PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

66251Reducer,pipe

Mine Safety Appliances Company · NSN 4730-01-379-2133 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-01-379-2133 — this item is cataloged by the U.S. Government under National Stock Number 4730-01-379-2133. Primary manufacturer part number: 66251.
Features
  • Reducer,pipe — FSC 4730
  • Connection Type: THREADED INTERNAL PIPE SECOND END
  • Nominal Thread Size: 0.250 INCHES SECOND END IN
  • Maximum Operating Temp: 40.0 FAHRENHEIT SINGLE RESPONSE DEGF
  • Operating Pressure: 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Nominal Thread Size: 0.500 INCHES FIRST END IN
  • Thread Series Designator: NPT FIRST END
  • Connection Type: THREADED INTERNAL PIPE FIRST END
Applications
  • Fluid conveyance
  • Hydraulic system plumbing
  • Pneumatic line routing
General Description

The Reducer,pipe, cataloged under National Stock Number 4730-01-379-2133, 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 Mine Safety Appliances Company. Government technical data includes 11 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 6 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-01-379-2133
Primary Part Number66251
Item NameReducer,pipe
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerMine Safety Appliances Company
StatusACTIVE
Connection TypeTHREADED INTERNAL PIPE SECOND END
Nominal Thread Size0.250 INCHES SECOND END IN
Maximum Operating Temp40.0 FAHRENHEIT SINGLE RESPONSE DEGF
Operating Pressure100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Nominal Thread Size0.500 INCHES FIRST END IN
Thread Series DesignatorNPT FIRST END
Connection TypeTHREADED INTERNAL PIPE FIRST END
Connection StylePLAIN (PIPE) SECOND END
Thread Series DesignatorNPT SECOND END
Connection StylePLAIN (PIPE) FIRST END
Reducer TypeCONCENTRIC
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 6
5330-00-310-908066251 INTERCHANGEABLE
Gasket
Curtiss-Wright Controls, Inc. Div Actuation Division
4730-00-595-0083 INTERCHANGEABLE
Coupling Half,quick Disconnect
3040-01-006-757414-73909-3 INTERCHANGEABLE
Connecting Link,rigid
Northrop Grumman Systems Corporation
6105-01-353-07726625-1 INTERCHANGEABLE
Stator,motor
Ge Aviation Systems Llc Dba Ge Aviation Systems Llc
5985-01-477-181066251 INTERCHANGEABLE
Attenuator Assembly
Viavi Solutionsllc
8125-01-497-2341101010 INTERCHANGEABLE
Bottle,screw Cap
Fluid Defense Systems, Llc Dba Fluid Defense Systems
Cross-Reference Index
Part NumberManufacturer
66251 Mine Safety Appliances Company, Llc Dba M S a (USA)
66251 PRIMARY Mine Safety Appliances Company (USA)
Related Parts
5330-00-310-9080INTERCHANGEABLE
GASKET
66251
4730-00-595-0083INTERCHANGEABLE
COUPLING HALF,QUICK DISCONNECT
3040-01-006-7574INTERCHANGEABLE
CONNECTING LINK,RIGID
14-73909-3
6105-01-353-0772INTERCHANGEABLE
STATOR,MOTOR
6625-1
5985-01-477-1810INTERCHANGEABLE
ATTENUATOR ASSEMBLY
66251
8125-01-497-2341INTERCHANGEABLE
BOTTLE,SCREW CAP
101010

Frequently Asked Questions

What is NSN 4730-01-379-2133?

NSN 4730-01-379-2133 is a Reducer,pipe, manufactured by Mine Safety Appliances Company, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-01-379-2133?

NSN 4730-01-379-2133 has 2 cross-referenced part numbers: 66251 (Mine Safety Appliances Company, Llc Dba M S a), 66251 (Mine Safety Appliances Company).

What NSN replaces 4730-01-379-2133?

There are 6 known substitutes for 4730-01-379-2133: 5330-00-310-9080, 4730-00-595-0083, 3040-01-006-7574 and 3 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 66251?

Key specifications for 66251: Connection Type: THREADED INTERNAL PIPE SECOND END; Nominal Thread Size: 0.250 INCHES SECOND END IN; Maximum Operating Temp: 40.0 FAHRENHEIT SINGLE RESPONSE DEGF; Operating Pressure: 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 12 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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