PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MILU18250Union,pipe

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 4730-00-189-2598 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-189-2598 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-189-2598. Primary manufacturer part number: MILU18250.
Features
  • Union,pipe — FSC 4730
  • Nondefinitive Spec/std Data: XA TYPE
  • Style Designator: SCREWED
  • Media for Which Designed: STEAM SINGLE RESPONSE
  • Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Style Designator: SCREWED
  • Nominal Thread Size: 0.750 INCHES ALL ENDS IN
  • Material Document and Classification: ASTM A197 ASSN STD 1ST MATERIAL RESPONSE OVERALL
Applications
  • Fluid conveyance
  • Hydraulic system plumbing
  • Pneumatic line routing
  • Applications requiring Iron Overall construction
General Description

The Union,pipe, cataloged under National Stock Number 4730-00-189-2598, 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 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 26 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4730-00-189-2598
Primary Part NumberMILU18250
Item NameUnion,pipe
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusCANCELLED
Nondefinitive Spec/std DataXA TYPE
Style DesignatorSCREWED
Media for Which DesignedSTEAM SINGLE RESPONSE
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Style DesignatorSCREWED
Nominal Thread Size0.750 INCHES ALL ENDS IN
Material Document and ClassificationASTM A197 ASSN STD 1ST MATERIAL RESPONSE OVERALL
Nominal Overall Length2.094 INCHES IN
Nominal Thread Size0.750 INCHES ALL ENDS IN
Reducer TypeCONCENTRIC
MaterialIRON OVERALL
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Media for Which DesignedSTEAM SINGLE RESPONSE
Maximum Operating Temp218.0 CELSIUS SINGLE RESPONSE DEGC
Seat TypeGROUND-JOINT
MaterialIRON OVERALL
Thread Series DesignatorNPT ALL ENDS
Nominal Overall Length2.094 INCHES IN
Coupling Flange ShapeHEXAGON
Material Document and ClassificationASTM A197 ASSN STD 1ST MATERIAL RESPONSE OVERALL
Seat TypeGROUND-JOINT
Connection StylePLAIN (PIPE) ALL ENDS
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Nondefinitive Spec/std DataXA TYPE
Thread Series DesignatorNPT ALL ENDS
Coupling Flange ShapeHEXAGON
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
4730-00-189-2599 INTERCHANGEABLE
Union,pipe
4730-00-189-2600 INTERCHANGEABLE
Union,pipe
4730-00-189-26021631-400 INTERCHANGEABLE
Union,pipe
Flaton Machine Works Inc.
4730-00-189-2605 INTERCHANGEABLE
Union,pipe
4730-00-189-2606 INTERCHANGEABLE
Union,pipe
4730-00-189-2629 INTERCHANGEABLE
Union,pipe
4730-00-189-2630 INTERCHANGEABLE
Union,pipe
4730-00-189-2635 INTERCHANGEABLE
Union,pipe
4730-00-189-2638 INTERCHANGEABLE
Union,pipe
4730-00-189-2639 INTERCHANGEABLE
Union,pipe
Cross-Reference Index
Part NumberManufacturer
MILU18250 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
519-3-4 Crane Co Div Valve Div (USA)
MILU18250 Allied Plumbing Sales Co Inc (USA)
B16.39 The American Society of Mechanical Engineers (USA)
Related Parts
4730-00-189-2599INTERCHANGEABLE
UNION,PIPE
4730-00-189-2600INTERCHANGEABLE
UNION,PIPE
4730-00-189-2602INTERCHANGEABLE
UNION,PIPE
1631-400
4730-00-189-2605INTERCHANGEABLE
UNION,PIPE
4730-00-189-2606INTERCHANGEABLE
UNION,PIPE
4730-00-189-2629INTERCHANGEABLE
UNION,PIPE
4730-00-189-2630INTERCHANGEABLE
UNION,PIPE
4730-00-189-2635INTERCHANGEABLE
UNION,PIPE
4730-00-189-2638INTERCHANGEABLE
UNION,PIPE
4730-00-189-2639INTERCHANGEABLE
UNION,PIPE
4730-00-189-2645INTERCHANGEABLE
UNION,PIPE
4730-00-189-2646INTERCHANGEABLE
UNION,PIPE

Frequently Asked Questions

What is NSN 4730-00-189-2598?

NSN 4730-00-189-2598 is a Union,pipe, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 4730 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4730-00-189-2598?

NSN 4730-00-189-2598 has 4 cross-referenced part numbers: MILU18250 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 519-3-4 (Crane Co Div Valve Div), MILU18250 (Allied Plumbing Sales Co Inc), B16.39 (The American Society of Mechanical Engineers).

What NSN replaces 4730-00-189-2598?

There are 12 known substitutes for 4730-00-189-2598: 4730-00-189-2599, 4730-00-189-2600, 4730-00-189-2602 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MILU18250?

Key specifications for MILU18250: Nondefinitive Spec/std Data: XA TYPE; Style Designator: SCREWED; Media for Which Designed: STEAM SINGLE RESPONSE; Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 26 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4730-00-189-2598 still in active supply?

NSN 4730-00-189-2598 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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