P/V Vent with In-Line Vault

Defender Series® Pressure/Vacuum (P/V) vents regulate the pressure at which vapor is allowed to escape from the underground storage tank and the vacuum at which outside air is allowed to enter the tank. The P/V vent’s internal rolling diaphragm delivers consistent and controlled cracking for both low leak and high-pressure conditions while the superior construction of UV-resistant materials extends the overall service life. The in-line vault provides added protection and facilitates at-grade servicing and testing. This eliminates the added expense of lift trucks as well as the potential safety concerns of conducting work at height.

Order Info
  • Highlights


    Pressure / Vacuum Vent

    • The P/V vent is constructed of high-grade, UV-resistant materials and premium internal components designed and tested to last.
    • A rain cap with stainless steel mesh debris shield protects the system from water and insect intrusion.
    • The one-turn locking mechanism provides easy installation and removal for servicing.
    • High tolerance for over-pressure situations.
    • Compatible with all fuel types.
    • A rolling diaphragm achieves low leak rates and high flow rates with a tight and consistent seal.
    • Includes 2" NPT vent stack adapter.
    • The internal female threads are compatible with OPW® vent stack adapters for easy retrofit onto existing sites.
    • Compatible with manifolded vent applications.


    In-Line Vault

    • The cast ductile iron enclosure houses the P/V vent for added security and protection from the environment while also placing it at grade-level for safer, cost-effective maintenance and testing.
    • The vault includes a UV-resistant rain cap with a stainless steel mesh debris shield for the top of the vent stack.
    • The stainless steel gasketed faceplate includes a swivel pin that holds it in place during service.
    • Tamper-resistant screws secure the faceplate to the vault.
    • Eliminates wrenching at height.
    • Integrated drain plug facilitates draining of condensate.

  • Specs

    • Pressure setting: 2.5" to 6.0" WC
    • Vacuum setting: -6.0" to -10.0" WC
    • Pressure leak rate: ≤ .05 CFH at +2" WC
    • Vacuum leak rate: ≤ .21 CFH at -4" WC
    • Maximum flow rate: 8,000 SCFH at 2 PSI
    • Operating temperature: -22° to 122° F (-30° to 50° C)


    • P/V vent body: UV-resistant polymer
    • Seals: UL Listed elastomers
    • Screens: Stainless steel
    • Rain cap: UV-resistant polymer
    • In-line vault body: E-coated cast ductile iron
    • In-line vault cover: Stainless steel

    Approvals & Certifications

    • UL2583 listed.
    • Meets the requirements of EPA 40 CFR part 63 for Gasoline Dispensing Facilities


    • 1. P/V vent
    • 2. Rain cap
    • 3. In-line vault
    • 4. In-line vault faceplate
    • 5. Defender Series® vent stack adapter
    • 6. OPW® vent stack adapter (not available for purchase)


  • Order Info

    In-Line Tank Venting

    Install in-line at grade with the in-line vault and rain cap.

    DPVV(1) Defender Series® P/V vent with (1) In-line vault and (1) rain cap

    End-of-Line Tank Venting

    Install end-of-line with the Defender Series® vent stack adapter

    804100901Defender Series® P/V vent, and Defender Series®  2"  vent stack adapter

    Retrofit & Replacement Parts

    Order a P/V vent compatible with OPW® P/V vent adapters to retrofit existing OPW® vent stack adapters.

    804100930Defender Series® P/V vent (includes O-rings for both Defender Series® and OPW® vent stack adapters)
    804023901Vent cap
    804110901Maintenance kit includes inlet screen (includes O-rings for both Defender Series® and OPW® vent stack adapters)
    804110902Vault faceplate gasket
    804110903(2) replacement tamper-resistant screws for vault faceplate
    804110904Vault service plug, prevents vapors from escaping during maintenance
    804110905Vault L-key wrench (T40 tip size)
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