PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

4875-G503Valve,safety Relief

Howell Laboratories Inc Dba Howell Laboratories Inc · NSN 4820-01-259-8777 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-259-8777 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-259-8777. Primary manufacturer part number: 4875-G503.
Features
  • Valve,safety Relief — FSC 4820
  • Nominal Thread Size: 1.000 INCHES ALL ENDS IN
  • Material: STEEL CORROSION RESISTING BODY
  • Flow Control Device: PISTON
  • Connection Style: PLAIN (PIPE) ALL ENDS
  • Thread Series Designator: NPT ALL ENDS
  • Adjustable Pressure Range: +6.0 TO 14.0 POUNDS PER SQUARE INCH LBS
  • Style Designator: STRAIGHT THRU
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Corrosion Resisting Body construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-01-259-8777, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Howell Laboratories Inc Dba Howell Laboratories Inc. Government technical data includes 10 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 6 commercial cross-references from 3 manufacturers, 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
NSN4820-01-259-8777
Primary Part Number4875-G503
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerHowell Laboratories Inc Dba Howell Laboratories Inc
StatusACTIVE
Nominal Thread Size1.000 INCHES ALL ENDS IN
MaterialSTEEL CORROSION RESISTING BODY
Flow Control DevicePISTON
Connection StylePLAIN (PIPE) ALL ENDS
Thread Series DesignatorNPT ALL ENDS
Adjustable Pressure Range+6.0 TO 14.0 POUNDS PER SQUARE INCH LBS
Style DesignatorSTRAIGHT THRU
Valve Operation MethodAUTOMATIC
Connection TypeTHREADED EXTERNAL PIPE ALL ENDS
Thread DirectionRIGHT-HAND ALL ENDS
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5940-00-143-4780MS25036-108 INTERCHANGEABLE
Terminal,lug
Sae International Dba Sae International
4320-00-585-77704875 INTERCHANGEABLE
Pump Unit,centrifugal
E C Schleyer Pump Co Inc
5940-00-617-24302-34161-1 INTERCHANGEABLE
Terminal,lug
Te Connectivity Corporation
3040-00-671-1582487-5 INTERCHANGEABLE
Gearshaft,worm Wheel
Mas Components & Coatings, Llc Dba Mas Components & Coatings Llc
5330-01-037-87734875-5 INTERCHANGEABLE
Packing
Coffin Turbo Pump Inc
5120-01-073-6240GS15913-1 INTERCHANGEABLE
Inserter,bearing and Bushing
Hamilton Sundstrand Corporation Dba Collins Aerospace
5961-01-100-3465 INTERCHANGEABLE
Mounting Kit
5340-01-141-5484 INTERCHANGEABLE
Hardware Kit,electronic Equipmen
5915-01-204-10771603976 INTERCHANGEABLE
Filter,low Pass
Lockheed Martin Corporation Div Rms - Mitchel Field
2540-01-397-86464875 INTERCHANGEABLE
Latch,door,vehicular
Isometrics Inc
Cross-Reference Index
Part NumberManufacturer
4875C-G503 Howell Laboratories Inc Dba Howell Laboratories Inc (USA)
4875C-G503 Lindco-Springfield, Inc Dba Lindco Controls Div (USA)
4875-G503 PRIMARY Howell Laboratories Inc Dba Howell Laboratories Inc (USA)
4875 Lindco-Springfield, Inc Dba Lindco Controls Div (USA)
4875 Howell Laboratories Inc Dba Howell Laboratories Inc (USA)
X559T1-8M-10 Circor Aerospace, Inc. Dba Circor Aerospace Inc (USA)
Related Parts
5940-00-143-4780INTERCHANGEABLE
TERMINAL,LUG
MS25036-108
4320-00-585-7770INTERCHANGEABLE
PUMP UNIT,CENTRIFUGAL
4875
5940-00-617-2430INTERCHANGEABLE
TERMINAL,LUG
2-34161-1
3040-00-671-1582INTERCHANGEABLE
GEARSHAFT,WORM WHEEL
487-5
5330-01-037-8773INTERCHANGEABLE
PACKING
4875-5
5120-01-073-6240INTERCHANGEABLE
INSERTER,BEARING AND BUSHING
GS15913-1
5961-01-100-3465INTERCHANGEABLE
MOUNTING KIT
5340-01-141-5484INTERCHANGEABLE
HARDWARE KIT,ELECTRONIC EQUIPMEN
5915-01-204-1077INTERCHANGEABLE
FILTER,LOW PASS
1603976
2540-01-397-8646INTERCHANGEABLE
LATCH,DOOR,VEHICULAR
4875
2530-01-420-5572INTERCHANGEABLE
HUB,WHEEL,VEHICULAR
4820-01-443-9866INTERCHANGEABLE
VALVE,SAFETY RELIEF
D559T1-8M-1

Frequently Asked Questions

What is NSN 4820-01-259-8777?

NSN 4820-01-259-8777 is a Valve,safety Relief, manufactured by Howell Laboratories Inc Dba Howell Laboratories Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-259-8777?

NSN 4820-01-259-8777 has 6 cross-referenced part numbers: 4875C-G503 (Howell Laboratories Inc Dba Howell Laboratories Inc), 4875C-G503 (Lindco-Springfield, Inc Dba Lindco Controls Div), 4875-G503 (Howell Laboratories Inc Dba Howell Laboratories Inc), 4875 (Lindco-Springfield, Inc Dba Lindco Controls Div), 4875 (Howell Laboratories Inc Dba Howell Laboratories Inc) and 1 more.

What NSN replaces 4820-01-259-8777?

There are 12 known substitutes for 4820-01-259-8777: 5940-00-143-4780, 4320-00-585-7770, 5940-00-617-2430 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 4875-G503?

Key specifications for 4875-G503: Nominal Thread Size: 1.000 INCHES ALL ENDS IN; Material: STEEL CORROSION RESISTING BODY; Flow Control Device: PISTON; Connection Style: PLAIN (PIPE) ALL ENDS. 10 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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