PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

277-1Valve,check

The Walworth Company · NSN 4820-00-203-7173 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-203-7173 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-203-7173. Primary manufacturer part number: 277-1.
Features
  • Valve,check — FSC 4820
  • Material: NICKEL ALLOY SEAT
  • Nominal Thread Size: 1.000 INCHES ALL ENDS IN
  • Material: COPPER ALLOY 922 BODY
  • Style Designator: STRAIGHT THRU
  • Material: NICKEL ALLOY FLOW CONTROL DEVICE
  • Maximum Operating Temp: 550.0 FAHRENHEIT SECOND RESPONSE DEGF
  • Flow Control Device: DISK
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Nickel Alloy Seat construction
General Description

The Valve,check, cataloged under National Stock Number 4820-00-203-7173, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is The Walworth Company. Government technical data includes 30 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 11 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4820-00-203-7173
Primary Part Number277-1
Item NameValve,check
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerThe Walworth Company
StatusCANCELLED
MaterialNICKEL ALLOY SEAT
Nominal Thread Size1.000 INCHES ALL ENDS IN
MaterialCOPPER ALLOY 922 BODY
Style DesignatorSTRAIGHT THRU
MaterialNICKEL ALLOY FLOW CONTROL DEVICE
Maximum Operating Temp550.0 FAHRENHEIT SECOND RESPONSE DEGF
Flow Control DeviceDISK
Valve Operation MethodAUTOMATIC
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Renewable Seat Ring TypeTHREADED
Operating Pressure600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS
Thread Series DesignatorNPT ALL ENDS
Operating Pressure600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS
Media for Which DesignedSTEAM FIRST RESPONSE
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS
Nominal Thread Size1.000 INCHES ALL ENDS IN
Material Document and ClassificationQQ-C-390,ALLOY D4/D/ FED SPEC SINGLE MATERIAL RESPONSE BODY
Style DesignatorSTRAIGHT THRU
MaterialNICKEL ALLOY SEAT
Media for Which DesignedWATER-OIL-GAS SECOND RESPONSE
MaterialNICKEL ALLOY FLOW CONTROL DEVICE
Mounting PositionHORIZONTAL
Nominal Pipe Size Accommodated1.000 INCHES FIRST END IN
Thread Series DesignatorNPT ALL ENDS
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS
Thread DirectionRIGHT-HAND ALL ENDS
Maximum Operating Temp550.0 FAHRENHEIT FIRST RESPONSE DEGF
Media for Which DesignedWATER-OIL-GAS SECOND RESPONSE
Material Document and ClassificationQQ-C-390,ALLOY D4/D/ FED SPEC SINGLE MATERIAL RESPONSE BODY
Media for Which DesignedSTEAM FIRST RESPONSE
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 11
5310-00-276-8631 INTERCHANGEABLE
Nut,plain,hexagon
2990-00-363-599521850 INTERCHANGEABLE
Muffler,exhaust
Walker Mfg Co
6160-00-488-4591 INTERCHANGEABLE
Retainer,battery
5331-00-599-08888321-2 INTERCHANGEABLE
O-Ring
Cummins Inc.
9505-00-651-35322771 INTERCHANGEABLE
Wire,nonelectrical
L3harris Interstate Electronics Corporation
5950-00-686-0513292MS489G1 INTERCHANGEABLE
Transformer,power
Raytheon Company Div Corp
5910-00-724-4170 INTERCHANGEABLE
Capacitor,fixed,electrolytic
4720-00-730-7361 INTERCHANGEABLE
Hose,nonmetallic
4910-00-758-0256 INTERCHANGEABLE
Wheel,press
6625-01-092-8562 INTERCHANGEABLE
Frame Assembly
Cross-Reference Index
Part NumberManufacturer
277-1 PRIMARY The Walworth Company (USA)
962A Jenkins Bros (USA)
DS2161-1-1PC277-1 PRIMARY The Walworth Company (USA)
Related Parts
5310-00-276-8631INTERCHANGEABLE
NUT,PLAIN,HEXAGON
2990-00-363-5995INTERCHANGEABLE
MUFFLER,EXHAUST
21850
6160-00-488-4591INTERCHANGEABLE
RETAINER,BATTERY
5331-00-599-0888INTERCHANGEABLE
O-RING
8321-2
9505-00-651-3532INTERCHANGEABLE
WIRE,NONELECTRICAL
2771
5950-00-686-0513INTERCHANGEABLE
TRANSFORMER,POWER
292MS489G1
5910-00-724-4170INTERCHANGEABLE
CAPACITOR,FIXED,ELECTROLYTIC
4720-00-730-7361INTERCHANGEABLE
HOSE,NONMETALLIC
4910-00-758-0256INTERCHANGEABLE
WHEEL,PRESS
6625-01-092-8562INTERCHANGEABLE
FRAME ASSEMBLY
5305-01-305-1832INTERCHANGEABLE
SCREW,MACHINE
2771

Frequently Asked Questions

What is NSN 4820-00-203-7173?

NSN 4820-00-203-7173 is a Valve,check, manufactured by The Walworth Company, classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-00-203-7173?

NSN 4820-00-203-7173 has 3 cross-referenced part numbers: 277-1 (The Walworth Company), 962A (Jenkins Bros), DS2161-1-1PC277-1 (The Walworth Company).

What NSN replaces 4820-00-203-7173?

There are 11 known substitutes for 4820-00-203-7173: 5310-00-276-8631, 2990-00-363-5995, 6160-00-488-4591 and 8 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 277-1?

Key specifications for 277-1: Material: NICKEL ALLOY SEAT; Nominal Thread Size: 1.000 INCHES ALL ENDS IN; Material: COPPER ALLOY 922 BODY; Style Designator: STRAIGHT THRU. 30 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-00-203-7173 still in active supply?

NSN 4820-00-203-7173 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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