SINGLE DIAPHRAGM PRESSURE TANK - PTB 235

Diaphragm tanks are commonly 
used on the discharge manifold to 
provide water storage for the system
 in very low flow situations.
 It decreases the running time of the booster pumps,
 thereby making the system more energy effective.

Diaphragm pressure tanks are the most efficient
 type of pressure tank and require the
 least amount of maintenance due 
to the use of a rubber lining inside 
that separates the air and the water. 

This rubber lining acts as the bladder
 would, but its connection is permanent
 to the tank. Therefore, it is not replaceable.
If this happens, there is little air 

left in the tank to become compressed, 
so the pump runs nearly 
every time water is used. 
In addition, too much air in the tank is a problem 
because it reduces the space for water storage.
 Extra air must be released or the tank will become air-bound.