PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

20126AS51SSValve,safety Relief

Anderson Greenwood Lp Dba Anderson Greenwood Crosby · NSN 4820-00-495-2570 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-495-2570 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-495-2570. Primary manufacturer part number: 20126AS51SS.
Features
  • Valve,safety Relief — FSC 4820
  • Maximum Operating Temp: 650.0 FAHRENHEIT SINGLE RESPONSE DEGF
  • Material: COBALT ALLOY FLOW CONTROL DEVICE
  • Connection Type: FLANGE FIRST END
  • Criticality Code Justification: ZZZY
  • Style Designator: ANGLE
  • Operating Pressure: 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Opening Pressure Setting: 2485.0 POUNDS PER SQUARE INCH LBS
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Cobalt Alloy Flow Control Device construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-495-2570, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Anderson Greenwood Lp Dba Anderson Greenwood Crosby. Government technical data includes 22 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4820-00-495-2570
Primary Part Number20126AS51SS
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerAnderson Greenwood Lp Dba Anderson Greenwood Crosby
StatusCANCELLED
Maximum Operating Temp650.0 FAHRENHEIT SINGLE RESPONSE DEGF
MaterialCOBALT ALLOY FLOW CONTROL DEVICE
Connection TypeFLANGE FIRST END
Criticality Code JustificationZZZY
Style DesignatorANGLE
Operating Pressure3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Opening Pressure Setting2485.0 POUNDS PER SQUARE INCH LBS
Adjustable Pressure Range+2401.0 TO 3000.0 POUNDS PER SQUARE INCH LBS
Valve Discharge Flow Rate74.0 GALLONS PER MINUTE
MaterialSTEEL COMP 303 BODY LINING
Media for Which DesignedWATER, FRESH SINGLE RESPONSE
Flow Control DeviceDISK
Bonnet Attachment MethodBOLTED
MaterialSTEEL COMP 303 PACKING
Reference Number Differentiating CharacteristicsMATERIAL WILL BE IN ACCORDANCE WITH SHIPS PARTS CONTROL CENTER ACTIVITY HX QUALITY CONTROL,MANUFACTURING AND TESTING SPECIFICATIONS
Flange Face DesignRAISED STRAIGHT FIRST END
Renewable Seat Ring TypeTHREADED
Features ProvidedVALVE STEM LOCK SHIELD AND PRESSURE TIGHT OUTLET SIDE
Valve Operation MethodAUTOMATIC
Bonnet TypeINSIDE SPRING
Disk Loading MethodSPRING
Flange ShapeROUND FIRST END
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 9
6850-00-155-644476759 INTERCHANGEABLE
Chemical Antigalling Cmpd
Loctite Corp
5133-00-228-1375 INTERCHANGEABLE
Drill,twist
5895-00-342-9460A15642 INTERCHANGEABLE
Gate,electronic
Bae Systems Information and Electronic Systems Integration Inc.
5365-00-474-307220126 INTERCHANGEABLE
Plug,machine Thread
Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney
6145-01-087-9773 INTERCHANGEABLE
Cable,special Purpose,electrical
5935-01-188-73409355715 INTERCHANGEABLE
Connector Assembly,electrical
Combat Capabilities Development Command (ccdc) Armaments Center Dba Ccdc Div Logistics Research and Engineering Directorate
4920-01-299-028120126 INTERCHANGEABLE
Test Program Set
Textron Systems Corporation Dba Textron Systems Corp
4330-01-346-7650RK 22838 INTERCHANGEABLE
Plug,probe
Parker-Hannifin Corporation Dba Racor Division Div Racor Division
5306-01-685-003020-126-16-55 INTERCHANGEABLE
Bolt,machine
Bell Textron Inc
Cross-Reference Index
Part NumberManufacturer
20126AS51SS Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA)
A15642 Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA)
20126 Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA)
Related Parts
6850-00-155-6444INTERCHANGEABLE
CHEMICAL ANTIGALLING CMPD
76759
5133-00-228-1375INTERCHANGEABLE
DRILL,TWIST
5895-00-342-9460INTERCHANGEABLE
GATE,ELECTRONIC
A15642
5365-00-474-3072INTERCHANGEABLE
PLUG,MACHINE THREAD
20126
6145-01-087-9773INTERCHANGEABLE
CABLE,SPECIAL PURPOSE,ELECTRICAL
5935-01-188-7340INTERCHANGEABLE
CONNECTOR ASSEMBLY,ELECTRICAL
9355715
4920-01-299-0281INTERCHANGEABLE
TEST PROGRAM SET
20126
4330-01-346-7650INTERCHANGEABLE
PLUG,PROBE
RK 22838
5306-01-685-0030INTERCHANGEABLE
BOLT,MACHINE
20-126-16-55

Frequently Asked Questions

What is NSN 4820-00-495-2570?

NSN 4820-00-495-2570 is a Valve,safety Relief, manufactured by Anderson Greenwood Lp Dba Anderson Greenwood Crosby, classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-00-495-2570?

NSN 4820-00-495-2570 has 3 cross-referenced part numbers: 20126AS51SS (Anderson Greenwood Lp Dba Anderson Greenwood Crosby), A15642 (Anderson Greenwood Lp Dba Anderson Greenwood Crosby), 20126 (Anderson Greenwood Lp Dba Anderson Greenwood Crosby).

What NSN replaces 4820-00-495-2570?

There are 9 known substitutes for 4820-00-495-2570: 6850-00-155-6444, 5133-00-228-1375, 5895-00-342-9460 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 20126AS51SS?

Key specifications for 20126AS51SS: Maximum Operating Temp: 650.0 FAHRENHEIT SINGLE RESPONSE DEGF; Material: COBALT ALLOY FLOW CONTROL DEVICE; Connection Type: FLANGE FIRST END; Criticality Code Justification: ZZZY. 22 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-00-495-2570 still in active supply?

NSN 4820-00-495-2570 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