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Anderson Greenwood Type 4020 Atmospheric Pressure and Vacuum Valves
Marvac Type 4020 Atmospheric Pressure and Vacuum Valves
Weight or spring loaded valves capable of providing pressure and vacuum relief that vent to atmosphere.
Designed and tested to reduce costs and emissions with higher flow capacities and industry leading conformity to API 2000


  • Increased flow capacities reduce the required valve size and the corresponding connections and piping costs.
  • Fully open at 10% overpressure, enabling setting close to MAWP/MAWV and minimizing tank emissions.
  • Large body for increased capacity providing high flow performance for full conformance to API2000/ISO28300.
  • Leakage rate of 0.5 scfh (0.015 Nm3 /hr) or less at 90% of setpoint.
  • Weight or spring loaded models available.
  • Choice of body materials.
  • Modular design enables all components to be removed and replaced in-situ for quicker, simpler maintenance.
  • Optional ‘all-weather’ coating prevents frozen condensate build-up and sticking of vital components in cold weather applications.