PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

42576Seat,valve

Woodward Hrt Inc · NSN 4820-00-975-7128 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-975-7128 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-975-7128. Primary manufacturer part number: 42576.
Features
  • Seat,valve — FSC 4820
  • Seating Surface Shape: ANGULAR
  • Seat Angle in Deg: 90.000 NOMINAL
  • Flange Diameter: 0.434 INCHES MINIMUM AND 0.436 INCHES MAXIMUM IN
  • Body Outside Diameter: 0.248 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN
  • Surface Treatment: PASSIVATE OVERALL
  • Under Flange Height: 0.145 INCHES MINIMUM AND 0.155 INCHES MAXIMUM IN
  • Body Stepped Inside Diameter: 0.124 INCHES MINIMUM AND 0.126 INCHES MAXIMUM FIRST STEP IN
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Corrosion Resisting Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-00-975-7128, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Woodward Hrt Inc. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-975-7128
Primary Part Number42576
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerWoodward Hrt Inc
StatusACTIVE
Seating Surface ShapeANGULAR
Seat Angle in Deg90.000 NOMINAL
Flange Diameter0.434 INCHES MINIMUM AND 0.436 INCHES MAXIMUM IN
Body Outside Diameter0.248 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN
Surface TreatmentPASSIVATE OVERALL
Under Flange Height0.145 INCHES MINIMUM AND 0.155 INCHES MAXIMUM IN
Body Stepped Inside Diameter0.124 INCHES MINIMUM AND 0.126 INCHES MAXIMUM FIRST STEP IN
Hardness Rating58.0 ROCKWELL C MINIMUM AND 60.0 ROCKWELL C MAXIMUM OVERALL
Body Stepped Inside Diameter0.250 INCHES NOMINAL SECOND STEP IN
MaterialSTEEL CORROSION RESISTING OVERALL
Material Document and ClassificationQQ-S-763,CLASS 440C FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Flange Seat to Disk End Height0.095 INCHES MINIMUM AND 0.105 INCHES MAXIMUM IN
Style DesignatorPLAIN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
5330-00-179-091048894 INTERCHANGEABLE
Seal,plain Encased
Dana Automotive Systems Group, Llc Dba Dana Sealing Products
4920-00-838-6265 INTERCHANGEABLE
Network Module Assy
5950-01-019-5303 INTERCHANGEABLE
Transformer,audio Frequency
3040-01-314-2556369760PC1 INTERCHANGEABLE
Shaft,shouldered
Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier
Cross-Reference Index
Part NumberManufacturer
975-7128 Marine Diesel, Inc. Dba Marine Diesel (USA)
42576 PRIMARY Woodward Hrt Inc (USA)
Related Parts
5330-00-179-0910INTERCHANGEABLE
SEAL,PLAIN ENCASED
48894
4920-00-838-6265INTERCHANGEABLE
NETWORK MODULE ASSY
5950-01-019-5303INTERCHANGEABLE
TRANSFORMER,AUDIO FREQUENCY
3040-01-314-2556INTERCHANGEABLE
SHAFT,SHOULDERED
369760PC1

Frequently Asked Questions

What is NSN 4820-00-975-7128?

NSN 4820-00-975-7128 is a Seat,valve, manufactured by Woodward Hrt Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-975-7128?

NSN 4820-00-975-7128 has 2 cross-referenced part numbers: 975-7128 (Marine Diesel, Inc. Dba Marine Diesel), 42576 (Woodward Hrt Inc).

What NSN replaces 4820-00-975-7128?

There are 4 known substitutes for 4820-00-975-7128: 5330-00-179-0910, 4920-00-838-6265, 5950-01-019-5303 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 42576?

Key specifications for 42576: Seating Surface Shape: ANGULAR; Seat Angle in Deg: 90.000 NOMINAL; Flange Diameter: 0.434 INCHES MINIMUM AND 0.436 INCHES MAXIMUM IN; Body Outside Diameter: 0.248 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN. 14 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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