I have a hot water tank with 25mm / 1" connections and have to use a circulation pump and pipe that is 20mm, then connecting to another tank that is 20mm ports. In order to keep good flow from the 25mm tank do I simply upsize my pump to get the more water moved, or is that like trying to cook something in the oven twice as high heat for half the time?!
Or asking another way, is twice the water speed in small pipe = half the speed in large pipe?
Morbo
Member
darrynm said:
Or asking another way, is twice the water speed in small pipe = half the speed in large pipe?
how long is a piece of pipe?
Simple. Formula for volume is known? Then obviously velocity in pipe is volume flow divided by pipe cross section. Pipe cross-section is related to the square of pipe dia. Its a worry we have to do grade 5 maths here.
Friction loss is then square to velocity in pipe. So double pipe dia. 1/4 velocity and 1/16th losses. 25 dia to 20 dia pipe 1.5 fold velocity, 2.4 fold losses.
Friction in poly pipe is very small, but fittings may cause problems. Especially orifices
