New plumbing question

[vinnie]

So i'm about to cut everything out and completely redo my plumbing and all my equipment. Right now everything is hard plumbed. Should I be putting unions between everything so I can replace each item piece by piece if I need to?

Plumbing in

Filter
Pump
3 valves
autopilot
heater

Thanks,

Vince

[JasonLion]

You don't want to put in unions for every piece of equipment. That creates too many possible failure points. In many cases, a few well chosen unions can be handy, but you don't even need that if you leave appropriate spots where the pipe can be cut should there be an issue.

[vinnie]

are there any places in particular you think I should put them?

Also is there a link you can point me to or any pointers you can give on anything else I should be doing or looking out for when re-plumbing? I think I read somewhere about a length of pipe going into the pump needing to be at least a certain length? wasn't sure if there were any other "rules" like that i need to look out for. I know from a previous post that I don't need any check valves.


thanks for your help

[JasonLion]

We don't have a PVC plumbing article in Pool School yet, maybe someday.

Yes, the pump likes to have about one foot of straight pipe leading into the inlet.

A few key issue with PVC plumbing include: Lay things out in advance as cleanly as possible so you can minimize the number of bends/fittings that you need. Figure out what order to do things in so that each connection has enough room or give in it so that you can actually get the pipe into the fitting. There is nothing worse than getting to the final joint only to discover that you can't pull it far enough apart to get the pipe into the fitting. And of course, measure twice, or three times, and cut once. Keep in mind that the pipe will fit more deeply into a fitting when it has glue on it than it does when you are dry fitting. Along the same lines, the glue can make the pipe try to jump out of the fitting, so hold tight for several seconds till the joint freezes up.