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  • D-040 L | Combination Air Valve for Small Suspended Solids for Low-Pressure Systems

D-040 L | Combination Air Valve for Small Suspended Solids for Low-Pressure Systems


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  • Product Drawings:
  • Install & Maintenance:
  • Install & Maintenance (2):
150 PSI / 250 PSI


The D-040 L Combination Air Valve has the features of both an air release valve and an air & vacuum valve in a single body. This air valve is specifically designed to operate with liquids containing small suspended solids.
The air release component is designed to automatically release small pockets of air to the atmosphere as they accumulate along a pipeline or piping system when it is full and operating under pressure.
The air & vacuum component is designed to automatically discharge or admit large volumes of air during the filling or draining of a pipeline or piping system. This air valve will open to relieve negative pressures whenever water column separation occurs.
The valve’s unique design enables the separation of the liquid from the sealing mechanism and assures optimum working conditions.

Product Features

  • The valve's rolling seal mechanism design enables a one size orifice for a wide pressure range:
    Polypropylenene : 3 – 150 PSI
    Reinforced Nylon / PVDF: 0.7 – 250 PSI
    St.St. 316 /Duplex :0.7 -250 PSI
  • Dynamic design allows for high velocity air discharge while preventing premature closure.
  • Builds an air gap that separates the liquids with suspended particles from the sealing mechanism.

Materials and Corrosion Protection

  • The body is made of high-strength composite and stainless steel materials.
  • All operating parts are made of specially selected, corrosion- resistant materials.

Application Range

  • Available in male threaded sizes: 1/2”, 3/4”, 1”, 2” - NPT and 2” flanged
  • Maximum operating temperature: 140°F.
  • Maximum intermittent temperature: 194° F
  • For installation: Water transmission lines.

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Last Updated on: Sunday, 07 August 2022