PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

559B-2M-15Valve,safety Relief

Circor Aerospace, Inc. Dba Circor Aerospace Inc · NSN 4820-00-976-0348 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-976-0348 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-976-0348. Primary manufacturer part number: 559B-2M-15.
Features
  • Valve,safety Relief — FSC 4820
  • Disk Loading Method: SPRING
  • Connection Style: PLAIN (PIPE) FIRST END
  • Media for Which Designed: AMMONIA, LIQUID THIRD RESPONSE
  • Media for Which Designed: AIR SECOND RESPONSE
  • Media for Which Designed: ACETYLENE FIRST RESPONSE
  • Thread Direction: RIGHT-HAND FIRST END
  • Media for Which Designed: GAS, INERT FOURTH RESPONSE
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 4820-00-976-0348, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Circor Aerospace, Inc. Dba Circor Aerospace Inc. Government technical data includes 19 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 6 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-976-0348
Primary Part Number559B-2M-15
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerCircor Aerospace, Inc. Dba Circor Aerospace Inc
StatusACTIVE
Disk Loading MethodSPRING
Connection StylePLAIN (PIPE) FIRST END
Media for Which DesignedAMMONIA, LIQUID THIRD RESPONSE
Media for Which DesignedAIR SECOND RESPONSE
Media for Which DesignedACETYLENE FIRST RESPONSE
Thread DirectionRIGHT-HAND FIRST END
Media for Which DesignedGAS, INERT FOURTH RESPONSE
Connection TypeTHREADED EXTERNAL PIPE FIRST END
Media for Which DesignedHYDROGEN FIFTH RESPONSE
Style DesignatorSTRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY.
MaterialCOPPER ALLOY OVERALL
Flow Control DevicePOPPET
Valve Operation MethodAUTOMATIC
Surface TreatmentCHROMIUM LOCATION NOT OTHERWISE SPECIFIED
Nominal Thread Size0.250 INCHES FIRST END IN
Operating Pressure200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Opening Pressure Setting15.0 POUNDS PER SQUARE INCH LBS
Thread Series DesignatorNPT FIRST END
Maximum Operating Temp250.0 FAHRENHEIT SINGLE RESPONSE DEGF
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 6
5360-00-084-335011779 INTERCHANGEABLE
Spring,helical,compression
Setra Systems, Inc. Dba Gems Sensors
3040-00-110-831411779 INTERCHANGEABLE
Cylinder Assembly,actuating,line
Terex Reedrill Dba Reedrill Texoma Div Terex Mining
4720-00-450-91561503-16 INTERCHANGEABLE
Hose,nonmetallic
Danfoss Power Solutions II, Llc
4820-01-056-3600559B-6M-35 INTERCHANGEABLE
Valve,safety Relief
Circor Aerospace, Inc. Dba Circor Aerospace Inc
5330-01-389-008611779 INTERCHANGEABLE
Gasket
Clemco Industries Corp. Dba Clemco Industries Corp Div Clemco
4720-01-619-361111779 INTERCHANGEABLE
Hose,nonmetallic
Westerbeke Corporation
Cross-Reference Index
Part NumberManufacturer
559B-2M-15 PRIMARY Circor Aerospace, Inc. Dba Circor Aerospace Inc (USA)
11779 Spx Corporation Dba Dielectric Communications Div Spx Communication Technologies (USA)
11779 PT NO. 12 Spx Corporation Dba Dielectric Communications Div Spx Communication Technologies (USA)
Related Parts
5360-00-084-3350INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
11779
3040-00-110-8314INTERCHANGEABLE
CYLINDER ASSEMBLY,ACTUATING,LINE
11779
4720-00-450-9156INTERCHANGEABLE
HOSE,NONMETALLIC
1503-16
4820-01-056-3600INTERCHANGEABLE
VALVE,SAFETY RELIEF
559B-6M-35
5330-01-389-0086INTERCHANGEABLE
GASKET
11779
4720-01-619-3611INTERCHANGEABLE
HOSE,NONMETALLIC
11779

Frequently Asked Questions

What is NSN 4820-00-976-0348?

NSN 4820-00-976-0348 is a Valve,safety Relief, manufactured by Circor Aerospace, Inc. Dba Circor Aerospace Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-976-0348?

NSN 4820-00-976-0348 has 3 cross-referenced part numbers: 559B-2M-15 (Circor Aerospace, Inc. Dba Circor Aerospace Inc), 11779 (Spx Corporation Dba Dielectric Communications Div Spx Communication Technologies), 11779 PT NO. 12 (Spx Corporation Dba Dielectric Communications Div Spx Communication Technologies).

What NSN replaces 4820-00-976-0348?

There are 6 known substitutes for 4820-00-976-0348: 5360-00-084-3350, 3040-00-110-8314, 4720-00-450-9156 and 3 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 559B-2M-15?

Key specifications for 559B-2M-15: Disk Loading Method: SPRING; Connection Style: PLAIN (PIPE) FIRST END; Media for Which Designed: AMMONIA, LIQUID THIRD RESPONSE; Media for Which Designed: AIR SECOND RESPONSE. 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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