PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

21937Piston,valve

Westerbeke Corporation · NSN 4820-01-145-4083 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-145-4083 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-145-4083. Primary manufacturer part number: 21937.
Features
  • Piston,valve — FSC 4820
  • Outside Diameter: 0.250 INCHES NOMINAL IN
  • Material: STEEL
  • 2 verified cross-references
  • Primary manufacturer: Westerbeke Corporation
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel construction
General Description

The Piston,valve, cataloged under National Stock Number 4820-01-145-4083, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Westerbeke Corporation. Government technical data includes 2 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-145-4083
Primary Part Number21937
Item NamePiston,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerWesterbeke Corporation
StatusACTIVE
Outside Diameter0.250 INCHES NOMINAL IN
MaterialSTEEL
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
4710-00-010-957221937 INTERCHANGEABLE
Tube Assembly,metal
Triumph Controls, Llc Dba Triumph Controls, Llc
4730-00-050-4205AS15001-3P INTERCHANGEABLE
Fitting,lubrication
Sae International Dba Sae International
1650-00-496-209221937-3 INTERCHANGEABLE
Backup,feedback,cylinder
Transdigm Inc
5905-00-497-1067112386-315 INTERCHANGEABLE
Resistor,fixed,wire Wound,induct
Tdk-Lambda Americas Inc. Div High Power Division
5965-01-167-320421937-2 INTERCHANGEABLE
Arm,microphone
Astrocom Electronics Inc
6515-01-304-9763401553 INTERCHANGEABLE
Bag,ostomy
Convatec Inc. Div Convatec
4320-01-330-94987123-15G INTERCHANGEABLE
Piston,pump
Delphi Powertrain Systems, Llc
Cross-Reference Index
Part NumberManufacturer
21937 PRIMARY Westerbeke Corporation (USA)
7123-15G Westerbeke Corporation (USA)
Related Parts
4710-00-010-9572INTERCHANGEABLE
TUBE ASSEMBLY,METAL
21937
4730-00-050-4205INTERCHANGEABLE
FITTING,LUBRICATION
AS15001-3P
1650-00-496-2092INTERCHANGEABLE
BACKUP,FEEDBACK,CYLINDER
21937-3
5905-00-497-1067INTERCHANGEABLE
RESISTOR,FIXED,WIRE WOUND,INDUCT
112386-315
5965-01-167-3204INTERCHANGEABLE
ARM,MICROPHONE
21937-2
6515-01-304-9763INTERCHANGEABLE
BAG,OSTOMY
401553
4320-01-330-9498INTERCHANGEABLE
PISTON,PUMP
7123-15G

Frequently Asked Questions

What is NSN 4820-01-145-4083?

NSN 4820-01-145-4083 is a Piston,valve, manufactured by Westerbeke Corporation, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-145-4083?

NSN 4820-01-145-4083 has 2 cross-referenced part numbers: 21937 (Westerbeke Corporation), 7123-15G (Westerbeke Corporation).

What NSN replaces 4820-01-145-4083?

There are 7 known substitutes for 4820-01-145-4083: 4710-00-010-9572, 4730-00-050-4205, 1650-00-496-2092 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 21937?

Key specifications for 21937: Outside Diameter: 0.250 INCHES NOMINAL IN; Overall Length: 0.325 INCHES NOMINAL IN; Material: STEEL. 3 total characteristics are documented in the Federal Logistics Information System.

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