PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

21935Seat,valve

Hydro-Aire Aerospace Corp · NSN 4820-00-091-4261 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-091-4261 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-091-4261. Primary manufacturer part number: 21935.
Features
  • Seat,valve — FSC 4820
  • Seating Surface Shape: FLAT
  • Style Designator: PLAIN FLANGED
  • Flange Diameter: 0.434 INCHES MINIMUM AND 0.435 INCHES MAXIMUM IN
  • Material: STEEL OVERALL
  • Material Document and Classification: MIL-S-7420 COND C MIL SPEC SINGLE MATERIAL RESPONSE OVERALL
  • Flange Seat to Disk End Height: 0.065 INCHES NOMINAL IN
  • Body Inside Diameter: 0.187 INCHES NOMINAL 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 4820-00-091-4261, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Hydro-Aire Aerospace Corp. Government technical data includes 9 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. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-091-4261
Primary Part Number21935
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerHydro-Aire Aerospace Corp
StatusACTIVE
Seating Surface ShapeFLAT
Style DesignatorPLAIN FLANGED
Flange Diameter0.434 INCHES MINIMUM AND 0.435 INCHES MAXIMUM IN
MaterialSTEEL OVERALL
Material Document and ClassificationMIL-S-7420 COND C MIL SPEC SINGLE MATERIAL RESPONSE OVERALL
Flange Seat to Disk End Height0.065 INCHES NOMINAL IN
Body Inside Diameter0.187 INCHES NOMINAL IN
Under Flange Height0.090 INCHES NOMINAL IN
Body Outside Diameter0.324 INCHES MINIMUM AND 0.326 INCHES MAXIMUM IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
5950-00-645-5239219-35 INTERCHANGEABLE
Reactor
L3harris Technologies, Inc. Dba Harris Corporation
5306-00-757-0605219-35 INTERCHANGEABLE
Bolt,ribbed Shoulder
Marmon-Herrington Company
5975-00-869-553721935 INTERCHANGEABLE
Conduit Assembly,metal,rigid
Triumph Controls, Llc Dba Triumph Controls, Llc
5905-00-930-056373098 INTERCHANGEABLE
Resistor,fixed,wire Wound,induct
Electro Scientific Industries Inc
3040-00-943-799021935 INTERCHANGEABLE
Pawl
Hamilton Sundstrand Corporation Dba Collins Aerospace
5998-01-073-6892 INTERCHANGEABLE
Circuit Card Assembly
5915-01-100-5490CFSA1AALAA1AA INTERCHANGEABLE
Filter,low Pass
Arizona Capacitors, Inc
Cross-Reference Index
Part NumberManufacturer
21935 PRIMARY Hydro-Aire Aerospace Corp (USA)
Related Parts
5950-00-645-5239INTERCHANGEABLE
REACTOR
219-35
5306-00-757-0605INTERCHANGEABLE
BOLT,RIBBED SHOULDER
219-35
5975-00-869-5537INTERCHANGEABLE
CONDUIT ASSEMBLY,METAL,RIGID
21935
5905-00-930-0563INTERCHANGEABLE
RESISTOR,FIXED,WIRE WOUND,INDUCT
73098
3040-00-943-7990INTERCHANGEABLE
PAWL
21935
5998-01-073-6892INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
5915-01-100-5490INTERCHANGEABLE
FILTER,LOW PASS
CFSA1AALAA1AA

Frequently Asked Questions

What is NSN 4820-00-091-4261?

NSN 4820-00-091-4261 is a Seat,valve, manufactured by Hydro-Aire Aerospace Corp, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-091-4261?

NSN 4820-00-091-4261 has 1 cross-referenced part number: 21935 (Hydro-Aire Aerospace Corp).

What NSN replaces 4820-00-091-4261?

There are 7 known substitutes for 4820-00-091-4261: 5950-00-645-5239, 5306-00-757-0605, 5975-00-869-5537 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 21935?

Key specifications for 21935: Seating Surface Shape: FLAT; Style Designator: PLAIN FLANGED; Flange Diameter: 0.434 INCHES MINIMUM AND 0.435 INCHES MAXIMUM IN; Material: STEEL OVERALL. 9 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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