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503-4C — SEAT,VALVE

✓ Government record, cited
— · GATE VALVE
PRODUCT OVERVIEW

503-4C: SEAT,VALVE.

The SEAT,VALVE is a the manufacturer industrial component. Key specifications include material: PLASTIC POLYAMIDE NYLON OVERALL, overall_height: 0.168 INCHES NOMINAL IN, style_designator: PLAIN, body_inside_diameter: 0.068 INCHES NOMINAL IN, body_outside_diameter: 0.405 INCHES NOMINAL IN, seating_surface_shape: FLAT. This part is cataloged in the U.S.

Government catalog under NSN 4820-00-234-3929, 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
503-4C
NSN: 4820-00-234-3929
NIINs: 002343929, 005860580
FSC: 4820 — Valves, Nonpowered
CAGE: 28968 — CIRCOR INSTRUMENTATION TECHNOLOGIES, INC. DBA HOKE GYROLOK (USA)
SPECIFICATIONS
materialPLASTIC POLYAMIDE NYLON OVERALL
overall_height0.168 INCHES NOMINAL IN
style_designatorPLAIN
body_inside_diameter0.068 INCHES NOMINAL IN
body_outside_diameter0.405 INCHES NOMINAL IN
seating_surface_shapeFLAT
material_document_and_classificationMIL-M-20693 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL
NSN4820-00-234-3929
COMPONENT DIAGRAM
GATE VALVE — FULL OPEN OR FULL CLOSE ONLY Rising STEM BONNET FLOW → → FLOW SEATS — — SIZE: — · — · — PN: 503-4C · OEM ⚠ VERIFY BEFORE ORDERING Gate valves = FULL OPEN or FULL CLOSE only — never throttle. Partial opening causes seat erosion and vibration. ✓ BROKER TIP Rising stem shows valve position visually — easier maintenance. Non-rising stem saves headroom. PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
CRITICALITY CODE JUSTIFICATION: ZZZY
•
REFERENCE NUMBER DIFFERENTIATING CHARACTERISTICS: MATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.
TECHNICAL CHARACTERISTICS
CRITICALITY CODE JUSTIFICATIONZZZY
REFERENCE NUMBER DIFFERENTIATING CHARACTERISTICSMATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.
SUBSTITUTES & CROSS-REFERENCES 8
01010-5 PC 8Reference document
Same NSN cross-reference
Reference document — Secondary reference
H503-4CReference document
Same NSN cross-reference
Reference document — Secondary reference
5314X1IM11Reference document
Same NSN cross-reference
Reference document — Secondary reference
H5314X1 PIECE 11Reference document
Same NSN cross-reference
Reference document — Secondary reference
5314XPC11Reference document
Same NSN cross-reference
Reference document — Secondary reference
5314M4PC11Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Demilitarization required (F)
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FREQUENTLY ASKED QUESTIONS
What is 503-4C?
503-4C is a SEAT,VALVE.
What parts can replace 503-4C?
There are 8 known substitutes for 503-4C: 01010-5 PC 8, H503-4C, 5314X1IM11 and 5 more. Substitute compatibility should be verified for your specific system.
What is the NSN for 503-4C?
503-4C is cataloged in the U.S. Government catalog under NSN 4820-00-234-3929. 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.