View Full Version : Expansion tank in closed loop systems

25-03-2014, 10:16 AM
Would someone be able to assist with set up information of closed loop system
What is ideal pressure in bladder.


25-03-2014, 01:54 PM
How tall is the building and is the vessel at the top or bottom of it?

25-03-2014, 08:04 PM
It's not a building but a new processing plant.
It has one closed loop with tank on top of evaporative air cooler for screw compressor oil cooling.
Water circulates through tubes in evaporative cooler, so has an expansion tank above it.
Also a closed loop glycol system for process cooling. Expansion tank mounted on pump return line.

Tanks supplied with 200kpa pressure, interested in how to determine pressure in expansion tank ie when system is off do you have it same pressure of what's in system or is it something to do with pump suction pressure while running or do we do nothing.
Assume systems are fully primed & operational.

install monkey
25-03-2014, 08:12 PM
you need to know the volume of the system to calc the vessel size and charge-

install monkey
25-03-2014, 08:14 PM

25-03-2014, 08:28 PM
The bladder in the expansion vessel has to be at a greater pressure than your system so that it can absorb the circuit hydraulic expansion.
What you need to do is calculate the maximum hydraulic expansion ( increase in pressure)
If the circuit can't expand your pressure relief valve will pass.