PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

A6567Valve,safety Relief

Stewart Avionics Inc · NSN 4820-00-780-6877 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-780-6877 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-780-6877. Primary manufacturer part number: A6567.
Features
  • Valve,safety Relief — FSC 4820
  • Thread Direction: RIGHT-HAND SECOND END
  • Nominal Thread Size: 0.250 INCHES SECOND END IN
  • Thread Direction: RIGHT-HAND FIRST END
  • Thread Series Designator: NPTF FIRST END
  • Nominal Thread Size: 0.375 INCHES FIRST END IN
  • Thread Quantity Per Inch: 18 SECOND END
  • Thread Series Designator: NPTF SECOND END
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-780-6877, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Stewart Avionics Inc. Government technical data includes 14 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. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-780-6877
Primary Part NumberA6567
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerStewart Avionics Inc
StatusACTIVE
Thread DirectionRIGHT-HAND SECOND END
Nominal Thread Size0.250 INCHES SECOND END IN
Thread DirectionRIGHT-HAND FIRST END
Thread Series DesignatorNPTF FIRST END
Nominal Thread Size0.375 INCHES FIRST END IN
Thread Quantity Per Inch18 SECOND END
Thread Series DesignatorNPTF SECOND END
Connection StylePLAIN,OPTIONAL END(PIPE) SECOND END
Connection TypeTHREADED INTERNAL PIPE SECOND END
Style DesignatorANGLE
Nominal Pipe Size Accommodated0.375 INCHES FIRST END IN
Connection TypeTHREADED INTERNAL PIPE FIRST END
Nominal Pipe Size Accommodated0.250 INCHES SECOND END IN
Thread Quantity Per Inch18 FIRST END
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
5930-00-777-2285A6567 INTERCHANGEABLE
Plate,switch
Simmonds Precision Products Inc
2520-00-931-4638A6567C INTERCHANGEABLE
Disk,clutch,vehicular
Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic
5310-01-149-9548A-6578 INTERCHANGEABLE
Nut
Anderson Greenwood Lp Dba Anderson Greenwood Crosby
Cross-Reference Index
Part NumberManufacturer
A6567 PRIMARY Stewart Avionics Inc (USA)
A6567 Metadure Parts & Sales, Inc. (USA)
Related Parts
5930-00-777-2285INTERCHANGEABLE
PLATE,SWITCH
A6567
2520-00-931-4638INTERCHANGEABLE
DISK,CLUTCH,VEHICULAR
A6567C
5310-01-149-9548INTERCHANGEABLE
NUT
A-6578

Frequently Asked Questions

What is NSN 4820-00-780-6877?

NSN 4820-00-780-6877 is a Valve,safety Relief, manufactured by Stewart Avionics Inc, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-780-6877?

NSN 4820-00-780-6877 has 2 cross-referenced part numbers: A6567 (Stewart Avionics Inc), A6567 (Metadure Parts & Sales, Inc.).

What NSN replaces 4820-00-780-6877?

There are 3 known substitutes for 4820-00-780-6877: 5930-00-777-2285, 2520-00-931-4638, 5310-01-149-9548. Verify interchangeability with system specifications before substitution.

What are the specifications of A6567?

Key specifications for A6567: Thread Direction: RIGHT-HAND SECOND END; Nominal Thread Size: 0.250 INCHES SECOND END IN; Thread Direction: RIGHT-HAND FIRST END; Thread Series Designator: NPTF FIRST END. 14 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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