why is the skimmer line size larger than the other lines?

On my old (30+ year) in ground concrete pool the skimmer line size is 2" from the skimmer through the pool shed through a 2" gate valve and 2" all the way to the pump. All other lines, pool return, drain, spa drain, spa return and even the pump to the filter are all 1 1/2". I want to update all the plumbing in the shed and get ride of all the gate valves. (Kinda looks like the WW I submarine now.)
It would be easier to re-plumb it all in 1 1/2". But, is there a reason for the skimmer line being larger? The only possible reason I could think of was to help make it more clog free.


Cheers, and thanks in advance.

Probably, you can step down to 1.5". (Why does Canada use a mix of SI and US measurements?)

But I can't give you a definitive answers without pump / filter / pool size information.

. . . membership updated.

Yeah things are mixed up here. Wine is sold in liters and beer in pints. go figure.
pool ~ 20 X 40 foot concrete pool (pools are also in feet)
filter taglus (sp) sand filter
pump dual speed (I upgraded the motor) 1 HP and I guess about 1/6 hp.
My overall goal is to:
1) replace the valve on top of the filter (It got warped from an over heating indecent when I was out of town awhile back)
2) get rid of all the globe valves ~ 8 of them including 3 for the heater bypass
3) get rid of the 30 year old tubing and uncountable band clamps, tubing mismatches, etc.
4) make the whole thing simpler and more fool proof by using modern 3 way plastic valves

All-in-all I could simply finish of the skimmer line to the pump with 2" pipe for very little money.
Indeed the three way valves connect to 2" elbows directly as I understand.

One other question to through out is This is all to be on a wooden wall in a pool shed. Any suggestions on how to mount the pipe to the wall?

Cheers, and thanks.

There are lots of ways to mount piping, but I used a LOT of Clic hangers over the years. They make a very neat and serviceable installation.

I'm not sure what's happened; the original company (Litchfield International) now sells "HangerLok" hangers that are the same thing. Spears (PVC mfg) seems to be selling the original hangers, but you'd have to order through a plumbing or piping supply outfit. I bought them from an industrial PVC wholesaler in Atlanta.

http://www.aetnaplastics.com/site_me...t_Brochure.pdf
http://parts.spearsmfg.com/ProductDetails.aspx?pid=285

Amazon is selling a functional copy of the Clic hangers:

Plastic snap hanger for pipe and conduit