WATTS® 0158774 40 Series Automatic Reseating Temperature/Pressure Relief Valve, 3/4 in Nominal, MNPT x FNPT End Style, 150 psi Pressure, Bronze Body, Domestic

WA40XLI MFG #: 40XL-8-3/4
  • Body Material: Bronze
  • Country of Origin: US
  • Domestic/Import: Domestic
  • End Style: MNPT x FNPT
  • Manufacturer Name: Watts Water Technologies
  • Media: Water
  • Nominal Size: 3/4 in
  • Pressure Class: 150 lb
  • Pressure Rating: 150 psi
  • Series: 40 Series
  • Features and More


  • 8 in thermostat length
  • Non-mechanical seat-to-disc alignment
  • Thermostat is accurate and proven exclusively designed and manufactured by WATTS
  • Tamper-resistant bonnet screws
  • Series 40 and 140 feature a unique thermostat with a special thermo-bonded coating
  • The discharge line must be the same size as the valve outlet and must pitch downward from the valve and terminate at least 6 in (152 mm) above the floor drain where any discharge will be clearly visible
  • Inquire with governing authorities for local installation requirements
  • A relief valve functions in an emergency by discharging water
  • This device is designed for emergency safety relief and shall not be used as an operating control
  • For 100DT discharge line consult your WATTS agent
  • Therefore, it is essential that a discharge line be piped from the valve in order to carry the overflow to a safe place of disposal


  • Commercial Water Heater


  • ANSI Z21.22
  • ASME Section IV
  • CSA Certified
  • MIL-V-136-12D
  • SA® Certified
  • PROP65: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm.


  • Limited