Where do I install unions?

[JosephM]

I’m building a 29 gal reef tank with 20 gal sump. The sump is directly below under the stand. I’m using a fiji overflow box so I will have 2 pipes going down then making a 45° turn into stand and then another 45° turn down into the sump. I will be using a gate valve somewhere on one of the overflows, the one that’s not emergency. For the return I am using black vinyl tubing until it gets out of the sump and then using a fitting to bring it back to hard pvc (using sch 40 furniture grade black pvc) and then a 45° turn to the tank where it will go through the tank and into a nozzle for return. So my question is- Where would I need unions in this set up? I know it’s a dumb questions I’ve just never used unions before and don’t know where they’d best be placed. Thank you

 

[Brett S]

Unions would be used where you might want to remove plumbing in the future. So if you have hard pipe going from your bulkheads to fittings in your sump then you probably should put a union in there somewhere so you can pull out the sump later if you need to. You probably won’t need one on the return side since you are using vinyl tubing. That can be removed from a hose barb in the future if you want to do any work.

 

[MarshallB]

The 'best' place will be up to you. Unions are there to make your life easier if you were ever to take it apart for whatever reason. I like to put them before joints if I'm changing directions or angles.

I have a union right out of my overflow box, and another after entering the stand.

 

[KevPool]

use unions everywhere, if you see a spot that your unsure if you need a union add one anyways, if you see a spot that doesn't need a union add one anyways lol. no in all seriousness though if there is anything that you may need to clean in the future unions are your friend and makes any maintenance that you may want to do so much easier.

 

[JosephM]

Thank you all for the replies. I think I get the idea now of what I should work with. I really like your pictures @MarshallB might have to copy you lol

 

[AltitudeAquarium]

I agree with the replies above. Also, you will want an union just above the return pump even if you are using the black vinyl tubing. You will need to make it easy to remove the pump for cleaning, etc. I have unions for every elbow or transition in direction of the piping.

 

[Sebastiancrab]

I struggled with this too. See my build thread.