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ST521EA — BONNET,JACK,CAP

✓ Government record, cited
— · GATE VALVE
PRODUCT OVERVIEW

ST521EA: BONNET,JACK,CAP.

The BONNET,JACK,CAP is a the manufacturer industrial component. Key specifications include end_item_identification: HAYWARD INDUSTRIAL PRODUCTS INC DUPLEX STRAINER MODEL NO. 50,SIZE 6.000 IN.

IN, general_characteristics_item_description: DUCTILE IRON,250 PSI. This part is cataloged in the U.S. Government catalog under NSN 4820-01-278-4075, 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
ST521EA
NSN: 4820-01-278-4075
FSC: 4820 — Valves, Nonpowered
CAGE: 73124 — HAYWARDINDL. PRODUCTS, INC. (USA)
SPECIFICATIONS
end_item_identificationHAYWARD INDUSTRIAL PRODUCTS INC DUPLEX STRAINER MODEL NO. 50,SIZE 6.000 IN. IN
general_characteristics_item_descriptionDUCTILE IRON,250 PSI
NSN4820-01-278-4075
COMPONENT DIAGRAM
GATE VALVE — FULL OPEN OR FULL CLOSE ONLY Rising STEM BONNET FLOW → → FLOW SEATS — — SIZE: — · — · — PN: ST521EA · 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
•
GENERAL CHARACTERISTICS ITEM DESCRIPTION: DUCTILE IRON,250 PSI
TECHNICAL CHARACTERISTICS
GENERAL CHARACTERISTICS ITEM DESCRIPTIONDUCTILE IRON,250 PSI
END ITEM IDENTIFICATIONHAYWARD INDUSTRIAL PRODUCTS INC DUPLEX STRAINER MODEL NO. 50,SIZE 6.000 IN. IN
OTHER ITEMS IN FSC 4820 — Valves, Nonpowered
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
4820-00-000-0097 4820-00-001-0010 4820-00-001-0020 4820-00-001-0021 4820-00-001-0032 4820-00-001-0037 4820-00-001-0042 4820-00-001-1230
SUBSTITUTES & CROSS-REFERENCES

No substitute or cross-reference records for this part.

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 ST521EA?
ST521EA is a BONNET,JACK,CAP.
What is the NSN for ST521EA?
ST521EA is cataloged in the U.S. Government catalog under NSN 4820-01-278-4075. 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.