(1)Breathing valve should be installed at the highest point on the top of the tank. Theoretically, from the point of view of reducing evaporation losses and other exhaust considerations, the breathing valve should be installed at the highest point of the tank gas-phase space, in order to smoothly provide the most direct and maximum access to the breathing valve.
(2) when the tank volume is large, or when the tank is more important, in order to prevent a single breathing valve due to failure caused by the risk of overpressure or negative pressure in the tank, this time you can install two breathing valves. In order to avoid two sets of breathing valve action at the same time and increase the chances of failure, process design, usually the two sets of breathing valve suction and discharge pressure gradient design, under normal circumstances a work, the other standby.
(3) If the breathing volume is large, resulting in a single breathing valve can not meet the requirements of the breathing volume, you can set up more than two breathing valves. When installing two breathing valves, the center distance between them and the top of the tank should be equal, i.e., symmetrical arrangement on the top of the tank.
(4) If the breathing valve is installed on the nitrogen seal tank, the nitrogen supply pipe must be far away from the receiver position of the breathing valve interface, and inserted into the tank from the top of the tank about 200mm, so that the nitrogen into the tank is not directly discharged, to play the role of nitrogen sealing.
(5) If the breathing valve with a flame arrester, we must consider the pressure drop of the flame arrester on the pressure of the breathing valve discharge, so as to avoid overpressurization of the tank.
(6) When the average value of the temperature in the coldest month of the year in the area where the tank is built is less than or equal to 0, the breather valve must have anti-freezing measures to prevent the breather valve valve disk from freezing or blocking the tank exhaust gas or make-up gas is insufficient, resulting in overpressure tank drum or low-pressure tank.