Low pressure line bursting

[washman2016]

I can not figure out why i keep blowing my low pressure lines. I put in all new lines. I put hangers in to keep them away from the high pressure lines. I replace the check valve every time i fix a line. I am running 80psi the tubing is rated for 120. It is random between my 5 bays but tire cleaner goes more then presoak. I will blow a line every 3 to 4 weeks.

 

[traveler17]

Sounds like a bad check valve imo. Does it blow it out when you switch from low pressure to high pressure. I had same happen and it was busting flojets , low pressure lines when I switched to hp. I put in 16 new check valves and still had the issue. Turned out bad run of valves from the manufacturer.

 

[Rudy]

Bad Check Valve somewhere...

 

[washman2016]

So I THINK I have figured it out. I am using a MX8 controller to turn on my Electric pump. I found out that the MX8 has a 1 sec delay turning on and off. So I am guessing the delay off is cousing the surge blowing the lines. Question is how do I fix this?

 

[Randy]

Replace your tubing with Black Nylon DOT tubing, it has a burst pressure of around 425-450psi. It'll probably be the last time you'll have to mess with it.

 

[Greg Pack]

If it's a new line and an overpressure issue the damage caused likely will "balloon out". If it is UV damage to the poly lines it will crack. Also, heat lowers the working pressure of lines but it should still have a burst pressure much higher than working pressure.

I thought the MX had a delay on, but not a delay off. But looking at Kleen rite's catalog it says it also has a delay off. Regardless, a check valve should close before it builds up enough pressure to rupture a line in front of it. You could try a simple delay on timer on your HP pump if you truly think that is the issue. They are pretty inexpensive, $20 each or so.

Here's one:https://www.supplyhouse.com/ICM-Con...ake-Timer-1-1023-Second-Switch-Settable-Delay

 

[Randy]

I run a Procon pump set at 125psi controlled by a IDX MX-8 multiplexer. The MX-8 has a 2 second On and Off. delay. I've never had a problem with tubing bursting. Some the Polyethylene tubing sold online isn't the best for use at the car wash.