PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

73811-13 PC.4 4INCHSeat,valve

Velan Valve Corp. · NSN 4820-01-303-1258 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-303-1258 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-303-1258. Primary manufacturer part number: 73811-13 PC.4 4INCH.
Features
  • Seat,valve — FSC 4820
  • Material: STEEL OVERALL
  • Style Designator: PLAIN
  • Body Inside Diameter: 4.000 INCHES NOMINAL IN
  • 4 verified cross-references
  • Primary manufacturer: Velan Valve Corp.
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 4820-01-303-1258, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Velan Valve Corp.. Government technical data includes 3 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references 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
NSN4820-01-303-1258
Primary Part Number73811-13 PC.4 4INCH
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerVelan Valve Corp.
StatusACTIVE
MaterialSTEEL OVERALL
Style DesignatorPLAIN
Body Inside Diameter4.000 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
5120-01-016-8839 INTERCHANGEABLE
Screwdriver,flat Tip
5305-01-493-221492210A583 INTERCHANGEABLE
Screw,cap,socket Head
Mcmaster-Carr Supply Co
Cross-Reference Index
Part NumberManufacturer
73908 PIECE 3 4IN Velan Valve Corp. (USA)
73811-13 PC.4 4INCH PRIMARY Velan Valve Corp. (USA)
73908 Velan Valve Corp. (USA)
73908 PIECE 3 4 Velan Valve Corp. (USA)
Related Parts
5120-01-016-8839INTERCHANGEABLE
SCREWDRIVER,FLAT TIP
5305-01-493-2214INTERCHANGEABLE
SCREW,CAP,SOCKET HEAD
92210A583

Frequently Asked Questions

What is NSN 4820-01-303-1258?

NSN 4820-01-303-1258 is a Seat,valve, manufactured by Velan Valve Corp., classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-303-1258?

NSN 4820-01-303-1258 has 4 cross-referenced part numbers: 73908 PIECE 3 4IN (Velan Valve Corp.), 73811-13 PC.4 4INCH (Velan Valve Corp.), 73908 (Velan Valve Corp.), 73908 PIECE 3 4 (Velan Valve Corp.).

What NSN replaces 4820-01-303-1258?

There are 2 known substitutes for 4820-01-303-1258: 5120-01-016-8839, 5305-01-493-2214. Verify interchangeability with system specifications before substitution.

What are the specifications of 73811-13 PC.4 4INCH?

Key specifications for 73811-13 PC.4 4INCH: Material: STEEL OVERALL; Style Designator: PLAIN; Body Inside Diameter: 4.000 INCHES NOMINAL IN. 3 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com