PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

U537804Valve,modulating,pump Reservoir

Triumph Thermal Systems, Llc · NSN 1660-01-055-9879 · FSC 1660 · No Item Name Available
Verified by PartsTable
NSN 1660-01-055-9879 — this item is cataloged by the U.S. Government under National Stock Number 1660-01-055-9879. Primary manufacturer part number: U537804.
Features
  • Valve,modulating,pump Reservoir — FSC 1660
  • General Characteristics Item Description: CRES 30303 PER QQ-S-764 CL 303,303SE AND 303 PLUS X,FINISH PASSIVATE PER UAP SPEC PS-363,1.476 IN. LG REF,0.5935 IN. MAX 0.5930 IN. MIN DIA,1 HOLE ONE WALL ONLY 0.125 IN. DIA THRU,4 GROOVES 0.569 IN. DIA SPACED 0.062 IN.,SMALL END TAPERED FROM 0.4320 IN. T0 0.2380 IN. DIA IN
  • 2 verified cross-references
  • Primary manufacturer: Triumph Thermal Systems, Llc
Applications
  • Fluid transfer and circulation
  • Cooling system maintenance
  • Industrial process pumping
  • Flow control in piping systems
  • Pressure regulation
General Description

The Valve,modulating,pump Reservoir, cataloged under National Stock Number 1660-01-055-9879, is classified within Federal Supply Class 1660 (No Item Name Available) of the Aircraft Components and Accessories group. The primary manufacturer of record is Triumph Thermal Systems, Llc. Government technical data includes 1 verified specification, 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
NSN1660-01-055-9879
Primary Part NumberU537804
Item NameValve,modulating,pump Reservoir
FSC / FSG1660 / 16 — No Item Name Available
ManufacturerTriumph Thermal Systems, Llc
StatusACTIVE
General Characteristics Item DescriptionCRES 30303 PER QQ-S-764 CL 303,303SE AND 303 PLUS X,FINISH PASSIVATE PER UAP SPEC PS-363,1.476 IN. LG REF,0.5935 IN. MAX 0.5930 IN. MIN DIA,1 HOLE ONE WALL ONLY 0.125 IN. DIA THRU,4 GROOVES 0.569 IN. DIA SPACED 0.062 IN.,SMALL END TAPERED FROM 0.4320 IN. T0 0.2380 IN. DIA IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
5310-00-053-7804 INTERCHANGEABLE
Nut,self-Locking,single Ball Sea
4820-00-652-3317537804 INTERCHANGEABLE
Valve,flow Control
Westinghouse Air Brake Technologies Corp Dba Westinghouse Air Brake Technologies Corp
3110-00-902-1641B-2 1/2 4 INTERCHANGEABLE
Bearing,roller,needle
Jtekt Bearings North America Llc Div Kbna - Ord 1
Cross-Reference Index
Part NumberManufacturer
537804 Triumph Thermal Systems, Llc (USA)
U537804 PRIMARY Triumph Thermal Systems, Llc (USA)
Related Parts
5310-00-053-7804INTERCHANGEABLE
NUT,SELF-LOCKING,SINGLE BALL SEA
4820-00-652-3317INTERCHANGEABLE
VALVE,FLOW CONTROL
537804
3110-00-902-1641INTERCHANGEABLE
BEARING,ROLLER,NEEDLE
B-2 1/2 4

Frequently Asked Questions

What is NSN 1660-01-055-9879?

NSN 1660-01-055-9879 is a Valve,modulating,pump Reservoir, manufactured by Triumph Thermal Systems, Llc, classified under FSC 1660 (No Item Name Available). Status: active.

What are the part numbers for NSN 1660-01-055-9879?

NSN 1660-01-055-9879 has 2 cross-referenced part numbers: 537804 (Triumph Thermal Systems, Llc), U537804 (Triumph Thermal Systems, Llc).

What NSN replaces 1660-01-055-9879?

There are 3 known substitutes for 1660-01-055-9879: 5310-00-053-7804, 4820-00-652-3317, 3110-00-902-1641. Verify interchangeability with system specifications before substitution.

What are the specifications of U537804?

Key specifications for U537804: General Characteristics Item Description: CRES 30303 PER QQ-S-764 CL 303,303SE AND 303 PLUS X,FINISH PASSIVATE PER UAP SPEC PS-363,1.476 IN. LG REF,0.5935 IN. MAX 0.5930 IN. MIN DIA,1 HOLE ONE WALL ONLY 0.125 IN. DIA THRU,4 GROOVES 0.569 IN. DIA SPACED 0.062 IN.,SMALL END TAPERED FROM 0.4320 IN. T0 0.2380 IN. DIA IN; End Item Identification: PUMP P/NUA534121-12 ACFT F/TF15A. 2 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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