PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

SS845-1889587 ASSYC1-2INPC4Seat,valve

Naval Ship Systems Command · NSN 4820-01-073-5849 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-073-5849 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-073-5849. Primary manufacturer part number: SS845-1889587 ASSYC1-2INPC4.
Features
  • Seat,valve — FSC 4820
  • Under Flange Height: 0.316 INCHES NOMINAL IN
  • Nominal Thread Size: 0.766 INCHES SINGLE THREADED PORTION IN
  • Thread Length: 0.222 INCHES NOMINAL SINGLE THREADED PORTION IN
  • Material: NICKEL ALLOY OVERALL
  • Thread Series Designator: UNS SINGLE THREADED PORTION
  • Material Document and Classification: QQ-N-281 CLASS A FED SPEC SINGLE MATERIAL RESPONSE OR QQ-N-281 CLASS B FED SPEC SINGLE MATERIAL RESPONSE OR QQ-N-288 COMP A FED SPEC SINGLE MATERIAL RESPONSE OVERALL
  • Style Designator: THREADED FLANGED
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Nickel Alloy Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-01-073-5849, 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 14 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 7 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4820-01-073-5849
Primary Part NumberSS845-1889587 ASSYC1-2INPC4
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerNaval Ship Systems Command
StatusCANCELLED
Under Flange Height0.316 INCHES NOMINAL IN
Nominal Thread Size0.766 INCHES SINGLE THREADED PORTION IN
Thread Length0.222 INCHES NOMINAL SINGLE THREADED PORTION IN
MaterialNICKEL ALLOY OVERALL
Thread Series DesignatorUNS SINGLE THREADED PORTION
Material Document and ClassificationQQ-N-281 CLASS A FED SPEC SINGLE MATERIAL RESPONSE OR QQ-N-281 CLASS B FED SPEC SINGLE MATERIAL RESPONSE OR QQ-N-288 COMP A FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Style DesignatorTHREADED FLANGED
Body Inside Diameter0.471 INCHES NOMINAL IN
Seating Surface ShapeANGULAR
Thread Quantity Per Inch24 SINGLE THREADED PORTION
Flange Diameter0.937 INCHES NOMINAL IN
Seat Angle in Deg15.000 NOMINAL
Flange Seat to Disk End Height0.122 INCHES NOMINAL IN
Thread Class3A SINGLE THREADED PORTION A
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
4820-00-871-893554386 INTERCHANGEABLE
Seat,valve
The Walworth Company
4820-01-043-36262620-902ASSYCF1 1/2INPC4 INTERCHANGEABLE
Seat,valve
The Walworth Company
4820-01-067-365384094-F-940 INTERCHANGEABLE
Disk,valve
Milwaukee Valve Co, Inc Div Milwaukee Valve Company, Llc
4820-01-071-98955160-B1-380 INTERCHANGEABLE
Seat,valve
Milwaukee Valve Co, Inc Div Milwaukee Valve Company, Llc
4820-01-075-6588803-2177934-X7XX-19 INTERCHANGEABLE
Seat,valve
Naval Ship Systems Command
5310-01-087-7113SS845-1889587PC6 1IN INTERCHANGEABLE
Locknut,disk Valve
Naval Ship Systems Command
4730-01-088-448470030854 INTERCHANGEABLE
Packing Nut
The Walworth Company
4820-01-105-357251163-F-380 INTERCHANGEABLE
Seat,valve
Milwaukee Valve Co, Inc Div Milwaukee Valve Company, Llc
4820-01-113-07832620-902ASSYB PIECE24 1-2IN INTERCHANGEABLE
Cap,valve
Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-114-1400 INTERCHANGEABLE
Seat,valve
Cross-Reference Index
Part NumberManufacturer
SS845-1889587 ASSYC1-2INPC4 PRIMARY Naval Ship Systems Command (USA)
8032177934-X3XX-18 PRIMARY Naval Sea Systems Command (USA)
2620-902 ASSYC1-2INPC4 PRIMARY Electric Boat Corporation Div General Dynamics Electric Boat (USA)
803-2177934-REV.C-3XX-18 Naval Sea Systems Command (USA)
803-2177934 Naval Sea Systems Command (USA)
2620-902 Electric Boat Corporation Div General Dynamics Electric Boat (USA)
SS845-1889587 Naval Ship Systems Command (USA)
Related Parts
4820-00-871-8935INTERCHANGEABLE
SEAT,VALVE
54386
4820-01-043-3626INTERCHANGEABLE
SEAT,VALVE
2620-902ASSYCF1 1/2INPC4
4820-01-067-3653INTERCHANGEABLE
DISK,VALVE
84094-F-940
4820-01-071-9895INTERCHANGEABLE
SEAT,VALVE
5160-B1-380
4820-01-075-6588INTERCHANGEABLE
SEAT,VALVE
803-2177934-X7XX-19
5310-01-087-7113INTERCHANGEABLE
LOCKNUT,DISK VALVE
SS845-1889587PC6 1IN
4730-01-088-4484INTERCHANGEABLE
PACKING NUT
70030854
4820-01-105-3572INTERCHANGEABLE
SEAT,VALVE
51163-F-380
4820-01-113-0783INTERCHANGEABLE
CAP,VALVE
2620-902ASSYB PIECE24 1-2IN
4820-01-114-1400INTERCHANGEABLE
SEAT,VALVE
4820-01-117-9670INTERCHANGEABLE
DISK,VALVE
2620-902-ASSYB PC 27
4820-01-118-0381INTERCHANGEABLE
VALVE,ANGLE
803-2177934-C626AF

Frequently Asked Questions

What is NSN 4820-01-073-5849?

NSN 4820-01-073-5849 is a Seat,valve, manufactured by Naval Ship Systems Command, classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-01-073-5849?

NSN 4820-01-073-5849 has 7 cross-referenced part numbers: SS845-1889587 ASSYC1-2INPC4 (Naval Ship Systems Command), 8032177934-X3XX-18 (Naval Sea Systems Command), 2620-902 ASSYC1-2INPC4 (Electric Boat Corporation Div General Dynamics Electric Boat), 803-2177934-REV.C-3XX-18 (Naval Sea Systems Command), 803-2177934 (Naval Sea Systems Command) and 2 more.

What NSN replaces 4820-01-073-5849?

There are 12 known substitutes for 4820-01-073-5849: 4820-00-871-8935, 4820-01-043-3626, 4820-01-067-3653 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of SS845-1889587 ASSYC1-2INPC4?

Key specifications for SS845-1889587 ASSYC1-2INPC4: Under Flange Height: 0.316 INCHES NOMINAL IN; Nominal Thread Size: 0.766 INCHES SINGLE THREADED PORTION IN; Thread Length: 0.222 INCHES NOMINAL SINGLE THREADED PORTION IN; Material: NICKEL ALLOY OVERALL. 14 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-01-073-5849 still in active supply?

NSN 4820-01-073-5849 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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