PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

5221Valve,safety Relief

Henry Technologies, Inc. · NSN 4820-00-585-8566 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-585-8566 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-585-8566. Primary manufacturer part number: 5221.
Features
  • Valve,safety Relief — FSC 4820
  • Nominal Pipe Size Accommodated: 0.250 INCHES FIRST END IN
  • Connection Type: THREADED EXTERNAL PIPE FIRST END
  • Material: COPPER ALLOY STEM
  • Material: STEEL SEAT
  • Maximum Operating Temp: 200.0 FAHRENHEIT SINGLE RESPONSE DEGF
  • Valve Operation Method: AUTOMATIC
  • Opening Pressure Setting: 325.0 POUNDS PER SQUARE INCH LBS
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Stem construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-585-8566, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Henry Technologies, Inc.. Government technical data includes 23 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-585-8566
Primary Part Number5221
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerHenry Technologies, Inc.
StatusACTIVE
Nominal Pipe Size Accommodated0.250 INCHES FIRST END IN
Connection TypeTHREADED EXTERNAL PIPE FIRST END
MaterialCOPPER ALLOY STEM
MaterialSTEEL SEAT
Maximum Operating Temp200.0 FAHRENHEIT SINGLE RESPONSE DEGF
Valve Operation MethodAUTOMATIC
Opening Pressure Setting325.0 POUNDS PER SQUARE INCH LBS
Disk Loading MethodSPRING
Flow Control DeviceDISK
Bonnet TypeINSIDE SPRING
Features ProvidedVALVE STEM LOCK SHIELD
Nominal Thread Size0.250 INCHES FIRST END IN
MaterialCOPPER ALLOY BODY
Operating Pressure350.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Media for Which DesignedSTEAM SINGLE RESPONSE
Style DesignatorANGLE
Thread Series DesignatorNPT FIRST END
Thread DirectionRIGHT-HAND FIRST END
Bonnet Attachment MethodINTEGRAL
MaterialCOPPER ALLOY AND RUBBER SYNTHETIC FLOW CONTROL DEVICE
Connection StylePLAIN (PIPE) FIRST END
Valve Discharge Flow Rate504.0 POUNDS PER HOUR LBS
Thread Quantity Per Inch18 FIRST END
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
3110-00-100-04962X627B INTERCHANGEABLE
Cup,tapered Roller Bearing
Napco International Llc Dba Napco International Inc
5975-00-100-8716 INTERCHANGEABLE
Box Connector,electrical
5330-00-171-90104006145-3 INTERCHANGEABLE
Gasket
Agco Corp Parts Opn
6105-00-213-7427 INTERCHANGEABLE
Motor,alternating Current
4510-00-215-8019 INTERCHANGEABLE
Handle,faucet
5975-00-317-311696T075 INTERCHANGEABLE
Box Connector,electrical
Egs Electrical Group Appleton Div
5950-00-433-719210182075 INTERCHANGEABLE
Transformer,power
Us Army Aviation and Missile Command
5910-00-528-9190914004-1B INTERCHANGEABLE
Capacitor,variable,air Dielectri
Raytheon Company Dba Raytheon
5950-00-645-37065221 INTERCHANGEABLE
Coil,radio Frequency
Bourns Inc
5330-00-765-2912G9-151139 INTERCHANGEABLE
Gasket
Norwalk Compreseer Company Inc Dba Norwalk Compressor Company
Cross-Reference Index
Part NumberManufacturer
5221 Henry Technologies, Inc. (USA)
5221-325 Henry Technologies, Inc. (USA)
Related Parts
3110-00-100-0496INTERCHANGEABLE
CUP,TAPERED ROLLER BEARING
2X627B
5975-00-100-8716INTERCHANGEABLE
BOX CONNECTOR,ELECTRICAL
5330-00-171-9010INTERCHANGEABLE
GASKET
4006145-3
6105-00-213-7427INTERCHANGEABLE
MOTOR,ALTERNATING CURRENT
4510-00-215-8019INTERCHANGEABLE
HANDLE,FAUCET
5975-00-317-3116INTERCHANGEABLE
BOX CONNECTOR,ELECTRICAL
96T075
5950-00-433-7192INTERCHANGEABLE
TRANSFORMER,POWER
10182075
5910-00-528-9190INTERCHANGEABLE
CAPACITOR,VARIABLE,AIR DIELECTRI
914004-1B
5950-00-645-3706INTERCHANGEABLE
COIL,RADIO FREQUENCY
5221
5330-00-765-2912INTERCHANGEABLE
GASKET
G9-151139
4820-00-845-4168INTERCHANGEABLE
VALVE,SAFETY RELIEF
9975258
2590-00-888-9398INTERCHANGEABLE
CABLE ASSEMBLY,HAND
522-1

Frequently Asked Questions

What is NSN 4820-00-585-8566?

NSN 4820-00-585-8566 is a Valve,safety Relief, manufactured by Henry Technologies, Inc., classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-585-8566?

NSN 4820-00-585-8566 has 2 cross-referenced part numbers: 5221 (Henry Technologies, Inc.), 5221-325 (Henry Technologies, Inc.).

What NSN replaces 4820-00-585-8566?

There are 12 known substitutes for 4820-00-585-8566: 3110-00-100-0496, 5975-00-100-8716, 5330-00-171-9010 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 5221?

Key specifications for 5221: Nominal Pipe Size Accommodated: 0.250 INCHES FIRST END IN; Connection Type: THREADED EXTERNAL PIPE FIRST END; Material: COPPER ALLOY STEM; Material: STEEL SEAT. 23 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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