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MK1540 — VALVE,SAFETY RELIEF

✓ Government record, cited
— · GATE VALVE
PRODUCT OVERVIEW

MK1540: VALVE,SAFETY RELIEF.

The VALVE,SAFETY RELIEF is a the manufacturer industrial component. Key specifications include special_features: 1-11 1/2 NPT THREAD 1.125 IN. LG IN, style_designator: STRAIGHT THRU, operating_pressure: 385.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS, valve_operation_method: AUTOMATIC.

This part is cataloged in the U.S. Government catalog under NSN 4820-00-887-1786, 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
MK1540
NSN: 4820-00-887-1786
FSC: 4820 — Valves, Nonpowered
CAGE: 11247 — LODESTONE CORP DIV OF FEDDERS CORP (USA)
SPECIFICATIONS
special_features1-11 1/2 NPT THREAD 1.125 IN. LG IN
style_designatorSTRAIGHT THRU
operating_pressure385.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
valve_operation_methodAUTOMATIC
NSN4820-00-887-1786
COMPONENT DIAGRAM
GATE VALVE — FULL OPEN OR FULL CLOSE ONLY Rising STEM BONNET FLOW → → FLOW SEATS — — SIZE: — · — · — PN: MK1540 · 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
•
STYLE DESIGNATOR: STRAIGHT THRU
•
OPERATING PRESSURE: 385.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
•
VALVE OPERATION METHOD: AUTOMATIC
TECHNICAL CHARACTERISTICS
STYLE DESIGNATORSTRAIGHT THRU
OPERATING PRESSURE385.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
SPECIAL FEATURES1-11 1/2 NPT THREAD 1.125 IN. LG IN
VALVE OPERATION METHODAUTOMATIC
SUBSTITUTES & CROSS-REFERENCES 5
B566-385Reference document
Same NSN cross-reference
Reference document — Secondary reference
PW1955ITEM34SH1Reference document
Same NSN cross-reference
Reference document — Secondary reference
B566S-385Reference document
Same NSN cross-reference
Reference document — Design control — primary reference
550541Reference document
Same NSN cross-reference
Reference document — Secondary reference
B566Reference document
Same NSN cross-reference
Reference document — Secondary reference
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 MK1540?
MK1540 is a VALVE,SAFETY RELIEF.
What parts can replace MK1540?
There are 5 known substitutes for MK1540: B566-385, PW1955ITEM34SH1, B566S-385 and 2 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MK1540?
MK1540 is cataloged in the U.S. Government catalog under NSN 4820-00-887-1786. 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.