After many years and lots of “fixing” of pipes, valves, etc. in my utility closet, a plumber finally said that he thought the ongoing problems were being caused by the dryer vent…the way it squeezes thru the tight area of pipes and outside…it rest directly on a pvc pipe. Whenever I run the dryer, condensation forms and drips down the wall. Also, the joint leading to the main water shut off valve has failed twice…theory…the adhesive keeps getting heated by dryer vent and then cooling, etc. WHAT CAN I DO??? The plumber didn’t have any suggestions and I’d like to try something besides trying to find someone to re-route the dryer vent. How about insulating the pipe somehow??? Help!
Is the pvc pipe water are waste. If it is water then the heated pipe will cause pvc to sweat. Get some pipe insulation and put some around pvc and dryer pipe, make sure the dryer insulationis fire proof. Where ever it is touching another pipe put insulation around it. If you can hang dryer pipe so it is not touching other pipe might help.
Here’s my WAG from the other side of the internet. (it’s kinds hard to see your plumbing from here) Perhaps the dryer vent is warming up the air around the pipes. Warm, moist air will condense on cold water pipes. I doubt it has anything to do with direct contact. Insulating the pipes should help. Also, if the dryer vent is leaking it will be leaking very warm moist air.
As far as your leak at the shut off valve, I am not fond of the theory. The ‘adhesive’ (whether it is pipe dope or solvent cement) should not be affected by warmth. On the other hand, PVC is not designed for hot water and it gets soft when heated. If it is getting really warm and it is a threaded PVC connection, the threaded PVC could be getting soft and causing the leak.