PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

2621-791-01 PIECE 121Tailpiece,union

Electric Boat Corporation Div General Dynamics Electric Boat · NSN 4730-01-148-0021 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-01-148-0021 — this item is cataloged by the U.S. Government under National Stock Number 4730-01-148-0021. Primary manufacturer part number: 2621-791-01 PIECE 121.
Features
  • Tailpiece,union — FSC 4730
  • End Connection Type: WELDED
  • Seat Type: GASKET
  • Union Outside Diameter: 0.500 INCHES NOMINAL IN
  • Material: COPPER ALLOY 715
  • Nominal Pipe Size Designation: 0.500 INCHES IN
  • 7 verified cross-references
  • Primary manufacturer: Electric Boat Corporation Div General Dynamics Electric Boat
Applications
  • Applications requiring Copper Alloy 715 construction
General Description

The Tailpiece,union, cataloged under National Stock Number 4730-01-148-0021, is classified within Federal Supply Class 4730 (No Item Name Available) of the Pipe, Tubing, Hose, and Fittings group. The primary manufacturer of record is Electric Boat Corporation Div General Dynamics Electric Boat. Government technical data includes 5 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 7 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 1 verified substitute exists in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-01-148-0021
Primary Part Number2621-791-01 PIECE 121
Item NameTailpiece,union
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerElectric Boat Corporation Div General Dynamics Electric Boat
StatusACTIVE
End Connection TypeWELDED
Seat TypeGASKET
Union Outside Diameter0.500 INCHES NOMINAL IN
MaterialCOPPER ALLOY 715
Nominal Pipe Size Designation0.500 INCHES IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 1
4730-01-140-4853 INTERCHANGEABLE
Union,pipe
Cross-Reference Index
Part NumberManufacturer
502-4685887 ITEM F23 Naval Ship Systems Command (USA)
2621-791-01 PIECE 121 PRIMARY Electric Boat Corporation Div General Dynamics Electric Boat (USA)
2621-791-01 Electric Boat Corporation Div General Dynamics Electric Boat (USA)
87645-5421 Electric Boat Corporation Div General Dynamics Electric Boat (USA)
502-4685887 F23 Naval Ship Systems Command (USA)
87645-5421 ITEM F23 Electric Boat Corporation Div General Dynamics Electric Boat (USA)
502-4685887 Naval Ship Systems Command (USA)
Related Parts
4730-01-140-4853INTERCHANGEABLE
UNION,PIPE

Frequently Asked Questions

What is NSN 4730-01-148-0021?

NSN 4730-01-148-0021 is a Tailpiece,union, manufactured by Electric Boat Corporation Div General Dynamics Electric Boat, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-01-148-0021?

NSN 4730-01-148-0021 has 7 cross-referenced part numbers: 502-4685887 ITEM F23 (Naval Ship Systems Command), 2621-791-01 PIECE 121 (Electric Boat Corporation Div General Dynamics Electric Boat), 2621-791-01 (Electric Boat Corporation Div General Dynamics Electric Boat), 87645-5421 (Electric Boat Corporation Div General Dynamics Electric Boat), 502-4685887 F23 (Naval Ship Systems Command) and 2 more.

What NSN replaces 4730-01-148-0021?

There is 1 known substitute for 4730-01-148-0021: 4730-01-140-4853. Verify interchangeability with system specifications before substitution.

What are the specifications of 2621-791-01 PIECE 121?

Key specifications for 2621-791-01 PIECE 121: Overall Length: 1.875 INCHES NOMINAL IN; End Connection Type: WELDED; Seat Type: GASKET; Union Outside Diameter: 0.500 INCHES NOMINAL IN. 6 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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