Tank blanketing is the injection of gas into a storage tanks vapor space. The purpose of the blanket is to maintain a layer of gas above the liquid to prevent the entrance of air into the tank. If air is introduced into the tank corrosion could occur, also the lack of positive displacement air could cause a tank to collapse.
The tank blanketing valve is used to maintain a minimum pressure in the vapor space of the tank. The valve has a set pressure to vent the excess gas into the vapor recovery system. A pressure change can occur during temperature changes, the pressure to increase or decrease.
Determine Blanketing Valve
- What is the gas capacity needed due to the maximum discharge of the pump.
- What is the gas capacity needed due to thermal effects of the tank wall.
- What is the total tank gas capacity.
- API Standards
- API Std 2000 - Standard for Venting Atmospheric and Low-pressure Storage Tanks - Nonrefrigerated and Refrigerated