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056421 ITEM 18 — CYLINDER ASSEMBLY,ACTUATING,LINE

✓ Government record, cited
— · GATE VALVE
PRODUCT OVERVIEW

056421 ITEM 18: CYLINDER ASSEMBLY,ACTUATING,LINE.

CYLINDER ASSEMBLY,ACTUATING,LINE. Key specifications include material: STEEL SEAT, overall_height: 0.826 INCHES MINIMUM AND 0.828 INCHES MAXIMUM IN, style_designator: PLAIN, body_inside_diameter: 6.125 INCHES MINIMUM AND 6.126 INCHES MAXIMUM IN, body_outside_diameter: 6.562 INCHES NOMINAL IN, seating_surface_shape: FLAT. This part is cataloged in the U.S.

Government catalog under NSN 4820-01-161-6472, 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
056421 ITEM 18
NSN: 4820-01-161-6472
FSC: 4820 — Valves, Nonpowered
CAGE: 48422 — WILLIAM POWELL COMPANY, THE DBA POWELL VALVE DIV THE STARFLO CORPORATION (USA)
SPECIFICATIONS
materialSTEEL SEAT
overall_height0.826 INCHES MINIMUM AND 0.828 INCHES MAXIMUM IN
style_designatorPLAIN
body_inside_diameter6.125 INCHES MINIMUM AND 6.126 INCHES MAXIMUM IN
body_outside_diameter6.562 INCHES NOMINAL IN
seating_surface_shapeFLAT
end_item_identificationWM. POWELL CO. GATE VALVE MDL 1503N
NSN4820-01-161-6472
COMPONENT DIAGRAM
GATE VALVE — FULL OPEN OR FULL CLOSE ONLY Rising STEM BONNET FLOW → → FLOW SEATS — — SIZE: — · — · — PN: 056421 ITEM 18 · 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
•
BODY OUTSIDE DIAMETER: 6.562 INCHES NOMINAL IN
•
STYLE DESIGNATOR: PLAIN
•
BODY INSIDE DIAMETER: 6.125 INCHES MINIMUM AND 6.126 INCHES MAXIMUM IN
•
MATERIAL: STEEL SEAT
•
SEATING SURFACE SHAPE: FLAT
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.826 INCHES MINIMUM AND 0.828 INCHES MAXIMUM IN
BODY OUTSIDE DIAMETER6.562 INCHES NOMINAL IN
STYLE DESIGNATORPLAIN
BODY INSIDE DIAMETER6.125 INCHES MINIMUM AND 6.126 INCHES MAXIMUM IN
END ITEM IDENTIFICATIONWM. POWELL CO. GATE VALVE MDL 1503N
MATERIALSTEEL SEAT
SEATING SURFACE SHAPEFLAT
SUBSTITUTES & CROSS-REFERENCES 1
056421Reference 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 056421 ITEM 18?
056421 ITEM 18 is a CYLINDER ASSEMBLY,ACTUATING,LINE.
What parts can replace 056421 ITEM 18?
There is 1 known substitute for 056421 ITEM 18: 056421. Substitute compatibility should be verified for your specific system.
What is the NSN for 056421 ITEM 18?
056421 ITEM 18 is cataloged in the U.S. Government catalog under NSN 4820-01-161-6472. 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.