Simple plumbing Q's

[heyfredyourhat]

Okay so before i go and buy a whole bunch of plumbing supplies, let me get a few things straight.
Gate valves, not ball valves....?? What about union ball valves ( what are they).
Try to have tees in drains for air escape, try to have drain enter at a 90....i think i read that somewhere but i am not sure why..??
Use standpipes, try to get as much linear skim action in tank as possible....
For a closed loop is it essential to have gate valves or can i use ball valves, or union ball valves (if i think thats what they do)....
I thought there were more, but i am drawing a blank.
Anything i forgot please reply.

 

[Holyreefer]

With plumbing the best thing i found is to draw it out and then dry plumb it then see if its what you want and make it happen.

This is a union value
http://www.usplastic.com/catalog/pr...ory_name=15655&product_id=25185&cookie_test=1
You usually see people but them on places where they can detach a piece and the plumbing and reattach it again ie like on a pump for cleaning, repair or replacing...

 

[heyfredyourhat]

so unions are basically a coupler with a shut off valve then. Hmmm, seems quite handy.

 

[Holyreefer]

Correct