PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

20821Valve,check

Allied Systems Company Dba Allied Systems Co · NSN 4820-01-355-6289 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-355-6289 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-355-6289. Primary manufacturer part number: 20821.
Features
  • Valve,check — FSC 4820
  • Media for Which Designed: OIL, HYDRAULIC SINGLE RESPONSE
  • Valve Operation Method: AUTOMATIC
  • 1 verified cross-reference
  • Primary manufacturer: Allied Systems Company Dba Allied Systems Co
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
General Description

The Valve,check, cataloged under National Stock Number 4820-01-355-6289, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Allied Systems Company Dba Allied Systems Co. Government technical data includes 2 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-355-6289
Primary Part Number20821
Item NameValve,check
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerAllied Systems Company Dba Allied Systems Co
StatusACTIVE
Media for Which DesignedOIL, HYDRAULIC SINGLE RESPONSE
Valve Operation MethodAUTOMATIC
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
5133-00-065-098102-R18C-21 INTERCHANGEABLE
Drill,twist
Us Air Tool Co Inc Dba Us Air Tool Co Inc
5365-00-401-9318 INTERCHANGEABLE
Bushing,pump
5935-00-854-6840RP14391G1 INTERCHANGEABLE
Socket,plug-in Electronic Compon
Te Connectivity Corporation
6120-00-965-8357900406-11 INTERCHANGEABLE
Power Supply
Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp
5180-01-121-0078208-21 INTERCHANGEABLE
Tool Kit,wheel Alignment
Hunter Engineering Company Inc
1680-01-201-16892082-1 INTERCHANGEABLE
Cylinder Assembly,reaction
Real-Time Laboratories, Llc
7930-01-508-371220821 INTERCHANGEABLE
Cleaner,industrial,multi Purpose
State Industrial Products Corp Dba State Industrial Products Div State Chemical Solutions
Cross-Reference Index
Part NumberManufacturer
20821 PRIMARY Allied Systems Company Dba Allied Systems Co (USA)
Related Parts
5133-00-065-0981INTERCHANGEABLE
DRILL,TWIST
02-R18C-21
5365-00-401-9318INTERCHANGEABLE
BUSHING,PUMP
5935-00-854-6840INTERCHANGEABLE
SOCKET,PLUG-IN ELECTRONIC COMPON
RP14391G1
6120-00-965-8357INTERCHANGEABLE
POWER SUPPLY
900406-11
5180-01-121-0078INTERCHANGEABLE
TOOL KIT,WHEEL ALIGNMENT
208-21
1680-01-201-1689INTERCHANGEABLE
CYLINDER ASSEMBLY,REACTION
2082-1
7930-01-508-3712INTERCHANGEABLE
CLEANER,INDUSTRIAL,MULTI PURPOSE
20821

Frequently Asked Questions

What is NSN 4820-01-355-6289?

NSN 4820-01-355-6289 is a Valve,check, manufactured by Allied Systems Company Dba Allied Systems Co, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-355-6289?

NSN 4820-01-355-6289 has 1 cross-referenced part number: 20821 (Allied Systems Company Dba Allied Systems Co).

What NSN replaces 4820-01-355-6289?

There are 7 known substitutes for 4820-01-355-6289: 5133-00-065-0981, 5365-00-401-9318, 5935-00-854-6840 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 20821?

Key specifications for 20821: Media for Which Designed: OIL, HYDRAULIC SINGLE RESPONSE; Special Features: USED ON A CRANE; Valve Operation Method: AUTOMATIC. 3 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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