gluing PVC into running setup
 

I need to add a T fitting into my return to feed a frag tank. How long before I can safely start the return up again ? I know the joint itself is fine after prob 15 seconds but I'm concerned about the safety of my inhabitants.

Using standard primer and glue thx.

I just extended my emergency overflow piping to the sump and used
Carlon all weather quick set clear PVC glue, that requires no primer, and had no problems. It's the primer not the glue that I would concerned with. This glue is made for the grey electrical PVC which is the same as the white stuff except the grey pipe and fittings are uv resistant I'm told. Bought it at Home depot. :smile:

I've done the same thing, left it a couple minutes and started the water back up. No issues.

Plus 1here

All I have here is the primer and glue. Did any of you use that or everyone had the primer free method? I don't mind making a trip to get some. Thx!

Honestly, I've never used primer in PVC.

Ya I never have either, but when I was talking to an electrician friend of mine who works at Home Depot he told me about this glue I use now. I would just use what you have without the primer, I've done it lots of times, should be fine, up to you. :neutral:

For things dealing with higher pressure, I personally would recommend primer.

Higher pressure in our setups would be a closed loop (weight of the water of the entire tank pushing on the loop plumbing). A return is *high* pressure, but if it's not restricted (smaller output than the pump's output) it's not really that high of a pressure.

When it comes to Flex, I use Rain-R-Shine, and only use primer on the hard pvc fittings - the Flex just gets the glue (flex needs to be wiped clean with a clean rag first though)


....I just re-plumped the return to my closed loop this morning in fact, and waited a cool 10 minutes until the valves were opened again and the pressure applied to the new joints, no issues :)

During the extrusion process, a waxy layer is brought to the surface of the tube. The primer, dissolves this wax, so when I apply the glue, it is bonding the plastics together. On a non pressure application this step is not a big deal and is often skipped. On larger, high pressure application, the use of a primer is a must.
Although I wouldnt consider our tank a high pressure situation, we do have to take into acount head pressure that may be above the joint.
Just my 2 cents, been working around this stuff for the last 20 years or so...