PartsTable
Technical Data Sheet
PartsTable / COMPONENT / 1551AS291-1
1551AS291-1 ✓ Verified by PartsTable
— · HOSE FITTING
WHAT YOU NEED TO KNOW
PTFE tape on tapered threads (NPT/BSPT) JIC/AN flare connections seal metal-to-metal — no tape
NPT != BSPT — look identical, NOT interchangeable
PRODUCT OVERVIEW

The TEE,TUBE is a the manufacturer industrial component. Key specifications include material: STEEL COMP 316 OVERALL, leg_length: 1.031 INCHES NOMINAL ALL ENDS IN, seat_angle: 20.0 DEGREES ALL ENDS, thread_class: 3A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE ALL ENDS, connection_style: FLARELESS (TUBE) ALL ENDS. This product is currently in active production with full OEM support.

This part is cataloged in the Federal Logistics Information System (FLIS) under NSN 4730-01-302-6642, 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
1551AS291-1
NSN: 4730-01-302-6642
FSC: 4730
CAGE: 30003 — NAVAL AIR SYSTEMS COMMAND MANAGED ORIGINAL DESIGN ACTIVITY NOT MATERIAL/PARTS SUPPLIER (USA)
SPECIFICATIONS
materialSTEEL COMP 316 OVERALL
leg_length1.031 INCHES NOMINAL ALL ENDS IN
seat_angle20.0 DEGREES ALL ENDS
thread_class3A ALL ENDS A
connection_typeTHREADED EXTERNAL TUBE ALL ENDS
connection_styleFLARELESS (TUBE) ALL ENDS
special_featuresUSED ON 3655-01-281-7747
nominal_thread_size0.438 INCHES ALL ENDS IN
fsc_application_dataEONS PSA UNIT
media_for_which_designedOXYGEN, LIQUID SINGLE RESPONSE
thread_series_designatorUNF ALL ENDS
furnished_items_and_quantity3 SHORT COUPLING NUT WITH SLEEVE
NSN4730-01-302-6642
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: 1551AS291-1 · 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
•
THREAD CLASS: 3A ALL ENDS A
•
CONNECTION STYLE: FLARELESS (TUBE) ALL ENDS
•
FURNISHED ITEMS AND QUANTITY: 3 SHORT COUPLING NUT WITH SLEEVE
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
•
MATERIAL: STEEL COMP 316 OVERALL
•
MEDIA FOR WHICH DESIGNED: OXYGEN, LIQUID SINGLE RESPONSE
•
NOMINAL THREAD SIZE: 0.438 INCHES ALL ENDS IN
TECHNICAL CHARACTERISTICS (FLIS)
THREAD CLASS3A ALL ENDS A
CONNECTION STYLEFLARELESS (TUBE) ALL ENDS
FURNISHED ITEMS AND QUANTITY3 SHORT COUPLING NUT WITH SLEEVE
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
MATERIALSTEEL COMP 316 OVERALL
SPECIAL FEATURESUSED ON 3655-01-281-7747
MEDIA FOR WHICH DESIGNEDOXYGEN, LIQUID SINGLE RESPONSE
NOMINAL THREAD SIZE0.438 INCHES ALL ENDS IN
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED0.250 INCHES ALL ENDS IN
CONNECTION TYPETHREADED EXTERNAL TUBE ALL ENDS
VERIFIED SUBSTITUTES & CROSS-REFERENCES 8
SS-400-3Interchangeable
interchangeable cross-reference
interchangeable
4730PL1816363Interchangeable
interchangeable cross-reference
interchangeable
4TTT-316Interchangeable
interchangeable cross-reference
interchangeable
400-3-316Interchangeable
interchangeable cross-reference
interchangeable
10338215Interchangeable
interchangeable cross-reference
interchangeable
1551AS291-1CPInterchangeable
interchangeable cross-reference
interchangeable
LIFECYCLE
StatusACTIVE
AvailabilityOEM and secondary market
RoHS CompliantEAR99Not HAZMAT
Ready to buy 1551AS291-1?
Compare prices from verified sellers on eBay
Buy on eBay →
As an eBay Partner, PartsTable may earn a commission. Your price is not affected.
FREQUENTLY ASKED QUESTIONS
What is 1551AS291-1?
1551AS291-1 is a TEE,TUBE.
What parts can replace 1551AS291-1?
There are 8 known substitutes for 1551AS291-1: SS-400-3, 4730PL1816363, 4TTT-316 and 5 more. Substitute compatibility should be verified for your specific system.
What is the NSN for 1551AS291-1?
1551AS291-1 is cataloged in the Federal Logistics Information System (FLIS) under NSN 4730-01-302-6642. This indicates validated use in U.S. government and defense supply chains.
Community Feedback
Comments (0)
No comments yet. Be the first to share what you know.
Leave a Comment
Comments are reviewed before appearing. You will receive an email to verify before your comment appears.

Request a Quote — 1551AS291-1

✓ Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com
Last verified: July 2026