PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

1535-1SIZE1 1-2Valve,safety Relief

Richards R W Co · NSN 4820-00-814-1957 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-814-1957 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-814-1957. Primary manufacturer part number: 1535-1SIZE1 1-2.
Features
  • Valve,safety Relief — FSC 4820
  • Features Provided: PRESSURE TIGHT OUTLET SIDE
  • Connection Type: THREADED INTERNAL PIPE ALL ENDS
  • Thread Direction: RIGHT-HAND ALL ENDS
  • Maximum Operating Temp: 200.0 FAHRENHEIT SINGLE RESPONSE DEGF
  • Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS
  • Valve Operation Method: AUTOMATIC
  • Style Designator: ANGLE
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Overall construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-814-1957, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Richards R W Co. Government technical data includes 20 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-814-1957
Primary Part Number1535-1SIZE1 1-2
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerRichards R W Co
StatusACTIVE
Features ProvidedPRESSURE TIGHT OUTLET SIDE
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Thread DirectionRIGHT-HAND ALL ENDS
Maximum Operating Temp200.0 FAHRENHEIT SINGLE RESPONSE DEGF
Connection StylePLAIN,OPTIONAL END(PIPE) ALL ENDS
Valve Operation MethodAUTOMATIC
Style DesignatorANGLE
Media for Which DesignedWATER-OIL-GAS SINGLE RESPONSE
Thread Series DesignatorNPT ALL ENDS
Valve Discharge Flow Rate314.0 GALLONS PER MINUTE
Operating Pressure4000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Opening Pressure Setting750.0 POUNDS PER SQUARE INCH LBS
MaterialCOPPER ALLOY OVERALL
Nominal Pipe Size Accommodated1.500 INCHES ALL ENDS IN
Disk Loading MethodSPRING
Nominal Thread Size1.500 INCHES ALL ENDS IN
Thread Quantity Per Inch11-1/2 ALL ENDS
Bonnet TypeINSIDE SPRING
Bonnet Attachment MethodTHREADED
Flow Control DeviceDISK
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 9
4920-00-010-0596153-51 INTERCHANGEABLE
Pick-Up Modificatio
Te Connectivity Corporation
2920-00-350-439415351 INTERCHANGEABLE
Gear
Goodrich Corporation Dba Goodrich Corp
4810-00-706-800415351 INTERCHANGEABLE
Valve,solenoid
Eaton Aerospace Llc
4710-01-036-7552T-8-3-635 INTERCHANGEABLE
Tube Assembly,metal
Todd Combustion Inc
4710-01-037-132415351 INTERCHANGEABLE
Tube Assembly,metal
Todd Combustion Inc
4530-01-047-00051045466 INTERCHANGEABLE
Jet Tube,inlet,oil Burner
John Zink Company Llc
3020-01-155-589814095623 INTERCHANGEABLE
Sprocket Wheel
General Motors Llc Dba General Motors Llc
4320-01-194-269815351 INTERCHANGEABLE
Retainer,bypass Pum
Meggitt (north Hollywood), Inc. Dba Meggitt Control Systems Div Meggitt Defense Systems, Inc.
3030-01-209-502215351 INTERCHANGEABLE
Belt,v
Contitech Usa, Inc Dba Veyance Technologies
Cross-Reference Index
Part NumberManufacturer
1535-1SIZE1 1-2 Richards R W Co (USA)
1535-1 Ashcroft Inc Dba Heise (USA)
Related Parts
4920-00-010-0596INTERCHANGEABLE
PICK-UP MODIFICATIO
153-51
2920-00-350-4394INTERCHANGEABLE
GEAR
15351
4810-00-706-8004INTERCHANGEABLE
VALVE,SOLENOID
15351
4710-01-036-7552INTERCHANGEABLE
TUBE ASSEMBLY,METAL
T-8-3-635
4710-01-037-1324INTERCHANGEABLE
TUBE ASSEMBLY,METAL
15351
4530-01-047-0005INTERCHANGEABLE
JET TUBE,INLET,OIL BURNER
1045466
3020-01-155-5898INTERCHANGEABLE
SPROCKET WHEEL
14095623
4320-01-194-2698INTERCHANGEABLE
RETAINER,BYPASS PUM
15351
3030-01-209-5022INTERCHANGEABLE
BELT,V
15351

Frequently Asked Questions

What is NSN 4820-00-814-1957?

NSN 4820-00-814-1957 is a Valve,safety Relief, manufactured by Richards R W Co, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-814-1957?

NSN 4820-00-814-1957 has 2 cross-referenced part numbers: 1535-1SIZE1 1-2 (Richards R W Co), 1535-1 (Ashcroft Inc Dba Heise).

What NSN replaces 4820-00-814-1957?

There are 9 known substitutes for 4820-00-814-1957: 4920-00-010-0596, 2920-00-350-4394, 4810-00-706-8004 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 1535-1SIZE1 1-2?

Key specifications for 1535-1SIZE1 1-2: Features Provided: PRESSURE TIGHT OUTLET SIDE; Connection Type: THREADED INTERNAL PIPE ALL ENDS; Thread Direction: RIGHT-HAND ALL ENDS; Maximum Operating Temp: 200.0 FAHRENHEIT SINGLE RESPONSE DEGF. 20 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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