What are Safe PVC Temperatures?

[TheTrooper]

Hey, since winter is already here and its getting colder and colder each day, I just want to know the safe operating temperatures of PVC (hot and cold). I'm too lazy to search (yes i did use search button though).

[the beast]

Id probably say between 50-95 but when it starts getting towards 50 just dont go to full psi.Anywhere above or below just dont use it for prolonged periods outside.

[Hailfire753]

Hmm... this is weird. I just looked it up, and supposidly PVC can hold more PSI as temperature decreases. People always say that hot or cold weakens the pipe, so I do not know how true this is. Here is the clip:


How does temperature affect the pressure rating of PVC pipe?
PVC pipe is pressure rated at 73° F (23° C). As the temperature drops below 73° F the pressure capacity increases and is usually considered an additional safety factor and not taken into account. However, as the temperature increases above 73° F, the pressure capacity of PVC pipe decreases and the pressure capacity must be de-rated.
Following is a pressure de-rating chart for PVC pipe. To calculate the new pressure rating, multiply the working temperature by the de-rating factor. For example, pipe rated at 150 psi at 110° F would have a new pressure capacity of 75 psi (150 x 0.50 = 75).
Maximum Service Temperature De-rating Factor
73° F (23° C) 1.00
80° F (27° C) 0.88
90° F (32° C) 0.75
100° F (38° C) 0.62
110° F (43° C) 0.50
120° F (49° C) 0.40
130° F (54° C) 0.30
140° F (60° C) 0.22

Source: UniBell HandBook of PVC Pipe 4th edition 2001, pg 123

EDIT: I get it now. PVC can hold higher PSI as temperature decreases, but it also becomes more brittle. This means that it it fractures easier if it is droped or hit. If you can shield it from too much jostling, it sould be OK.

Combustions are fine to use in the winter, but using pneumatics is more dangerous.

[TheTrooper]

Oh thank Hailfire, lol that article contradicts everything people have said good job

[Hailfire753]

No problem. Just don't get hurt!

If you plan to use your gun in winter, I would test it remotly first if possible.

[BC Pneumatics]

If you get a chart that goes well below 73*F, I believe it will start to drop again as well.

[sandman]

yes your chart goes to room temp, after that it should drop again

[Hailfire753]

Yeah, that's what I thought as well. I assume the brittality will cause the pressure rating to lower after a certain point.

How do you think CO2 will affect the temp of PVC, and its PSI rating?

[boilingleadbath]

Eh, strength of thermoplastics increases with decreasing temperature. Period.

Besides just looking at graphs of the quality:

http://www.pipa.com.au/docs/PV008.html

and <a href="https://www.ppfahome.org/pvc/faqpvc.html">this</a> table:
I also found a table in which:
70*F = 1.04
60*F = 1.15

[BC Pneumatics]

BLB, you are being a bit vague, and misleading. While the tensile strength of thermoplastics does increase with a drop in temperature, the impact strength decreases.

[Novacastrian]

I also found a table in which:
70*F = 1.04
60*F = 1.15[/quote]

Can you provide the table?

[Eddbot]

i think i had an idea supporting hailfire's research, just don't flame me if i'm wrong
PVC is not known for it's malleability soo when it gets brittle it can take more pressure before it reaches it's breaking point than at higher temps

[clide]

Yes. PVC's strength does increase as the temperature decreases. However the brittleness is a serious factor because of the high impulse loads that a gun will experience. Personally I don't use it below 50 degrees.

[TheTrooper]

I agree because under 50 degrees it would be much more brittle than slightly warmer temps, luckily where i live it doesnt get that cold Usually

[spudgunnerwryyyyy]

Yeah under 50 would be way too dangerous. But another factor almost more important is if the pvc was left out in the sun as vinyl breaks down quickly in uv light.