PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

20617Seat,valve

Ashcroft Inc Dba Heise · NSN 4820-00-393-4334 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-393-4334 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-393-4334. Primary manufacturer part number: 20617.
Features
  • Seat,valve — FSC 4820
  • Flange Seat to Disk End Height: 0.798 INCHES NOMINAL IN
  • Body Inside Diameter: 2.625 INCHES NOMINAL IN
  • Thread Series Designator: UNS SINGLE THREADED PORTION
  • Style Designator: THREADED FLANGED
  • Flange Diameter: 3.245 INCHES NOMINAL IN
  • Seat Angle in Deg: 45.000 NOMINAL
  • Material: COPPER ALLOY OVERALL
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-00-393-4334, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Ashcroft Inc Dba Heise. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 8 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-393-4334
Primary Part Number20617
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerAshcroft Inc Dba Heise
StatusACTIVE
Flange Seat to Disk End Height0.798 INCHES NOMINAL IN
Body Inside Diameter2.625 INCHES NOMINAL IN
Thread Series DesignatorUNS SINGLE THREADED PORTION
Style DesignatorTHREADED FLANGED
Flange Diameter3.245 INCHES NOMINAL IN
Seat Angle in Deg45.000 NOMINAL
MaterialCOPPER ALLOY OVERALL
Thread Class2A SINGLE THREADED PORTION A
Seating Surface ShapeANGULAR
Under Flange Height0.880 INCHES NOMINAL IN
Nominal Thread Size2.875 INCHES SINGLE THREADED PORTION IN
Thread Length0.612 INCHES NOMINAL SINGLE THREADED PORTION IN
Thread Quantity Per Inch18 SINGLE THREADED PORTION
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 8
5355-00-093-6650 INTERCHANGEABLE
Knob Assembly
5330-00-256-698717592 INTERCHANGEABLE
Gasket
Dana Automotive Systems Group, Llc Dba Dana Sealing Products
5962-00-365-5728 INTERCHANGEABLE
Microcircuit,digital
5935-00-549-1923 INTERCHANGEABLE
Connector,receptacle,electrical
3120-00-732-21161759-2 INTERCHANGEABLE
Bearing,washer,thrust
Eaton Aerospace, Llc Dba Jackson South
4310-00-854-4265 INTERCHANGEABLE
Strainer Assembly O
4720-01-144-342120617 INTERCHANGEABLE
Hose Assembly,nonmetallic
Alliance Laundry Systems Llc
6695-01-303-4396 INTERCHANGEABLE
Panel,indicator
Cross-Reference Index
Part NumberManufacturer
20617 PRIMARY Ashcroft Inc Dba Heise (USA)
17592 PRIMARY Ashcroft Inc Dba Heise (USA)
R6180ZPC1A PRIMARY Ashcroft Inc Dba Heise (USA)
Related Parts
5355-00-093-6650INTERCHANGEABLE
KNOB ASSEMBLY
5330-00-256-6987INTERCHANGEABLE
GASKET
17592
5962-00-365-5728INTERCHANGEABLE
MICROCIRCUIT,DIGITAL
5935-00-549-1923INTERCHANGEABLE
CONNECTOR,RECEPTACLE,ELECTRICAL
3120-00-732-2116INTERCHANGEABLE
BEARING,WASHER,THRUST
1759-2
4310-00-854-4265INTERCHANGEABLE
STRAINER ASSEMBLY O
4720-01-144-3421INTERCHANGEABLE
HOSE ASSEMBLY,NONMETALLIC
20617
6695-01-303-4396INTERCHANGEABLE
PANEL,INDICATOR

Frequently Asked Questions

What is NSN 4820-00-393-4334?

NSN 4820-00-393-4334 is a Seat,valve, manufactured by Ashcroft Inc Dba Heise, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-393-4334?

NSN 4820-00-393-4334 has 3 cross-referenced part numbers: 20617 (Ashcroft Inc Dba Heise), 17592 (Ashcroft Inc Dba Heise), R6180ZPC1A (Ashcroft Inc Dba Heise).

What NSN replaces 4820-00-393-4334?

There are 8 known substitutes for 4820-00-393-4334: 5355-00-093-6650, 5330-00-256-6987, 5962-00-365-5728 and 5 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 20617?

Key specifications for 20617: Flange Seat to Disk End Height: 0.798 INCHES NOMINAL IN; Body Inside Diameter: 2.625 INCHES NOMINAL IN; Thread Series Designator: UNS SINGLE THREADED PORTION; Style Designator: THREADED FLANGED. 13 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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