PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

2683Valve,safety Relief

Tactair Fluid Controls Inc · NSN 4820-00-176-4621 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-176-4621 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-176-4621. Primary manufacturer part number: 2683.
Features
  • Valve,safety Relief — FSC 4820
  • Seat Angle: 37.0 DEGREES ALL ENDS
  • Media for Which Designed: FUEL/OIL, HYDROCARBON SECOND RESPONSE
  • Material: ALUMINUM BODY
  • Connection Style: FLARED (TUBE) ALL ENDS
  • Thread Class: 3A ALL ENDS A
  • Adjustable Pressure Range: +3.0 TO 7.0 POUNDS PER SQUARE INCH LBS
  • Valve Operation Method: AUTOMATIC
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Aluminum Body construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-176-4621, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Tactair Fluid Controls Inc. Government technical data includes 26 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 6 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 10 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-176-4621
Primary Part Number2683
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerTactair Fluid Controls Inc
StatusACTIVE
Seat Angle37.0 DEGREES ALL ENDS
Media for Which DesignedFUEL/OIL, HYDROCARBON SECOND RESPONSE
MaterialALUMINUM BODY
Connection StyleFLARED (TUBE) ALL ENDS
Thread Class3A ALL ENDS A
Adjustable Pressure Range+3.0 TO 7.0 POUNDS PER SQUARE INCH LBS
Valve Operation MethodAUTOMATIC
Flow Control DevicePOPPET
Style DesignatorSTRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY.
Thread Series DesignatorUNF ALL ENDS
Operating Pressure30.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Style DesignatorSTRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY.
Seat Angle37.0 DEGREES ALL ENDS
Nominal Thread Size0.438 INCHES ALL ENDS IN
Nominal Outside Diameter Tube Accommodated0.250 INCHES FIRST END IN
MaterialALUMINUM BODY
Media for Which DesignedFUEL/OIL, HYDROCARBON SECOND RESPONSE
Media for Which DesignedAIR FIRST RESPONSE
Operating Pressure30.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Thread DirectionRIGHT-HAND ALL ENDS
Disk Loading MethodSPRING
Connection TypeTHREADED EXTERNAL TUBE ALL ENDS
Thread Series DesignatorUNF ALL ENDS
Adjustable Pressure Range+3.0 TO 7.0 POUNDS PER SQUARE INCH LBS
Nominal Thread Size0.438 INCHES ALL ENDS IN
Nominal Outside Diameter Tube Accommodated0.250 INCHES FIRST END IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 10
3020-00-214-3186 INTERCHANGEABLE
Gear,drive Motion
5305-00-486-16332683 INTERCHANGEABLE
Setscrew
Triumph Engine Control Systems Llc
5310-00-550-1364 INTERCHANGEABLE
Nut,plain,castellated,hexagon
5935-00-824-7588ADT-2683-NF-SMF-02 INTERCHANGEABLE
Adapter,connector
Cinch Connectivity Solutions Inc
2940-01-010-894442683 INTERCHANGEABLE
Filter Element,intake Air Cleane
Wix Corp
5998-01-029-98331203513-4 INTERCHANGEABLE
Circuit Card Assembly
Lockheed Martin Corporation Div Rms - Mitchel Field
5430-01-074-81092683 INTERCHANGEABLE
Tank,liquid Storage
Mag Aerospace Industries, Llc Div Safran Cabins
5310-01-140-78372683 INTERCHANGEABLE
Washer,shouldered
Dialight Corporation
5340-01-203-19802683 INTERCHANGEABLE
Cap-Plug,protective,dust and Moi
Heyco Inc Dba Heyco Products
1005-01-546-39022683 INTERCHANGEABLE
Pad,recoil
U.s. Ordnance
Cross-Reference Index
Part NumberManufacturer
2683 Kaiser Fluid Technologies Inc. (USA)
2683 Hawker Pacific Aerospace Landing Gear and Components Mfg and Repair (USA)
205-062-668-1 Bell Textron Inc (USA)
4P145 Allen Aircraft Products Inc (USA)
2683 PRIMARY Tactair Fluid Controls Inc (USA)
205-062-668-001 Bell Textron Inc (USA)
Related Parts
3020-00-214-3186INTERCHANGEABLE
GEAR,DRIVE MOTION
5305-00-486-1633INTERCHANGEABLE
SETSCREW
2683
5310-00-550-1364INTERCHANGEABLE
NUT,PLAIN,CASTELLATED,HEXAGON
5935-00-824-7588INTERCHANGEABLE
ADAPTER,CONNECTOR
ADT-2683-NF-SMF-02
2940-01-010-8944INTERCHANGEABLE
FILTER ELEMENT,INTAKE AIR CLEANE
42683
5998-01-029-9833INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
1203513-4
5430-01-074-8109INTERCHANGEABLE
TANK,LIQUID STORAGE
2683
5310-01-140-7837INTERCHANGEABLE
WASHER,SHOULDERED
2683
5340-01-203-1980INTERCHANGEABLE
CAP-PLUG,PROTECTIVE,DUST AND MOI
2683
1005-01-546-3902INTERCHANGEABLE
PAD,RECOIL
2683

Frequently Asked Questions

What is NSN 4820-00-176-4621?

NSN 4820-00-176-4621 is a Valve,safety Relief, manufactured by Tactair Fluid Controls Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-176-4621?

NSN 4820-00-176-4621 has 6 cross-referenced part numbers: 2683 (Kaiser Fluid Technologies Inc.), 2683 (Hawker Pacific Aerospace Landing Gear and Components Mfg and Repair), 205-062-668-1 (Bell Textron Inc), 4P145 (Allen Aircraft Products Inc), 2683 (Tactair Fluid Controls Inc) and 1 more.

What NSN replaces 4820-00-176-4621?

There are 10 known substitutes for 4820-00-176-4621: 3020-00-214-3186, 5305-00-486-1633, 5310-00-550-1364 and 7 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 2683?

Key specifications for 2683: Seat Angle: 37.0 DEGREES ALL ENDS; Media for Which Designed: FUEL/OIL, HYDROCARBON SECOND RESPONSE; Material: ALUMINUM BODY; Connection Style: FLARED (TUBE) ALL ENDS. 26 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com