PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

VSS-4Valve,safety Relief

Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co. · NSN 4820-01-172-0661 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-172-0661 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-172-0661. Primary manufacturer part number: VSS-4.
Features
  • Valve,safety Relief — FSC 4820
  • Material: STEEL CORROSION RESISTING BODY
  • Thread Direction: RIGHT-HAND ALL ENDS
  • Operating Pressure: 1000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Media for Which Designed: WATER-OIL-GAS SINGLE RESPONSE
  • Thread Series Designator: NPT ALL ENDS
  • Nominal Thread Size: 0.750 INCHES ALL ENDS IN
  • Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS
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 4820-01-172-0661, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co.. Government technical data includes 16 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 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: Cancelled.

Technical Specifications
ParameterValue
NSN4820-01-172-0661
Primary Part NumberVSS-4
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerRuthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co.
StatusCANCELLED
MaterialSTEEL CORROSION RESISTING BODY
Thread DirectionRIGHT-HAND ALL ENDS
Operating Pressure1000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Media for Which DesignedWATER-OIL-GAS SINGLE RESPONSE
Thread Series DesignatorNPT ALL ENDS
Nominal Thread Size0.750 INCHES ALL ENDS IN
Connection StylePLAIN,OPTIONAL END(PIPE) ALL ENDS
Opening Pressure Setting75.0 POUNDS PER SQUARE INCH LBS
MaterialSTEEL CORROSION RESISTING FLOW CONTROL DEVICE
Style DesignatorANGLE
Valve Operation MethodAUTOMATIC
Flow Control DevicePISTON
Disk Loading MethodSPRING
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Bonnet Attachment MethodTHREADED
Bonnet TypeINSIDE SCREW
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
2540-00-102-0150300 INTERCHANGEABLE
Blade,windshield Wiper
Federal Mogul Corp Sub Wagner Brake Moog Automotive Div
5910-00-191-5778KR5D521F INTERCHANGEABLE
Capacitor,fixed,mica Dielectric
Cornell-Dubilier Marketing Inc
4320-00-218-392414345P INTERCHANGEABLE
Sleeve,shaft,pump
Curtiss-Wright Electro-Mechanical Corporation Div Epd
5310-00-225-6993 INTERCHANGEABLE
Nut,self-Locking,hexagon
5360-00-321-986010328 INTERCHANGEABLE
Spring,helical,compression
Setra Systems, Inc. Dba Gems Sensors
5999-00-481-8409 INTERCHANGEABLE
Mounting Pad,electrical-Electron
3040-00-600-3029SM-C-187062 INTERCHANGEABLE
Shaft,shouldered
Us Army Communications & Electronics Materiel Readiness Command Logistics Engineering Dir
2825-00-696-078110328 INTERCHANGEABLE
Valve Head
Northrop Grumman Systems Corporation Div Marine Systems
5133-01-018-9814 INTERCHANGEABLE
Drill,twist
6145-01-292-5230MIS-20054/19-001 INTERCHANGEABLE
Cable,special Purpose,electrical
Us Army Aviation and Missile Command
Cross-Reference Index
Part NumberManufacturer
VSS-4 Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co. (USA)
22M3-105 Ellis & Watts International, Llc (USA)
10328 Electro Impulse Laboratory Inc Dba Electro Impulse Inc (USA)
Related Parts
2540-00-102-0150INTERCHANGEABLE
BLADE,WINDSHIELD WIPER
300
5910-00-191-5778INTERCHANGEABLE
CAPACITOR,FIXED,MICA DIELECTRIC
KR5D521F
4320-00-218-3924INTERCHANGEABLE
SLEEVE,SHAFT,PUMP
14345P
5310-00-225-6993INTERCHANGEABLE
NUT,SELF-LOCKING,HEXAGON
5360-00-321-9860INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
10328
5999-00-481-8409INTERCHANGEABLE
MOUNTING PAD,ELECTRICAL-ELECTRON
3040-00-600-3029INTERCHANGEABLE
SHAFT,SHOULDERED
SM-C-187062
2825-00-696-0781INTERCHANGEABLE
VALVE HEAD
10328
5133-01-018-9814INTERCHANGEABLE
DRILL,TWIST
6145-01-292-5230INTERCHANGEABLE
CABLE,SPECIAL PURPOSE,ELECTRICAL
MIS-20054/19-001
4720-01-457-9058INTERCHANGEABLE
HOSE ASSEMBLY,NONMETALLIC
8415-01-468-6900INTERCHANGEABLE
WEATHER COVER
10328

Frequently Asked Questions

What is NSN 4820-01-172-0661?

NSN 4820-01-172-0661 is a Valve,safety Relief, manufactured by Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co., classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-01-172-0661?

NSN 4820-01-172-0661 has 3 cross-referenced part numbers: VSS-4 (Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co.), 22M3-105 (Ellis & Watts International, Llc), 10328 (Electro Impulse Laboratory Inc Dba Electro Impulse Inc).

What NSN replaces 4820-01-172-0661?

There are 12 known substitutes for 4820-01-172-0661: 2540-00-102-0150, 5910-00-191-5778, 4320-00-218-3924 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of VSS-4?

Key specifications for VSS-4: Material: STEEL CORROSION RESISTING BODY; Thread Direction: RIGHT-HAND ALL ENDS; Operating Pressure: 1000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS; Media for Which Designed: WATER-OIL-GAS SINGLE RESPONSE. 16 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-01-172-0661 still in active supply?

NSN 4820-01-172-0661 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com