Secure Ordering: +1 (757) 528-8028

Worldwide distributor of NSN parts and consumables located in the USA.

Safety Relief Valve

NSN: 4820-00-163-5161 | Model: A42437
ITAR Registered seal

A valve designed to automatically release excessive pressures. It is actuated by static pressure upstream of the valve and is used as a safety valve or relief valve, and may be set to close at a predetermined pressure. It is not designed for regulation of continuously fluctuating loads. It may be inline or cartridge (manifold) design. Excludes valve (1), relief, pressure and temperature.

NSN Properties and Flags
NATO Stock Number
Yes - ITAR Controlled
Flow Control Device
Bonnet Type
Exposed spring
Bonnet Attachment Method
Disk Loading Method
Valve Discharge Flow Rate
43200.0 pounds per hour
Renewable Seat Ring Type
Bolt Hole Quantity
8 2ND end
Valve Operation Method
Automatic or manual
Flange Shape
Round with holes 2ND end
Features Provided
Pressure tight outlet side
Valve Size
2.500 inches
Criticality Code Justification
Opening Pressure Setting
710.0 pounds per square inch
Outside Diameter
9.000 inches 2ND end
1.250 inches 1ST end
Bolt Hole Diameter
0.875 inches 2ND end
Bolt Circle Diameter
7.250 inches 2ND end
Flange Face Design
Recessed straight 1ST end
Raised Face Height
0.062 inches 2ND end
Raised Face Diameter
5.500 inches 2ND end
Recess Diameter
6.875 inches 1ST end
Recess Depth
0.062 inches 1ST end
Special Features
Items are being coded as critical to insure source inspection will be performed at the point of manufacture, prior to material receipt by the us navy or other dod components. These items are piece parts or end items in support of vital military hardware necessary to sustain the successful mission of the ships, submarines, and shore stations of the us navy. Critical features including, but not limited to, dimensions, tolerances/clearances, electronic characteristics, and metallurgical properties will bespecified for government q ar (quality assurance representatives) to insure the highest possible degree of quality and reliability of these parts being delivered under navicp contracts
Style Designator
Angle flanked ends
Reference Number Differentiating Characteristics
As differentiated by the valve discharge flow rate requirement

Pricing and Availability

Send us a request for quote using the form below. Our team will contact you with an up to date pricing and availability quote ASAP.

Email Address:
Phone Number:
Your name:
Privacy    Terms

Certified Quality Assurance  Quality check icon

  •   ISO 9001:2015 + AS9120B
  •   Counterfeit Parts Prevention
  •   100% Product Inspections
  •   7 Year Record Retention
  •   On Time Delivery
  •   HAZMAT Certified
  •   Worldwide Shipping

NSN 4820-00-163-5161 Datasheet

Supply Class (FSC):
Nonpowered Valves
Cross Reference:
  • A42437
Cage Codes:
  • Pentair Valves & Controls Us Lp (CAGE 15187)
Schedule B & Trade:
  • Schedule B: 8481400000 (NAICS 332911)

    Safety or relief valves

  • SITC: 74740

    Safety or relief valves

  • End Use: 21180

    Industrial machines, other


N - Indicates there is no data in the humors and the nsn is in a fsc not generally suspected of containing hazardous materials.


A - Item does not contain precious metal.


- Represents items with no adp components


- The item does not have a nuclear hardened feature but does have other critical feature (s) such as tolerance, fit restrictions or application.

Freight Information:
  • NMFC:

    127220 - Pressure reg/red/relief valves noi

  • WCC:

    594 - Pumps and parts, (machinery and parts),(less than 35 feet)

  • SHC:

    9 - Other or no special handling required (sh)

  • ADC:

    A - Shipment is not a consolidation and does not exceed 84 inches in any dimension.

  • LCL:

    P - 77.5

  • LTL:

    P - 77.5

  • ACC:

    V - Trailers, vehicles, machinery, shop and warehouse equipment and supplies including special tools and equipment, ground servicing

  • TCC:

    Z - No special type of cargo code applicable

NSN Management Codes:
  • SOS
  • AAC
  • Quantity per pack
    No qup
  • Unit of Measure
  • Shelf Life
  • Classification Control
  • Repariability
    If condemned or uneconomically repairable, then dispose at intermediate level.

Questions & Answers:

What are the historical prices recorded for this stock number?
Historical data shows pricing from $8,486.40 to $14,144.00..
Does NSN 4820-00-163-5161 have a shelf life?
No. There is no shelf life applicable for this NSN.
What NATO entities are users of this NSN?
Department Of The Navy
What is the NIIN of NSN 4820-00-163-5161?
001635161 or 00-163-5161
Does NSN 4820-00-163-5161 require demilitarization?
Yes - ITAR Controlled
What is the most recent solicitation for NSN 4820-00-163-5161?
No solicitations for this NSN.
When was this national stock number assigned to the federal catalog?
Nov 13, 1971