Relief valves have their main applications in tanks with fixed roof for the oil and petrochemical industries. According to the “Flammable Liquids Regulations”, NN 54/99, oil tanks must have closed type normal and a safety valve.
The role of the relief valve at the reservoir openings is as follows:
- Prevention of pressure increase in the reservoir due to the filling of reservoir with medium or increase of ambient temperature
- Prevention of vacuum in the tank due to emptying of the tank or dropping of ambient temperature
- Preventing the penetration of various impurities in the fuel tank.
Relief valve works on the principle of raising the pallet (pallet consists of the cover, guide bar and the gasket) due to the pressure difference between the tank and the environment. Opening the valve at different pressure (and vacuum) is achieved by placing additional weight on the pallet.
RELIEF VALVE type DVER (pressure – vacuum)
Relief valve is designed to allow long lasting and safe operation under all conditions with minimum maintenance. The valve body is made of cast aluminum with bars and palettes of stainless steel. Gasket is made of rubber resistant to the impact of the media in the tank. Relief valve is set at 0.22 kPa of pressure and 0.22 kPa vacuum or per request.