Hi. I installed a 250m if 19mm poly to transfer water however the sun has flattened the pipe due to heat build up. This is not green or blue line pipe but the cheapest from Bunnings. Is this faulty pipe or incorrect application? If the latter is true, which one should I use? I don’t have the opportunity to bury the pipe due to hilly and rocky terrain
Welcome to the Bunnings Workshop community @Tonycoops. It's great to have you join us and many thanks for your questions.
Was this the Holman 19mm x 100m Black Poly Pipe? I've reached out to Holman to ask if they have had any feedback similar to what you have experienced. Unfortunately, this is not something they have heard of before. They did mention that the pipe is used all around Australia in some fairly extreme environments without such issues. They are eager to assist and find out what has caused this problem. Were you able to post some images of the pipe and the flattening which has occurred? Alternatively, Holman is happy for you to contact them directly at their Contact Us page.
We look forward to assisting with the issue and finding a solution to your problem.
The polypipe you are using only has a thin wall and becomes soft in the sun. It is designed for irrigation and being under low positive pressure. I would suggest if the water is going down a considerable hieght you may have a case of syphon vacuum collapse. Basically the water in the pipe for that size and length would have a mass of 70kg. When you shut the tap at the top the weight of the water below the tap can cause a vacuum collapsing the pipe. I have heard of this before but never had to deal with it personally. A tap at the end may help but probably a case of using pipe with a thicker wall. Also at 250m increasing the diameter of your pipe to 25mm should double your flow JDE
Thanks for that. I installed the 19mm to prove I could lift the water 18m over 80m. Once over it falls to a tank and has not tap installed. I agree that pipe is too thin walled for the sun so was thinking 1 or 1 1/4 inch.