PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

21537Valve,check

Industrial Technologies and Services Llc · NSN 4820-00-937-5914 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-937-5914 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-937-5914. Primary manufacturer part number: 21537.
Features
  • Valve,check — FSC 4820
  • Bolt Circle Nominal Diameter: 5.937 INCHES SECOND END IN
  • Valve Operation Method: AUTOMATIC
  • Mounting Position: VERTICAL
  • Connection Type: FLANGE SECOND END
  • Connection Type: THREADED INTERNAL PIPE FIRST END
  • Flange Face Design: PLAIN SECOND END
  • Bolt Hole Quantity: 3 SECOND END
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Body construction
General Description

The Valve,check, cataloged under National Stock Number 4820-00-937-5914, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Industrial Technologies and Services Llc. Government technical data includes 19 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4820-00-937-5914
Primary Part Number21537
Item NameValve,check
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerIndustrial Technologies and Services Llc
StatusCANCELLED
Bolt Circle Nominal Diameter5.937 INCHES SECOND END IN
Valve Operation MethodAUTOMATIC
Mounting PositionVERTICAL
Connection TypeFLANGE SECOND END
Connection TypeTHREADED INTERNAL PIPE FIRST END
Flange Face DesignPLAIN SECOND END
Bolt Hole Quantity3 SECOND END
MaterialCOPPER ALLOY BODY
Nominal Outside Diameter6.562 INCHES SECOND END IN
Style DesignatorSTRAIGHT THRU
Nominal Thickness0.235 INCHES SECOND END IN
Thread Series DesignatorNPT FIRST END
Flow Control DevicePOPPET
MaterialCOPPER ALLOY AND RUBBER SYNTHETIC FLOW CONTROL DEVICE
Flange ShapeROUND WITH HOLES SECOND END
Connection StylePLAIN, OPTIONAL END (PIPE) FIRST END
Bolt Hole Nominal Diameter0.188 INCHES SECOND END IN
Thread DirectionRIGHT-HAND FIRST END
Nominal Thread Size1.500 INCHES FIRST END IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
4440-00-008-4864 INTERCHANGEABLE
Sensor Assembly,hum
1450-00-137-6221 INTERCHANGEABLE
Pump,hydraulic,air
5330-00-253-59052-1537 INTERCHANGEABLE
Seal,tub
Maytag Corporation Dba Maytag Appliancessales
1377-00-300-7922 INTERCHANGEABLE
Cutter,cartridge Actuated
5330-00-495-82902125A INTERCHANGEABLE
Gasket
Dana Automotive Systems Group, Llc Dba Dana Sealing Products
3460-00-517-8225 INTERCHANGEABLE
Mandrel,roll
5831-00-522-1563 INTERCHANGEABLE
Mounting
5910-00-686-9120M21-E501MN INTERCHANGEABLE
Capacitor,fixed,mica Dielectric
Viking Technologies, Ltd.
5360-00-903-463921537 INTERCHANGEABLE
Spring,helical,compression
Aerosonic Llc
4720-00-990-167926413 INTERCHANGEABLE
Hose,preformed
Gates Corporation
Cross-Reference Index
Part NumberManufacturer
21537 PRIMARY Industrial Technologies and Services Llc (USA)
M21 Uniflite Inc (USA)
2125A PRIMARY Industrial Technologies and Services Llc (USA)
008469 Uniflite Inc (USA)
2125A Whiting W H Co (USA)
008469-9 Sea Cure Technology, Inc (USA)
008469-9 Uniflite Inc (USA)
266ITEM2 Naval Inventory Control Point Mechanicsburg (USA)
Related Parts
4440-00-008-4864INTERCHANGEABLE
SENSOR ASSEMBLY,HUM
1450-00-137-6221INTERCHANGEABLE
PUMP,HYDRAULIC,AIR
5330-00-253-5905INTERCHANGEABLE
SEAL,TUB
2-1537
1377-00-300-7922INTERCHANGEABLE
CUTTER,CARTRIDGE ACTUATED
5330-00-495-8290INTERCHANGEABLE
GASKET
2125A
3460-00-517-8225INTERCHANGEABLE
MANDREL,ROLL
5831-00-522-1563INTERCHANGEABLE
MOUNTING
5910-00-686-9120INTERCHANGEABLE
CAPACITOR,FIXED,MICA DIELECTRIC
M21-E501MN
5360-00-903-4639INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
21537
4720-00-990-1679INTERCHANGEABLE
HOSE,PREFORMED
26413
6740-00-996-6930INTERCHANGEABLE
PRINTER,CONTACT
6635-01-009-2106INTERCHANGEABLE
MAGNETOMETER

Frequently Asked Questions

What is NSN 4820-00-937-5914?

NSN 4820-00-937-5914 is a Valve,check, manufactured by Industrial Technologies and Services Llc, classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-00-937-5914?

NSN 4820-00-937-5914 has 8 cross-referenced part numbers: 21537 (Industrial Technologies and Services Llc), M21 (Uniflite Inc), 2125A (Industrial Technologies and Services Llc), 008469 (Uniflite Inc), 2125A (Whiting W H Co) and 3 more.

What NSN replaces 4820-00-937-5914?

There are 12 known substitutes for 4820-00-937-5914: 4440-00-008-4864, 1450-00-137-6221, 5330-00-253-5905 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 21537?

Key specifications for 21537: Bolt Circle Nominal Diameter: 5.937 INCHES SECOND END IN; Valve Operation Method: AUTOMATIC; Mounting Position: VERTICAL; Connection Type: FLANGE SECOND END. 19 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-00-937-5914 still in active supply?

NSN 4820-00-937-5914 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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