PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

A-254Restrictor Unit,fluid Flow

Dwyer Instruments Inc · NSN 4730-01-659-7893 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-01-659-7893 — this item is cataloged by the U.S. Government under National Stock Number 4730-01-659-7893. Primary manufacturer part number: A-254.
Features
  • Restrictor Unit,fluid Flow — FSC 4730
  • Mounting Hole Diameter: 0.25 INCHES NOMINAL IN
  • Width Across Flats: 25.0 MILLIMETERS NOMINAL MM
  • Mounting Hole Quantity: 1
  • Design Type: STRAIGHT
  • Operating Temp Range: -4.0 TO 302.0 FAHRENHEIT DEGF
  • Port Quantity: 1
  • Material: COPPER ALLOY OVERALL
Applications
  • Applications requiring Copper Alloy Overall construction
General Description

The Restrictor Unit,fluid Flow, cataloged under National Stock Number 4730-01-659-7893, 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 Dwyer Instruments Inc. Government technical data includes 12 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. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-01-659-7893
Primary Part NumberA-254
Item NameRestrictor Unit,fluid Flow
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerDwyer Instruments Inc
StatusACTIVE
Mounting Hole Diameter0.25 INCHES NOMINAL IN
Width Across Flats25.0 MILLIMETERS NOMINAL MM
Mounting Hole Quantity1
Design TypeSTRAIGHT
Operating Temp Range-4.0 TO 302.0 FAHRENHEIT DEGF
Port Quantity1
MaterialCOPPER ALLOY OVERALL
Thread SeriesNPT ALL CONNECTIONS
End Connection TypeTHREADED FEMALE SECOND CONNECTION
End Connection SimilarityNOT IDENTICAL
End Connection TypeTHREADED MALE FIRST CONNECTION
Pressure Rating5690.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
5915-00-208-4457241-0619-041 INTERCHANGEABLE
Filter,band Pass
Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems
1620-00-485-7640 INTERCHANGEABLE
Collar-Landing Gear
Cross-Reference Index
Part NumberManufacturer
A-254 PRIMARY Dwyer Instruments Inc (USA)
Related Parts
5915-00-208-4457INTERCHANGEABLE
FILTER,BAND PASS
241-0619-041
1620-00-485-7640INTERCHANGEABLE
COLLAR-LANDING GEAR

Frequently Asked Questions

What is NSN 4730-01-659-7893?

NSN 4730-01-659-7893 is a Restrictor Unit,fluid Flow, manufactured by Dwyer Instruments Inc, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-01-659-7893?

NSN 4730-01-659-7893 has 1 cross-referenced part number: A-254 (Dwyer Instruments Inc).

What NSN replaces 4730-01-659-7893?

There are 2 known substitutes for 4730-01-659-7893: 5915-00-208-4457, 1620-00-485-7640. Verify interchangeability with system specifications before substitution.

What are the specifications of A-254?

Key specifications for A-254: Mounting Hole Diameter: 0.25 INCHES NOMINAL IN; Overall Length: 55.0 MILLIMETERS NOMINAL MM; End Item Identification: 3655015452483; Width Across Flats: 25.0 MILLIMETERS NOMINAL MM. 16 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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