Dec 15

Understanding Fluid Bypass

A fluid bypass is found on many chillers, but what is a fluid bypass and how does it benefit a chiller?

The fluid bypass valve, sometimes referred to as the pressure adjustment does just that; it gives some pressure adjustment.  A fluid bypass protects the pump from “dead head” situations.  “Dead heading” occurs when the pump is running and the flow loop outside of the chiller is blocked.  A blocked flow loop can cause an instant rise in pressure to the pumps maximum output pressure.  The instant high amperage spike can damage the pump by blowing a fuse or circuit breaker.

Other system components in the chiller or in the process  are subject to high pressure damage as well.   An internal spring setting opens where there is a rise in pressure and thereby protects the pump and other components  The opening instantly releases the extra pump pressure by allowing the pressure to flow through the bypass and back to the heat exchanger and then returns to the tank.

Some people expect that the bypass can be set to any pressure they want and reduce their flow too much.   However, what is forgotten is that pressure and flow are linearly related;  when pressure drops so does flow.

This makes it essential to select the right flow rate, plumbing size and understand the pressure drop through the process being cooled.

If you have questions about a fluid bypass,  a member of our sales team will be happy to you.

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