PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

7878 NO 3Seat,valve

William E Williams Valve Corp · NSN 4820-01-127-2595 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-127-2595 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-127-2595. Primary manufacturer part number: 7878 NO 3.
Features
  • Seat,valve — FSC 4820
  • Body Inside Diameter: 9.875 INCHES NOMINAL IN
  • Thread Series Designator: UN SINGLE THREADED PORTION
  • Material: STEEL OVERALL
  • Style Designator: PLAIN THREADED
  • Seat Angle in Deg: 60.000 NOMINAL
  • Thread Length: 0.812 INCHES NOMINAL SINGLE THREADED PORTION IN
  • Nominal Thread Size: 11.000 INCHES SINGLE THREADED PORTION 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 4820-01-127-2595, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is William E Williams Valve Corp. Government technical data includes 10 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-127-2595
Primary Part Number7878 NO 3
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerWilliam E Williams Valve Corp
StatusACTIVE
Body Inside Diameter9.875 INCHES NOMINAL IN
Thread Series DesignatorUN SINGLE THREADED PORTION
MaterialSTEEL OVERALL
Style DesignatorPLAIN THREADED
Seat Angle in Deg60.000 NOMINAL
Thread Length0.812 INCHES NOMINAL SINGLE THREADED PORTION IN
Nominal Thread Size11.000 INCHES SINGLE THREADED PORTION IN
Thread Class2A SINGLE THREADED PORTION A
Seating Surface ShapeANGULAR
Thread Quantity Per Inch12 SINGLE THREADED PORTION
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5325-00-276-6089 INTERCHANGEABLE
Grommet,nonmetallic
3120-00-343-25307878 INTERCHANGEABLE
Bearing,sleeve
Cooper Machinery Services Llc
5305-00-477-3268 INTERCHANGEABLE
Setscrew
5950-00-648-6167 INTERCHANGEABLE
Transformer,power
4820-01-124-67827878 ITEM 5 5IN INTERCHANGEABLE
Stem,fluid Valve
William E Williams Valve Corp
4820-01-178-30907878 ITEM 5-2IN INTERCHANGEABLE
Stem,fluid Valve
William E Williams Valve Corp
4820-01-178-70237878 ITEM 3 INTERCHANGEABLE
Seat,valve
William E Williams Valve Corp
4820-01-182-08267878 ITEM 3 4IN INTERCHANGEABLE
Seat,valve
William E Williams Valve Corp
4820-01-182-16897878-6IN INTERCHANGEABLE
Valve,gate
William E Williams Valve Corp
4820-01-184-42787878 ITEM 3 3 IN INTERCHANGEABLE
Seat,valve
William E Williams Valve Corp
Cross-Reference Index
Part NumberManufacturer
7878 William E Williams Valve Corp (USA)
7878 NO 3 PRIMARY William E Williams Valve Corp (USA)
Related Parts
5325-00-276-6089INTERCHANGEABLE
GROMMET,NONMETALLIC
3120-00-343-2530INTERCHANGEABLE
BEARING,SLEEVE
7878
5305-00-477-3268INTERCHANGEABLE
SETSCREW
5950-00-648-6167INTERCHANGEABLE
TRANSFORMER,POWER
4820-01-124-6782INTERCHANGEABLE
STEM,FLUID VALVE
7878 ITEM 5 5IN
4820-01-178-3090INTERCHANGEABLE
STEM,FLUID VALVE
7878 ITEM 5-2IN
4820-01-178-7023INTERCHANGEABLE
SEAT,VALVE
7878 ITEM 3
4820-01-182-0826INTERCHANGEABLE
SEAT,VALVE
7878 ITEM 3 4IN
4820-01-182-1689INTERCHANGEABLE
VALVE,GATE
7878-6IN
4820-01-184-4278INTERCHANGEABLE
SEAT,VALVE
7878 ITEM 3 3 IN
4820-01-210-1393INTERCHANGEABLE
DISK,VALVE
7878 ITEM 2 4IN
4820-01-210-4338INTERCHANGEABLE
STEM,FLUID VALVE
7878 ITEM 5 4IN

Frequently Asked Questions

What is NSN 4820-01-127-2595?

NSN 4820-01-127-2595 is a Seat,valve, manufactured by William E Williams Valve Corp, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-127-2595?

NSN 4820-01-127-2595 has 2 cross-referenced part numbers: 7878 (William E Williams Valve Corp), 7878 NO 3 (William E Williams Valve Corp).

What NSN replaces 4820-01-127-2595?

There are 12 known substitutes for 4820-01-127-2595: 5325-00-276-6089, 3120-00-343-2530, 5305-00-477-3268 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 7878 NO 3?

Key specifications for 7878 NO 3: Body Inside Diameter: 9.875 INCHES NOMINAL IN; Thread Series Designator: UN SINGLE THREADED PORTION; Material: STEEL OVERALL; Style Designator: PLAIN THREADED. 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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