PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

18C-402-27Valve,relief,pressure and Temper

Aalberts Integrated Piping Systems Americas, Inc. · NSN 4820-00-632-1521 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-632-1521 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-632-1521. Primary manufacturer part number: 18C-402-27.
Features
  • Valve,relief,pressure and Temper — FSC 4820
  • Second End Nominal Pipe Size Accommodated: 0.750 INCHES IN
  • Second End Connection Type: THREADED EXTERNAL PIPE
  • End Connection Quantity: 2
  • Material: COPPER ALLOY SEAT
  • Flow Control Device: POPPET
  • Temp Adjustability: NOT ADJUSTABLE
  • Second End Style Designator: PLAIN
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Copper Alloy Seat construction
General Description

The Valve,relief,pressure and Temper, cataloged under National Stock Number 4820-00-632-1521, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Aalberts Integrated Piping Systems Americas, Inc.. Government technical data includes 22 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 8 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4820-00-632-1521
Primary Part Number18C-402-27
Item NameValve,relief,pressure and Temper
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerAalberts Integrated Piping Systems Americas, Inc.
StatusCANCELLED
Second End Nominal Pipe Size Accommodated0.750 INCHES IN
Second End Connection TypeTHREADED EXTERNAL PIPE
End Connection Quantity2
MaterialCOPPER ALLOY SEAT
Flow Control DevicePOPPET
Temp AdjustabilityNOT ADJUSTABLE
Second End Style DesignatorPLAIN
Furnished ItemsEMERGENCY OPENING DEVICE
Temp Control Device TypeTHERMOSTATIC
MaterialPLASTIC SILICONE FLOW CONTROL DEVICE
First End Thread DirectionRIGHT-HAND
Second End Thread DirectionRIGHT-HAND
MaterialCOPPER ALLOY BODY
Body StyleANGLE GIVE "ADQM" AND "ADQN" ONLY IF FLANGED ONE OR TWO ENDS
Temp Rating210.0 FAHRENHEIT DEGF
MaterialCOPPER ALLOY STEM
Second End Relationship with First EndNOT IDENTICAL
First End Connection TypeTHREADED INTERNAL PIPE
First End Style DesignatorPLAIN
Media for Which DesignedWATER, FRESH
Opening Pressure SettingERR-060
First End Nominal Pipe Size Accommodated0.750 INCHES IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 8
4820-00-142-3190N240-X-1IN INTERCHANGEABLE
Valve,relief,pressure and Temper
Watts Regulator Company
6220-00-299-682108242X INTERCHANGEABLE
Stop Light-Taillight,vehicular
Abm Equipment, Llc
5961-00-608-0501 INTERCHANGEABLE
Semiconductor Device,diode
4820-00-855-6169 INTERCHANGEABLE
Valve,relief,pressure and Temper
4820-00-913-311540L-3150PSI INTERCHANGEABLE
Valve,relief,pressure and Temper
Watts Regulator Company
4820-01-061-533817737-7-11-D INTERCHANGEABLE
Valve,relief,pressure and Temper
The Electric Heater Co Dba Hubbell Electric Heater Co.
4240-01-421-3662SPEC40L INTERCHANGEABLE
Mask,air Line
E. D. Bullard Company Dba Ed Bullard Co
1005-01-560-601940L INTERCHANGEABLE
Sight,grenade Launcher
Samson Mfg Co
Cross-Reference Index
Part NumberManufacturer
18C-402-27 PRIMARY Aalberts Integrated Piping Systems Americas, Inc. (USA)
40L PRIMARY Watts Regulator Company (USA)
401X Smith a O Corp Consumer Products Div (USA)
40L3-4 Watts Regulator Company (USA)
ANSI Z21.22 American National Standards Institute Incorporated Dba American National Standards Institute (USA)
MILV13612 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
18-302-09 Aalberts Integrated Piping Systems Americas, Inc. (USA)
18-402-27 Aalberts Integrated Piping Systems Americas, Inc. (USA)
Related Parts
4820-00-142-3190INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
N240-X-1IN
6220-00-299-6821INTERCHANGEABLE
STOP LIGHT-TAILLIGHT,VEHICULAR
08242X
5961-00-608-0501INTERCHANGEABLE
SEMICONDUCTOR DEVICE,DIODE
4820-00-855-6169INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
4820-00-913-3115INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
40L-3150PSI
4820-01-061-5338INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
17737-7-11-D
4240-01-421-3662INTERCHANGEABLE
MASK,AIR LINE
SPEC40L
1005-01-560-6019INTERCHANGEABLE
SIGHT,GRENADE LAUNCHER
40L

Frequently Asked Questions

What is NSN 4820-00-632-1521?

NSN 4820-00-632-1521 is a Valve,relief,pressure and Temper, manufactured by Aalberts Integrated Piping Systems Americas, Inc., classified under FSC 4820 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4820-00-632-1521?

NSN 4820-00-632-1521 has 8 cross-referenced part numbers: 18C-402-27 (Aalberts Integrated Piping Systems Americas, Inc.), 40L (Watts Regulator Company), 401X (Smith a O Corp Consumer Products Div), 40L3-4 (Watts Regulator Company), ANSI Z21.22 (American National Standards Institute Incorporated Dba American National Standards Institute) and 3 more.

What NSN replaces 4820-00-632-1521?

There are 8 known substitutes for 4820-00-632-1521: 4820-00-142-3190, 6220-00-299-6821, 5961-00-608-0501 and 5 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 18C-402-27?

Key specifications for 18C-402-27: Second End Nominal Pipe Size Accommodated: 0.750 INCHES IN; Second End Connection Type: THREADED EXTERNAL PIPE; End Connection Quantity: 2; Material: COPPER ALLOY SEAT. 23 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4820-00-632-1521 still in active supply?

NSN 4820-00-632-1521 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.
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