PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

3251Valve,safety Relief

Tactair Fluid Controls Inc · NSN 4820-00-239-2991 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-239-2991 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-239-2991. Primary manufacturer part number: 3251.
Features
  • Valve,safety Relief — FSC 4820
  • Material: STEEL FLOW CONTROL DEVICE
  • Connection Type: THREADED EXTERNAL TUBE FIRST END
  • Thread Series Designator: UNF FIRST END
  • Nominal Thread Size: 0.750 INCHES FIRST END IN
  • Thread Direction: RIGHT-HAND FIRST END
  • Thread Class: 3A FIRST END A
  • Material: STEEL CORROSION RESISTING BODY
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Flow Control Device construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-239-2991, 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 7 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 5 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: Active.

Technical Specifications
ParameterValue
NSN4820-00-239-2991
Primary Part Number3251
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerTactair Fluid Controls Inc
StatusACTIVE
MaterialSTEEL FLOW CONTROL DEVICE
Connection TypeTHREADED EXTERNAL TUBE FIRST END
Thread Series DesignatorUNF FIRST END
Nominal Thread Size0.750 INCHES FIRST END IN
Thread DirectionRIGHT-HAND FIRST END
Thread Class3A FIRST END A
MaterialSTEEL CORROSION RESISTING BODY
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5342-00-218-5906 INTERCHANGEABLE
Cap,filler Opening
3120-00-378-97173251 INTERCHANGEABLE
Bearing,washer,thrust
Manitowoc Engineering Co Division of the Manitowoc Co Inc
5950-00-393-1514SM-B-78757 INTERCHANGEABLE
Transformer,radio Frequency
Us Army Communications & Electronics Materiel Readiness Command Logistics Engineering Dir
8010-00-431-6213 INTERCHANGEABLE
Remover,paint
3110-00-554-5968 INTERCHANGEABLE
Bearing,ball,annular
3120-00-633-0821204-030-788-1 INTERCHANGEABLE
Roller,linear-Rotary Motion
Bell Textron Inc
5815-00-714-15463251 INTERCHANGEABLE
Rod
Marine Corps Systems Command Div Marine Corps Systems Command Technical Data Repository Customer Service
8010-00-815-2970STRIPPER 11-001GL INTERCHANGEABLE
Remover,paint
Crest Industrial Chemicals Inc
6920-00-894-7381 INTERCHANGEABLE
Drum Assembly
2915-00-985-47493251 INTERCHANGEABLE
Poppet,fuel Nozzle
Collins Engine Nozzles, Inc
Cross-Reference Index
Part NumberManufacturer
3251 Kaiser Fluid Technologies Inc. (USA)
332-2723-010 Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems (USA)
332-2723-010 Rockwell Collins, Inc. Div Collins Aerospace - Mission Systems (USA)
3251 Hawker Pacific Aerospace Landing Gear and Components Mfg and Repair (USA)
3251 PRIMARY Tactair Fluid Controls Inc (USA)
Related Parts
5342-00-218-5906INTERCHANGEABLE
CAP,FILLER OPENING
3120-00-378-9717INTERCHANGEABLE
BEARING,WASHER,THRUST
3251
5950-00-393-1514INTERCHANGEABLE
TRANSFORMER,RADIO FREQUENCY
SM-B-78757
8010-00-431-6213INTERCHANGEABLE
REMOVER,PAINT
3110-00-554-5968INTERCHANGEABLE
BEARING,BALL,ANNULAR
3120-00-633-0821INTERCHANGEABLE
ROLLER,LINEAR-ROTARY MOTION
204-030-788-1
5815-00-714-1546INTERCHANGEABLE
ROD
3251
8010-00-815-2970INTERCHANGEABLE
REMOVER,PAINT
STRIPPER 11-001GL
6920-00-894-7381INTERCHANGEABLE
DRUM ASSEMBLY
2915-00-985-4749INTERCHANGEABLE
POPPET,FUEL NOZZLE
3251
5325-01-079-7431INTERCHANGEABLE
GROMMET,NONMETALLIC
3251
9320-01-083-0463INTERCHANGEABLE
RUBBER SHEET,SOLID

Frequently Asked Questions

What is NSN 4820-00-239-2991?

NSN 4820-00-239-2991 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 4820-00-239-2991?

NSN 4820-00-239-2991 has 5 cross-referenced part numbers: 3251 (Kaiser Fluid Technologies Inc.), 332-2723-010 (Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems), 332-2723-010 (Rockwell Collins, Inc. Div Collins Aerospace - Mission Systems), 3251 (Hawker Pacific Aerospace Landing Gear and Components Mfg and Repair), 3251 (Tactair Fluid Controls Inc).

What NSN replaces 4820-00-239-2991?

There are 12 known substitutes for 4820-00-239-2991: 5342-00-218-5906, 3120-00-378-9717, 5950-00-393-1514 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 3251?

Key specifications for 3251: Material: STEEL FLOW CONTROL DEVICE; Connection Type: THREADED EXTERNAL TUBE FIRST END; Thread Series Designator: UNF FIRST END; Nominal Thread Size: 0.750 INCHES FIRST END IN. 8 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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