PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

SK1156Valve,safety Relief

Howell Laboratories Inc Dba Howell Laboratories Inc · NSN 4820-00-446-8381 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-446-8381 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-446-8381. Primary manufacturer part number: SK1156.
Features
  • Valve,safety Relief — FSC 4820
  • Disk Loading Method: SPRING
  • Bonnet Type: INSIDE SCREW
  • Surface Treatment: ANODIZE LOCATION NOT OTHERWISE SPECIFIED
  • Material: PLASTIC POLYETHYLENE TEREPHTHALATE (PET)(POLYESTER) FLOW CONTROL DEVICE
  • Flow Control Device: BALL
  • Bonnet Attachment Method: INTEGRAL
  • Valve Operation Method: AUTOMATIC
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Plastic Polyethylene Terephthalate (pet)(polyester) Flow Control Device construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-00-446-8381, 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 8 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. 1 verified substitute exists in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-446-8381
Primary Part NumberSK1156
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerHowell Laboratories Inc Dba Howell Laboratories Inc
StatusACTIVE
Disk Loading MethodSPRING
Bonnet TypeINSIDE SCREW
Surface TreatmentANODIZE LOCATION NOT OTHERWISE SPECIFIED
MaterialPLASTIC POLYETHYLENE TEREPHTHALATE (PET)(POLYESTER) FLOW CONTROL DEVICE
Flow Control DeviceBALL
Bonnet Attachment MethodINTEGRAL
Valve Operation MethodAUTOMATIC
Surface Treatment Document and ClassificationMIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE LOCATION NOT OTHERWISE SPECIFIED
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 1
2530-00-980-32392R0487 INTERCHANGEABLE
Cylinder Assembly,air and Hydrau
Caterpillar Inc Div Caterpillar Defense
Cross-Reference Index
Part NumberManufacturer
561309 Lockheed Martin Corporation Div Rms - Mitchel Field (USA)
SK1156 PRIMARY Howell Laboratories Inc Dba Howell Laboratories Inc (USA)
Related Parts
2530-00-980-3239INTERCHANGEABLE
CYLINDER ASSEMBLY,AIR AND HYDRAU
2R0487

Frequently Asked Questions

What is NSN 4820-00-446-8381?

NSN 4820-00-446-8381 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 4820-00-446-8381?

NSN 4820-00-446-8381 has 2 cross-referenced part numbers: 561309 (Lockheed Martin Corporation Div Rms - Mitchel Field), SK1156 (Howell Laboratories Inc Dba Howell Laboratories Inc).

What NSN replaces 4820-00-446-8381?

There is 1 known substitute for 4820-00-446-8381: 2530-00-980-3239. Verify interchangeability with system specifications before substitution.

What are the specifications of SK1156?

Key specifications for SK1156: Disk Loading Method: SPRING; Bonnet Type: INSIDE SCREW; Surface Treatment: ANODIZE LOCATION NOT OTHERWISE SPECIFIED; Material: PLASTIC POLYETHYLENE TEREPHTHALATE (PET)(POLYESTER) FLOW CONTROL DEVICE. 8 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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