PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

40555Valve,regulating,fluid Pressure

Trac Regulator Co., Inc. Dba Trac Regulator Co Inc · NSN 4820-01-250-7178 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-250-7178 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-250-7178. Primary manufacturer part number: 40555.
Features
  • Valve,regulating,fluid Pressure — FSC 4820
  • First End Flange Shape Style: ROUND W/ BOLT HOLES
  • Second End Relationship with First End: IDENTICAL
  • Regulation Type: MANUAL SINGLE STAGE
  • First End Flange Outside Diameter: 3.500 INCHES NOMINAL IN
  • Body Style: STRAIGHT THRU
  • Material Document and Classification: QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE STEM
  • Material: NICKEL ALLOY STEM
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Nickel Alloy Stem construction
General Description

The Valve,regulating,fluid Pressure, cataloged under National Stock Number 4820-01-250-7178, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Trac Regulator Co., Inc. Dba Trac Regulator Co Inc. Government technical data includes 25 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference 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
NSN4820-01-250-7178
Primary Part Number40555
Item NameValve,regulating,fluid Pressure
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerTrac Regulator Co., Inc. Dba Trac Regulator Co Inc
StatusACTIVE
First End Flange Shape StyleROUND W/ BOLT HOLES
Second End Relationship with First EndIDENTICAL
Regulation TypeMANUAL SINGLE STAGE
First End Flange Outside Diameter3.500 INCHES NOMINAL IN
Body StyleSTRAIGHT THRU
Material Document and ClassificationQQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE STEM
MaterialNICKEL ALLOY STEM
MaterialNICKEL ALLOY FLOW CONTROL DEVICE
Material Document and ClassificationMIL-B-16541 MIL SPEC SINGLE MATERIAL RESPONSE LOCATION NOT OTHERWISE SPECIFIED
Material Document and ClassificationQQ-N-288 FED SPEC SINGLE MATERIAL RESPONSE SEAT
Material Document and ClassificationQQ-N-288 FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE
Flow Control DeviceDISK
End Connection Quantity2
FilterNOT INCLUDED
First End Bolt Hole Quantity4
Valve Loading MethodSPRING
First End Style DesignatorPLAIN
First End Bolt Hole Diameter0.625 INCHES NOMINAL IN
Manual Control MethodWHEEL
First End Connection TypePLAIN FACE FLANGE
First End Flange Thickness0.312 INCHES NOMINAL IN
MaterialNICKEL ALLOY AND COPPER ALLOY SEAT
Media for Which DesignedWATER, FRESH
Face to Face Distance6.562 INCHES NOMINAL IN
First End Bolt Circle Diameter2.375 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 8
5961-00-077-2119 INTERCHANGEABLE
Semiconductor Device,thyristor
5330-00-385-322324863 INTERCHANGEABLE
Seal,plain Encased
Skf Usa Inc. Dba Skf Aerospace Sealing Solutions
5950-00-438-6707902C2010-01-020 INTERCHANGEABLE
Transformer,power
Ge Aviation Systems Llc Dba Ge Aviation Div Information Systems - Germantown
3455-00-517-53661-1561-1250 INTERCHANGEABLE
Cutter,milling,woodruff Keyseat
New York Twist Drill Inc
5330-00-679-1392 INTERCHANGEABLE
Gasket
5962-01-038-196740555 INTERCHANGEABLE
Microcircuit,digital
Raytheon Company Div Rmd Strategic
6350-01-223-3392 INTERCHANGEABLE
Horn,signal
2990-01-272-054140555 INTERCHANGEABLE
Pipe,exhaust
Walker Mfg Co
Cross-Reference Index
Part NumberManufacturer
40555 PRIMARY Trac Regulator Co., Inc. Dba Trac Regulator Co Inc (USA)
Related Parts
5961-00-077-2119INTERCHANGEABLE
SEMICONDUCTOR DEVICE,THYRISTOR
5330-00-385-3223INTERCHANGEABLE
SEAL,PLAIN ENCASED
24863
5950-00-438-6707INTERCHANGEABLE
TRANSFORMER,POWER
902C2010-01-020
3455-00-517-5366INTERCHANGEABLE
CUTTER,MILLING,WOODRUFF KEYSEAT
1-1561-1250
5330-00-679-1392INTERCHANGEABLE
GASKET
5962-01-038-1967INTERCHANGEABLE
MICROCIRCUIT,DIGITAL
40555
6350-01-223-3392INTERCHANGEABLE
HORN,SIGNAL
2990-01-272-0541INTERCHANGEABLE
PIPE,EXHAUST
40555

Frequently Asked Questions

What is NSN 4820-01-250-7178?

NSN 4820-01-250-7178 is a Valve,regulating,fluid Pressure, manufactured by Trac Regulator Co., Inc. Dba Trac Regulator Co Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-250-7178?

NSN 4820-01-250-7178 has 1 cross-referenced part number: 40555 (Trac Regulator Co., Inc. Dba Trac Regulator Co Inc).

What NSN replaces 4820-01-250-7178?

There are 8 known substitutes for 4820-01-250-7178: 5961-00-077-2119, 5330-00-385-3223, 5950-00-438-6707 and 5 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 40555?

Key specifications for 40555: First End Flange Shape Style: ROUND W/ BOLT HOLES; Second End Relationship with First End: IDENTICAL; Regulation Type: MANUAL SINGLE STAGE; First End Flange Outside Diameter: 3.500 INCHES NOMINAL IN. 25 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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