PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

CV9-S4501-026-20Seat,valve

Naval Ship Systems Command · NSN 4820-01-251-3123 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-251-3123 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-251-3123. Primary manufacturer part number: CV9-S4501-026-20.
Features
  • Seat,valve — FSC 4820
  • Material: COPPER ALLOY SEAT
  • Thread Series Designator: UNS SINGLE THREADED PORTION
  • Style Designator: PLAIN THREADED
  • Body Inside Diameter: 1.248 INCHES NOMINAL IN
  • Thread Quantity Per Inch: 18 SINGLE THREADED PORTION
  • Nominal Thread Size: 1.747 INCHES SINGLE THREADED PORTION IN
  • Seating Surface Shape: FLAT
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Seat construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-01-251-3123, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Naval Ship Systems Command. Government technical data includes 8 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. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-251-3123
Primary Part NumberCV9-S4501-026-20
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerNaval Ship Systems Command
StatusACTIVE
MaterialCOPPER ALLOY SEAT
Thread Series DesignatorUNS SINGLE THREADED PORTION
Style DesignatorPLAIN THREADED
Body Inside Diameter1.248 INCHES NOMINAL IN
Thread Quantity Per Inch18 SINGLE THREADED PORTION
Nominal Thread Size1.747 INCHES SINGLE THREADED PORTION IN
Seating Surface ShapeFLAT
Thread Length1.060 INCHES NOMINAL SINGLE THREADED PORTION IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4820-01-251-529019871-18 INTERCHANGEABLE
Stem,fluid Valve
Crane Co Div Valve Div
4820-01-251-5322CV9-S4501-026-8 INTERCHANGEABLE
Disk,valve
Naval Ship Systems Command
4820-01-262-8427YB238F223 INTERCHANGEABLE
Valve,safety Relief
Leslie Controls, Inc. Dba Leslie Controls Inc
Cross-Reference Index
Part NumberManufacturer
CV9-S4501-026-20 PRIMARY Naval Ship Systems Command (USA)
CV9-S4501-026 Naval Ship Systems Command (USA)
Related Parts
4820-01-251-5290INTERCHANGEABLE
STEM,FLUID VALVE
19871-18
4820-01-251-5322INTERCHANGEABLE
DISK,VALVE
CV9-S4501-026-8
4820-01-262-8427INTERCHANGEABLE
VALVE,SAFETY RELIEF
YB238F223

Frequently Asked Questions

What is NSN 4820-01-251-3123?

NSN 4820-01-251-3123 is a Seat,valve, manufactured by Naval Ship Systems Command, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-251-3123?

NSN 4820-01-251-3123 has 2 cross-referenced part numbers: CV9-S4501-026-20 (Naval Ship Systems Command), CV9-S4501-026 (Naval Ship Systems Command).

What NSN replaces 4820-01-251-3123?

There are 3 known substitutes for 4820-01-251-3123: 4820-01-251-5290, 4820-01-251-5322, 4820-01-262-8427. Verify interchangeability with system specifications before substitution.

What are the specifications of CV9-S4501-026-20?

Key specifications for CV9-S4501-026-20: Material: COPPER ALLOY SEAT; Thread Series Designator: UNS SINGLE THREADED PORTION; Style Designator: PLAIN THREADED; Body Inside Diameter: 1.248 INCHES NOMINAL IN. 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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