Bonnet, Jack, Cap4820-01-278-4075

NSN 4820-01-278-4075 · NIIN 012784075 · Part number ST521EA

Haywardindl. Products, Inc. · FSC 4820 — Valves, Nonpowered · FSG 48 — Valves · CAGE 73124

Government record, cited

NSN 4820-01-278-4075 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-278-4075. Manufacturer of record part number: ST521EA.

Also searched as 4820-01-278-4075 · 4820012784075 · NIIN 012784075 · 01-278-4075 · FSC 4820 Valves, Nonpowered · CAGE 73124 · ST521EA

Nearby stock numbers ← 4820-01-278-4074 Manifold Assembly, Pressure Reduc · 4820-01-278-4081 →

4820-01-278-4075 — Valves, Nonpowered

Features

Bonnet,jack,cap — FSC 4820
General Characteristics Item Description: DUCTILE IRON,250 PSI
1 manufacturer part number on file
Manufacturer of record: Haywardindl. Products, Inc.

Identification

NSN: 4820-01-278-4075
NIIN: 012784075
FSC: 4820 — Valves, Nonpowered
FSG: 48 — Valves
Primary part number: ST521EA
Manufacturer: Haywardindl. Products, Inc.

General Description

The Bonnet,jack,cap, cataloged under National Stock Number 4820-01-278-4075, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Haywardindl. Products, Inc.. Government technical data includes 1 specification, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.

Technical Specifications

Parameter	Value
NSN	4820-01-278-4075
Primary Part Number	ST521EA
Item Name	Bonnet,jack,cap
FSC / FSG	4820 / 48 — Valves, Nonpowered
Manufacturer	Haywardindl. Products, Inc.
Status	ACTIVE
General Characteristics Item Description	DUCTILE IRON,250 PSI

Lifecycle & Compliance

Acquisition Status	ACTIVE
DEMIL Code	DEMIL A — No Demilitarization Required
Hazard	No hazard code in the DLA record (HMIC N)
Criticality Code	X

Cross-Reference Index

Part Number	Manufacturer
ST521EA PRIMARY	Haywardindl. Products, Inc. (USA)

No interchangeability data on file.

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

4820-00-000-0097 · Item name not on file

4820-00-001-0010

VALVE,ROTARY,SELECTOR

4820-00-001-0020

4820-00-001-0020 · Item name not on file

4820-00-001-0021

4820-00-001-0021 · Item name not on file

4820-00-001-0032

4820-00-001-0032 · Item name not on file

4820-00-001-0037

VALVE,SAFETY RELIEF

4820-00-001-0042

4820-00-001-0042 · Item name not on file

4820-00-001-1230

4820-00-001-1230 · Item name not on file

Frequently Asked Questions

What is NSN 4820-01-278-4075?

NSN 4820-01-278-4075 is a Bonnet,jack,cap, manufactured by Haywardindl. Products, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.

What part numbers are listed for NSN 4820-01-278-4075?

NSN 4820-01-278-4075 has 1 manufacturer part number on file: ST521EA (Haywardindl. Products, Inc.).

What are the specifications of ST521EA?

Key specifications for ST521EA: General Characteristics Item Description: DUCTILE IRON,250 PSI; End Item Identification: HAYWARD INDUSTRIAL PRODUCTS INC DUPLEX STRAINER MODEL NO. 50,SIZE 6.000 IN. IN. 1 specification is documented in the U.S. Government catalog.

Is NSN 4820-01-278-4075 hazardous material?

No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.

Sources

U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.

U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.

✓ Data cited from the U.S. Government catalog; commercial cross-references from OEM and certified industry sources.

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