PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

40XL-3/4IN.100PSIValve,relief,pressure and Temper

Watts Regulator Company · NSN 4820-00-849-9731 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-849-9731 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-849-9731. Primary manufacturer part number: 40XL-3/4IN.100PSI.
Features
  • Valve,relief,pressure and Temper — FSC 4820
  • Material: PLASTIC SILICONE FLOW CONTROL DEVICE
  • Flow Control Device: POPPET
  • Second End Nominal Pipe Size Accommodated: 0.750 INCHES IN
  • Second End Relationship with First End: NOT IDENTICAL
  • First End Thread Series Designator: NPT
  • Temp Adjustability: NOT ADJUSTABLE
  • Opening Pressure Setting: ERR-060
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Plastic Silicone Flow Control Device construction
General Description

The Valve,relief,pressure and Temper, cataloged under National Stock Number 4820-00-849-9731, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Watts Regulator Company. Government technical data includes 26 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 1 manufacturer, 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
NSN4820-00-849-9731
Primary Part Number40XL-3/4IN.100PSI
Item NameValve,relief,pressure and Temper
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerWatts Regulator Company
StatusACTIVE
MaterialPLASTIC SILICONE FLOW CONTROL DEVICE
Flow Control DevicePOPPET
Second End Nominal Pipe Size Accommodated0.750 INCHES IN
Second End Relationship with First EndNOT IDENTICAL
First End Thread Series DesignatorNPT
Temp AdjustabilityNOT ADJUSTABLE
Opening Pressure SettingERR-060
Bulb Length5.750 INCHES NOMINAL IN
Second End Connection TypeTHREADED EXTERNAL PIPE
End Connection Quantity2
Second End Thread DirectionRIGHT-HAND
Body StyleANGLE GIVE "ADQM" AND "ADQN" ONLY IF FLANGED ONE OR TWO ENDS
Temp Control Device TypeTHERMOSTATIC
First End Nominal Pipe Size Accommodated0.750 INCHES IN
Furnished ItemsEMERGENCY OPENING DEVICE
Second End Thread Series DesignatorNPT
First End Style DesignatorPLAIN
First End Nominal Thread Size0.750 INCHES IN
MaterialCOPPER ALLOY BODY
MaterialCOPPER ALLOY STEM
First End Connection TypeTHREADED INTERNAL PIPE
Second End Nominal Thread Size0.750 INCHES IN
First End Thread DirectionRIGHT-HAND
Second End Style DesignatorPLAIN
Media for Which DesignedWATER, FRESH
Temp Rating210.0 FAHRENHEIT DEGF
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4820-00-541-883940XL-3/4-75PSI INTERCHANGEABLE
Valve,relief,pressure and Temper
Watts Regulator Company
4820-00-855-6169 INTERCHANGEABLE
Valve,relief,pressure and Temper
2590-01-394-969740XL INTERCHANGEABLE
Cap,filler Opening
Lenz Co
Cross-Reference Index
Part NumberManufacturer
40XL Watts Regulator Company (USA)
40XL-3/4IN.90PSI Watts Regulator Company (USA)
40XL-3/4IN.100PSI PRIMARY Watts Regulator Company (USA)
Related Parts
4820-00-541-8839INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
40XL-3/4-75PSI
4820-00-855-6169INTERCHANGEABLE
VALVE,RELIEF,PRESSURE AND TEMPER
2590-01-394-9697INTERCHANGEABLE
CAP,FILLER OPENING
40XL

Frequently Asked Questions

What is NSN 4820-00-849-9731?

NSN 4820-00-849-9731 is a Valve,relief,pressure and Temper, manufactured by Watts Regulator Company, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-849-9731?

NSN 4820-00-849-9731 has 3 cross-referenced part numbers: 40XL (Watts Regulator Company), 40XL-3/4IN.90PSI (Watts Regulator Company), 40XL-3/4IN.100PSI (Watts Regulator Company).

What NSN replaces 4820-00-849-9731?

There are 3 known substitutes for 4820-00-849-9731: 4820-00-541-8839, 4820-00-855-6169, 2590-01-394-9697. Verify interchangeability with system specifications before substitution.

What are the specifications of 40XL-3/4IN.100PSI?

Key specifications for 40XL-3/4IN.100PSI: Material: PLASTIC SILICONE FLOW CONTROL DEVICE; Flow Control Device: POPPET; Second End Nominal Pipe Size Accommodated: 0.750 INCHES IN; Special Features: 130.000 BTU PER HR MIN DISCHARGE. 27 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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