i'm sure you are well aware of the multiple types of plastic and pvc fittings that have male threads. why assume? not that it makes alot of difference, i was jw. maybe its not a male adapter with a lip, maybe its a sch. 80 nipple and someone overtightened it into the pump? .. just asking questions, cool ur jets.
"Screwing into" says male threads. It doesn't matter if it is a nipple or male fitting, it is overheated and blowing out of two different pumps; one is cast iron. Replacing a PVC fitting with a metal one as you suggested or went along with doesn't cure the problem, it treats the symptom.
"The threaded part is "out of shape" so to speak like if it was heated".. i dont know whether op means the fitting, or the pump's discharge threads, or both.. so how could you?
The PVC fitting is the logical choice AND he says he replaced the fitting and it deformed and blew out again; on both pumps.
The keyword is deformed. The plastic used for the pump body can withstand higher temps than PVC can. They are two very different types of plastic.
there is that possibility.. i previously asked what the cutin/cutout pressure was. op said pump was shutting off. could be set to high? power problem? could be something else. what is your professional opinion with the information provided so far?
Until the cause of the pumps overheating is found and fixed, there is no sense in looking at the possibility of other causes of his deformed fittings problem.
BTW.. i dont NEED to do anything. my water system works excellent. i'm just trying to help out someone whose having a pump problem by asking questions in hopes to get closer to a solution, as its a topic i'm somewhat familiar with. what are you doing?
To help out someone you need to be a better troubleshooter or your wasting his time and yours.
If he doesn't find and fix the cause of the pumps overheating, I'm sure he will have a pump problem soon, and still have the cause of the overheating a new a pump.
I suspect he is pumping the well down too far by the time he has watered 4-5 zones and/or the cycling the pumps on/off or no water is overheating the water and that then overheats and deforms the PVC fitting until it blows out of the pumps.
Or he could pull the water level in the well down to a point where he has a suction leak allowing air to cause a loss of prime. Or he has a leaking foot valve or not as much water in the well as he used to have.