Hi all,
The pump is below the pool level, and one of the valves was not closing correctly.
The pool guy came and replaced the 2" pipes with 1 1/2" pipes
Before (on the left) vs after (on the right) :


At the bottom left the incoming pipes are Skimmers / Vacuum / Bottom drain
and the pipe on the right goes to the pump
After this "repair", I felt that vacuuming was less powerful, so I called the pool guy and told him that I thought that the new pipes 1 1/2" were the problem (instead of the old 2" pipes)
He told me that is was not possible as the vacuum pipe before the valve is 1 1/2", the valves were 1 1/2" so it was no use putting 2" pipes after
I've found this table : https://media.wattswater.com/Orion-HP-FrictionLoss.pdf

so I think replacing the two 90° long radius elbows (2") with two 90° street elbows (1 1/2") also has an impact
What do you think?
The pump is below the pool level, and one of the valves was not closing correctly.
The pool guy came and replaced the 2" pipes with 1 1/2" pipes
Before (on the left) vs after (on the right) :


At the bottom left the incoming pipes are Skimmers / Vacuum / Bottom drain
and the pipe on the right goes to the pump
After this "repair", I felt that vacuuming was less powerful, so I called the pool guy and told him that I thought that the new pipes 1 1/2" were the problem (instead of the old 2" pipes)
He told me that is was not possible as the vacuum pipe before the valve is 1 1/2", the valves were 1 1/2" so it was no use putting 2" pipes after
I've found this table : https://media.wattswater.com/Orion-HP-FrictionLoss.pdf

so I think replacing the two 90° long radius elbows (2") with two 90° street elbows (1 1/2") also has an impact
What do you think?