PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

1768Valve,safety Relief

Lunkenheimer Co · NSN 4820-00-542-5821 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-542-5821 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-542-5821. Primary manufacturer part number: 1768.
Features
  • Valve,safety Relief — FSC 4820
  • Connection Type: THREADED EXTERNAL PIPE FIRST END
  • Disk Loading Method: SPRING
  • Operating Pressure: 2200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Material: COPPER ALLOY BODY
  • Nominal Thread Size: 0.500 INCHES FIRST END IN
  • Reference Number Differentiating Characteristics: AS DIFFERENTIATED BY REPLY TO PAC ADSW
  • Style Designator: STRAIGHT THRU
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Body construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-542-5821, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Lunkenheimer Co. Government technical data includes 20 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. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-542-5821
Primary Part Number1768
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerLunkenheimer Co
StatusACTIVE
Connection TypeTHREADED EXTERNAL PIPE FIRST END
Disk Loading MethodSPRING
Operating Pressure2200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
MaterialCOPPER ALLOY BODY
Nominal Thread Size0.500 INCHES FIRST END IN
Reference Number Differentiating CharacteristicsAS DIFFERENTIATED BY REPLY TO PAC ADSW
Style DesignatorSTRAIGHT THRU
Thread Series DesignatorNPT FIRST END
Media for Which DesignedAIR SINGLE RESPONSE
Bonnet TypeINSIDE SPRING
Thread DirectionRIGHT-HAND FIRST END
MaterialCOPPER ALLOY FLOW CONTROL DEVICE
Bonnet Attachment MethodTHREADED
Nominal Pipe Size Accommodated0.500 INCHES FIRST END IN
Connection StylePLAIN (PIPE) FIRST END
Flow Control DeviceDISK
Adjustable Pressure Range+1401.0 TO 2200.0 POUNDS PER SQUARE INCH LBS
Valve Operation MethodAUTOMATIC OR MANUAL
MaterialCOPPER ALLOY SEAT
MaterialCOPPER ALLOY STEM
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
6685-00-061-4146 INTERCHANGEABLE
Thermometer,self-Indicating,bime
3110-00-155-9618056-4 INTERCHANGEABLE
Bearing,ball,annular
Lockheed Martin Corporation Div Rms - Mitchel Field
6240-00-269-096415A1395-2 INTERCHANGEABLE
Lamp,incandescent
Northrop Grumman Systems Corporation
4730-00-336-92661768 INTERCHANGEABLE
Strainer Element,sediment
Wayne Wire Cloth Products, Inc
5360-00-374-526553027 INTERCHANGEABLE
Spring,helical,torsion
R. H. Sheppard Co., Inc. Dba Sheppard
2940-00-405-7377117-4418 INTERCHANGEABLE
Filter Element,fluid
Wartsila Canada Inc
4820-00-446-3497118822PC15 INTERCHANGEABLE
Valve,safety Relief
Curtiss-Wright Electro-Mechanical Corp Dba Steam & Air Solutions Div Curtiss-Wright Steam and Air Solutions
4820-00-446-3560114972PC11 INTERCHANGEABLE
Valve,safety Relief
Curtiss-Wright Electro-Mechanical Corporation Div Epd
5905-00-518-82811 3-4D48F303J INTERCHANGEABLE
Resistor,fixed,wire Wound,induct
Ohmite Holding, L.l.c. Dba Ohmite Manufacturing
5950-00-995-0092E11142 INTERCHANGEABLE
Reactor
Electro Engineering Works Inc
Cross-Reference Index
Part NumberManufacturer
1768 Lunkenheimer Co (USA)
Related Parts
6685-00-061-4146INTERCHANGEABLE
THERMOMETER,SELF-INDICATING,BIME
3110-00-155-9618INTERCHANGEABLE
BEARING,BALL,ANNULAR
056-4
6240-00-269-0964INTERCHANGEABLE
LAMP,INCANDESCENT
15A1395-2
4730-00-336-9266INTERCHANGEABLE
STRAINER ELEMENT,SEDIMENT
1768
5360-00-374-5265INTERCHANGEABLE
SPRING,HELICAL,TORSION
53027
2940-00-405-7377INTERCHANGEABLE
FILTER ELEMENT,FLUID
117-4418
4820-00-446-3497INTERCHANGEABLE
VALVE,SAFETY RELIEF
118822PC15
4820-00-446-3560INTERCHANGEABLE
VALVE,SAFETY RELIEF
114972PC11
5905-00-518-8281INTERCHANGEABLE
RESISTOR,FIXED,WIRE WOUND,INDUCT
1 3-4D48F303J
5950-00-995-0092INTERCHANGEABLE
REACTOR
E11142
9330-01-011-2431INTERCHANGEABLE
PLASTIC SHEET
4820-01-062-7075INTERCHANGEABLE
CARTRIDGE,VALVE
09-20314-10

Frequently Asked Questions

What is NSN 4820-00-542-5821?

NSN 4820-00-542-5821 is a Valve,safety Relief, manufactured by Lunkenheimer Co, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-542-5821?

NSN 4820-00-542-5821 has 1 cross-referenced part number: 1768 (Lunkenheimer Co).

What NSN replaces 4820-00-542-5821?

There are 12 known substitutes for 4820-00-542-5821: 6685-00-061-4146, 3110-00-155-9618, 6240-00-269-0964 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 1768?

Key specifications for 1768: Connection Type: THREADED EXTERNAL PIPE FIRST END; Disk Loading Method: SPRING; Operating Pressure: 2200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS; Material: COPPER ALLOY BODY. 21 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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