Chilled water reverse return line and balancing valve

Guest,

I dont understand "reverse vertical piping", a normal system would have a flow and return rising mains feeding submains at each floor. the submains would in turn feed each coil or subsubmains which would feed coils. Ballancing is not done in the mains piping at all, save a bypass valve if 3way coil control valves are not used. Each coil should have a flow and return isolating valve with an inline control valve in the flow line down stream from the iso valve or (depending on coil size) a 3way valve (opens to bypass coil) between flow and return lines.

in some cases the submains where they come off the risers may require a pressure initiated valve to ballance the submain itself. this may apply to subsubmains too

hope this helps

Phil

Yes,you are correct.We can use either of the two system i.e,if we are having reverse return piping then there is no need of having Automatic Balancing valves in each riser.However if there is no reverse return system then we need balancing valve in the direct return risers.