Diaphragm pump
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This post was last edited by wx_Leary JIANG2 on 2020-3-27 at 10:50. Hello, dear friends. I have a question: when a pneumatic diaphragm pump is connected to other equipment, if the fluid storage tank of that equipment is located much higher than the installation location of the pump, it is important to install a valve that can be completely closed on the outlet pipeline. The outlet valve should be fully closed when the pump is stopped, in order to avoid any damage to the pump that might result from back pressure at the outlet. Because the back pressure in the outlet pipeline after shutdown causes the diaphragm to remain under stress and compression for an extended period, which reduces its lifespan. It is even possible that, when the machine is shut down, the diaphragm may be damaged due to back pressure, resulting in liquid leaking from the valve assembly. If the outlet backpressure exceeds 0.3 bar, a valve must be installed at the outlet. The most ideal solution is to install a shut-off valve on the inlet pipeline to reduce the damage caused by back pressure to the diaphragm. Why is a shut-off valve installed on the inlet pipe instead of raising the outlet back pressure above 0.3 bar?
A shut-off valve is installed on the inlet pipe to reduce the damage caused by back pressure to the diaphragm. Is this sentence correct?
Diaphragm pumps are equipped with check valves at their outlet – so how can pressure be applied back to the diaphragm? Additionally, diaphragm pumps are positive displacement pumps, and it is not recommended to install valves at their outlet; if such valves are installed, they need to remain open at all times. I don’t understand this – 0.3 bar of pressure isn’t that high