PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

14521Seat,valve

Eaton Aerospace Llc Dba Eaton Aerospace Jackson · NSN 4820-00-075-2255 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-075-2255 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-075-2255. Primary manufacturer part number: 14521.
Features
  • Seat,valve — FSC 4820
  • Body Outside Diameter: 0.262 INCHES MINIMUM AND 0.264 INCHES MAXIMUM IN
  • Flange Seat to Disk End Height: 0.200 INCHES MINIMUM AND 0.202 INCHES MAXIMUM IN
  • Body Stepped Inside Diameter: 0.125 INCHES NOMINAL FIRST STEP IN
  • Seating Surface Shape: FLAT
  • Material: STEEL OVERALL
  • Style Designator: PLAIN FLANGED
  • Body Stepped Inside Diameter: 0.094 INCHES MINIMUM AND 0.095 INCHES MAXIMUM SECOND STEP IN
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-00-075-2255, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Eaton Aerospace Llc Dba Eaton Aerospace Jackson. Government technical data includes 11 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-075-2255
Primary Part Number14521
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerEaton Aerospace Llc Dba Eaton Aerospace Jackson
StatusACTIVE
Body Outside Diameter0.262 INCHES MINIMUM AND 0.264 INCHES MAXIMUM IN
Flange Seat to Disk End Height0.200 INCHES MINIMUM AND 0.202 INCHES MAXIMUM IN
Body Stepped Inside Diameter0.125 INCHES NOMINAL FIRST STEP IN
Seating Surface ShapeFLAT
MaterialSTEEL OVERALL
Style DesignatorPLAIN FLANGED
Body Stepped Inside Diameter0.094 INCHES MINIMUM AND 0.095 INCHES MAXIMUM SECOND STEP IN
Hardness Rating25.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM OVERALL
Under Flange Height0.138 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN
Material Document and ClassificationQQ-S-763 CL 416 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Flange Diameter0.371 INCHES MINIMUM AND 0.373 INCHES MAXIMUM IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
3110-00-144-8931 INTERCHANGEABLE
Bearing,ball,annular
5220-01-706-879614521 INTERCHANGEABLE
Gage,headspace
Barrett Firearms Manufacturing, Inc. Dba Barrett Firearms Manufacturing Inc
Cross-Reference Index
Part NumberManufacturer
14521 PRIMARY Eaton Aerospace Llc Dba Eaton Aerospace Jackson (USA)
Related Parts
3110-00-144-8931INTERCHANGEABLE
BEARING,BALL,ANNULAR
5220-01-706-8796INTERCHANGEABLE
GAGE,HEADSPACE
14521

Frequently Asked Questions

What is NSN 4820-00-075-2255?

NSN 4820-00-075-2255 is a Seat,valve, manufactured by Eaton Aerospace Llc Dba Eaton Aerospace Jackson, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-075-2255?

NSN 4820-00-075-2255 has 1 cross-referenced part number: 14521 (Eaton Aerospace Llc Dba Eaton Aerospace Jackson).

What NSN replaces 4820-00-075-2255?

There are 2 known substitutes for 4820-00-075-2255: 3110-00-144-8931, 5220-01-706-8796. Verify interchangeability with system specifications before substitution.

What are the specifications of 14521?

Key specifications for 14521: Body Outside Diameter: 0.262 INCHES MINIMUM AND 0.264 INCHES MAXIMUM IN; Flange Seat to Disk End Height: 0.200 INCHES MINIMUM AND 0.202 INCHES MAXIMUM IN; Body Stepped Inside Diameter: 0.125 INCHES NOMINAL FIRST STEP IN; Seating Surface Shape: FLAT. 11 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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