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21138 ITEM 56 — RESTRICTOR,FLUID FLOW

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

21138 ITEM 56: RESTRICTOR,FLUID FLOW.

The RESTRICTOR,FLUID FLOW is a the manufacturer industrial component. Key specifications include material: STEEL CORROSION RESISTING, end_item_identification: SEAWOLF CLASS SSN, VALVE,DIRECTIONAL.. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-417-6722, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
21138 ITEM 56
NSN: 4730-01-417-6722
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 78062 — SARGENT AEROSPACE & DEFENSE, LLC DBA SARGENT CONTROLS & AEROSPACE DIV SARGENT CONTROLS & AEROSPACE (USA)
SPECIFICATIONS
materialSTEEL CORROSION RESISTING
end_item_identificationSEAWOLF CLASS SSN, VALVE,DIRECTIONAL.
NSN4730-01-417-6722
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: 21138 ITEM 56 · OEM ⚠ VERIFY BEFORE ORDERING NPT ≠ BSPT — tapered threads look identical but are NOT interchangeable. Wrong thread = leak. JIC (37°) ≠ AN (37°) ≠ SAE 45° — flare angles must match exactly. Measure thread pitch with gauge — visual identification is unreliable ✓ BROKER TIP Always use thread sealant (PTFE tape or pipe compound) on tapered threads (NPT/BSPT). JIC/AN flare fittings seal metal-to-metal — never use tape on flare connections PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
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MATERIAL: STEEL CORROSION RESISTING
TECHNICAL CHARACTERISTICS
END ITEM IDENTIFICATIONSEAWOLF CLASS SSN, VALVE,DIRECTIONAL.
MATERIALSTEEL CORROSION RESISTING
SUBSTITUTES & CROSS-REFERENCES 1
21138Reference document
Same NSN cross-reference
Reference document — Drawing number reference only
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 21138 ITEM 56?
21138 ITEM 56 is a RESTRICTOR,FLUID FLOW.
What parts can replace 21138 ITEM 56?
There is 1 known substitute for 21138 ITEM 56: 21138. Substitute compatibility should be verified for your specific system.
What is the NSN for 21138 ITEM 56?
21138 ITEM 56 is cataloged in the U.S. Government catalog under NSN 4730-01-417-6722. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.