headloss in bypass control valve in hvac

It depends upon a lot of things. Here are some of them:

• The elevation of the cooling tower spray nozzles above the pond
• The size and length of the cooling water system
• The amount of tolerable build-up of solids on the insides of the pipes
• The flowrate in the pipes
• The temperature of the cooling water
• Etc.

none of which can be seen from here.

thanks Mr. PWSlack its mean i have to do some calculation for friction, static and residual head in future i will be in contact with u

Post the data in this thread so that others may help too.

_{<...Mr...> How abstruse!}

The ans. all depends on the variables you can supply us with. My suggestion in the valve department for maximum flow: use a single throw "ball "valve that is one pipe size larger than the pipe that flows into and out from it. This gives you less resistance than a "gate" valve which provides the most restriction to the flow of water. Brass or PVC have economic and replacement value considerations to consider. Hope this is a help. If you can give me pipe size's and length of runs between tower and chiller and the height of each unit I can supply further information for you.