pvc help

[philburt]

this might be a strange question I was planning on making a closed loop and was planning on using half in pvc ,on the out side of the tubbing it states that high temp 75. of course temp is not to high over that, but sales man at the store stated if temps exceed that they can stretch and pop fittings off(over time im guessing) . i am a paranoid person and that does not help in this hobby . so is there any advice on this or any problems anyone has had thanks

[Mr. Tang]

do you have more info on the tubing???
I have never heard of any type of pipes that would be questionable at such low temps.I know flexiable tubing can be heated to make it easier to fit over fittings.

[philburt]

here is what is printed on pipe < PVC 13.5 315 psi pr water at 73f deg f pvc 1120>

[lReef lKeeper]

sounds like schedule 20 PVC ... is it a thick wall or thin wall tubing ?? i would go to Lowes or HD and get some schedule 40 PVC, i use this on all of my plumbing and have never had a problem with it.

[philburt]

it is the thinner of the two thank you

[Mr. Tang]

I have been using pvc pipes in my landscape business for over 15 years. I have also used schedule 200 3/4" and 1" and 1 1/2" pipe. in my aquariums. I have never had any problems with this pipe from streching or melting to the point where the fitting didn't hold water. I live in the southeast and we get hot in the summer!!!! I even have had pvc pipe exposed to the sun without any ill effects.
Now the only differnece between these pipes is the inside diameter. Same material, just a little thinner on the inside. Also, the lower the number on the pipe, the thicker the pipe is. The problem with going with the thicker pipe is that the inside diameter is smaller thus less flow. I personally wouldn't use the schedule 40 because of a couple of reasons. First it does have some effect on the flow of water thru the pipe. Second, the fitting are more expensive. If you look at my newest system, I have saved a lot of money using schedule 200 fittings and pipe. Thirdly, schedule 40 pipe is harder to cut than schedule 200. If your'e using pipe knives, it takes more effort to cut. If you use a saw than you have to worry about shavens in the system.

No matter which pipe you use, you WILL NOT have any issues with the pipes not holding up!!!

Hope this helps

Mr. Tang

[Amphibious]

Originally Posted by philburt

here is what is printed on pipe < PVC 13.5 315 psi Page Ranking water at 73f deg f pvc 1120>

The key to the numbers is this...
The pipe will withstand up 315 psi at 73*F. Your closed loop will have near zero psi because it has open ends. If you had a very sensitive guage you might be able to read the pressure differential on either side of the pump since the pump creates a pressure difference to move the water.

Does that make sense?

[lgarver]

You should be fine, 315 psi is alot, even at 78-82 degrees, a closed loop should not produce that amount of pressure.....