PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

76-S-104 PIECE 4Seat,valve

Derbyshire Machine & Tool Co · NSN 4820-00-036-1985 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-036-1985 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-036-1985. Primary manufacturer part number: 76-S-104 PIECE 4.
Features
  • Seat,valve — FSC 4820
  • Flange Seat to Disk End Height: 0.688 INCHES NOMINAL IN
  • Under Flange Height: 1.875 INCHES NOMINAL IN
  • Thread Length: 0.750 INCHES NOMINAL SINGLE THREADED PORTION IN
  • Thread Quantity Per Inch: 14 SINGLE THREADED PORTION
  • Thread Class: 3A SINGLE THREADED PORTION A
  • Nominal Thread Size: 4.250 INCHES SINGLE THREADED PORTION IN
  • Seat Angle in Deg: 45.000 NOMINAL
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 4820-00-036-1985, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Derbyshire Machine & Tool Co. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 3 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
NSN4820-00-036-1985
Primary Part Number76-S-104 PIECE 4
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerDerbyshire Machine & Tool Co
StatusACTIVE
Flange Seat to Disk End Height0.688 INCHES NOMINAL IN
Under Flange Height1.875 INCHES NOMINAL IN
Thread Length0.750 INCHES NOMINAL SINGLE THREADED PORTION IN
Thread Quantity Per Inch14 SINGLE THREADED PORTION
Thread Class3A SINGLE THREADED PORTION A
Nominal Thread Size4.250 INCHES SINGLE THREADED PORTION IN
Seat Angle in Deg45.000 NOMINAL
Thread Series DesignatorUN SINGLE THREADED PORTION
Style DesignatorTHREADED FLANGED
Flange Diameter4.250 INCHES NOMINAL IN
Seating Surface ShapeANGULAR
MaterialSTEEL OVERALL
Body Inside Diameter3.375 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
5315-00-013-716412Z48PC823 INTERCHANGEABLE
Pin,cotter
Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier
5306-00-453-2808837-57 INTERCHANGEABLE
Bolt
Rolls-Royce Controls and Data Services Limited
2915-00-945-583683757 INTERCHANGEABLE
Follower Assmbly,piston,fuel Con
Triumph Engine Control Systems Llc
5331-01-150-4848AS568-115 MIL-P-5516 CLASS A INTERCHANGEABLE
O-Ring
Spanjer Bros Inc
Cross-Reference Index
Part NumberManufacturer
83757 Ashcroft Inc Dba Heise (USA)
0083757 Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse (USA)
76-S-104 PIECE 4 PRIMARY Derbyshire Machine & Tool Co (USA)
Related Parts
5315-00-013-7164INTERCHANGEABLE
PIN,COTTER
12Z48PC823
5306-00-453-2808INTERCHANGEABLE
BOLT
837-57
2915-00-945-5836INTERCHANGEABLE
FOLLOWER ASSMBLY,PISTON,FUEL CON
83757
5331-01-150-4848INTERCHANGEABLE
O-RING
AS568-115 MIL-P-5516 CLASS A

Frequently Asked Questions

What is NSN 4820-00-036-1985?

NSN 4820-00-036-1985 is a Seat,valve, manufactured by Derbyshire Machine & Tool Co, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-036-1985?

NSN 4820-00-036-1985 has 3 cross-referenced part numbers: 83757 (Ashcroft Inc Dba Heise), 0083757 (Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse), 76-S-104 PIECE 4 (Derbyshire Machine & Tool Co).

What NSN replaces 4820-00-036-1985?

There are 4 known substitutes for 4820-00-036-1985: 5315-00-013-7164, 5306-00-453-2808, 2915-00-945-5836 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 76-S-104 PIECE 4?

Key specifications for 76-S-104 PIECE 4: Flange Seat to Disk End Height: 0.688 INCHES NOMINAL IN; Under Flange Height: 1.875 INCHES NOMINAL IN; Thread Length: 0.750 INCHES NOMINAL SINGLE THREADED PORTION IN; Thread Quantity Per Inch: 14 SINGLE THREADED PORTION. 13 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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