- every foot of pipe and every fitting creates a certain amount
of resistance and adds to the TDH. The higher the flow
through the pipe, the greater the resistance to flow.
- each valve increases the resistance, but not by much in most
Valves - these are one of the biggest contributors to
TDH. This is because the water takes a lot of right hand
turns inside the backwash valve and that creates turbulence,
which in turn creates resistance to flow.
- a filter (especially when it is dirty) can create a lot of
resistance to flow. Cartridge filters create the least
amount of TDH.
- the water has to go through a lot of tubes in the heat
exchanger and this creates resistance to flow.
Fittings - the size of the return orifice can have a
significant impact on the resistance to flow. Spa return
fittings are typically smaller and create resistance which