reversible to
8.1.1 Visual Examination—The pressure-reducing valve
preclude incorrect assembly.
shall be examined visually to determine conformance with the
6.1.17 Adjustments—There shall be no adjustments required
ordering data, interface dimensions, and workmanship without
in the pressure-reducing valve during or after assembly other
disassembly.
than the set point.
8.1.2 Hydrostatic Shell Test—The pressure-reducing valve
6.1.18 Pressure Reversal—The pressure-reducing valve
shall be hydrostatically tested with water by applying test
shall not be damaged when subjected to a maximum pressure
pressure(s) not less than 1.5 times the 100°F (38°C) pressure
reversal (maximum set pressure exists at the outlet).
rating(s) to the inlet and outlet ports to check structural
6.1.19 Guiding—The valve poppet shall be guided to pre-
integrity. Test pressure(s) shall be applied for 3 min. Air or
vent binding or seizing and ensure proper seating under all
nitrogen may be used in lieu of water, providing appropriate
operating conditions. Proper alignment of all internal operating
safety precautions are taken to minimize the risk associated
parts shall be maintained with interchangeable parts and under
with the use of a compressible fluid. There shall be no external
all tolerance stack-up conditions.
leakage, permanent distortion, or structural failure.
8.1.3 Seal Tightness Test—The pressure-reducing valve
7. Performance Requirements
shall be tested for seat tightness with air or nitrogen gas at an
7.1 Pressure-reducing valves shall meet the performance
inlet test pressure not less than the maximum inlet operating
requirements of 7.1.1 – 7.1.5. pressure. The valve shall be isolated downstream using a
7.1.1 Flow Rate Demand Range—The maximum and mini-
dead-ended volume not exceeding ten diameters of down-
mum flow rate demand required shall be specified (see Section stream pipe and monitored with bubble fluid to assure tight-
5) in standard cubic feet per minute [at 60°F (16°C) and 14.7
ness. There shall be no detectable rise in the outlet pressure
psia (101 kPa)]. The pressure-reducing valve shall meet the over a 3-min period after pressure-reducing valve temperature
specified maximum and minimum flow rate demand
stabilizes.
requirements, or any intermediate flow rate demand 8.1.4 External Leakage Test—Air or nitrogen gas shall be
requirement, and shall operate without hunting or chattering
applied to the inlet of the pressure-reducing valve at the rated
under all specified conditions. pressure. External leakage shall be checked using bubble fluid
7.1.2 Accuracy of Regulation—The pressure-reducing valve
or by submerging the pressure-reducing valve in water. There
shall maintain set pressure within the accuracy of regulation shall be no visible external leakage over a 3-min period.
limits specified in Table 2 under all flow rate demand and inlet
9. Marking
operating pressure conditions specified.
9.1 Identification Plate—An identification plate of
7.1.3 Set Pressure Range—The set pressure range shall be
corrosion-resistant metal in accordance with Specification
as follows: Where the pressure-reducing valve is mechanically
F992,TypesI,II,III,orIVshallbepermanentlyattachedtothe
spring loaded, the set pressure shall be adjustable through a
pressure-reducing valve and shall include the following infor-
rangeofatleast 65 %ofthesetpressure,or 62psi(13.8kPa),
mation (some or all information may instead be stamped or
whichever is greater. Where the pressure-reducing valve is gas
dome loaded, the set point shall be adjustable through a range etched directly on the outside surface of the pressure-reducing
valve):
of at least 625 % of the set pressure or 10 psi (68.9 kPa),
whichever is greater. 9.1.1 Manufacturer’s name.
9.1.2 ASTM designation and year of issue.
7.1.4 Seat Tightness—The pressure-reducing valve shall
meet the seat tightness requirements of8.1.3.Where necessary, 9.1.3 Valve size, t
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