Type 4020 Atmospheric Pressure & Vacuum Valves

High Capacity VentsAnderson Greenwood

Weight or spring loaded valves capable of providing pressure and vacuum relief that vent to atmosphere. Designed to work closer to a tank’s MAWP, increasing productivity, reducing emissions and product evaporation

Type 4020 valves allow tanks to work closer to their MAWP thus increasing productivity, reducing emissions and product evaporation. Increased flow capacities reduce the valve’s size, corresponding connections and piping costs in applications for storage tank farms, oil and gas production, the petroleum, pharmaceutical and chemical sectors.

  • 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.

Technical Data


Conservation Vents


Up to 1.45 psig




NPS 2-12


Aluminum, carbon steel, stainless steel



Document Type

View Results