Last summer, we received a phone call from a customer saying that the flange on the pump they had just purchased from us broke after being in service for only 20 days or so. It could be a quality issue, but those are rare. It was more likely there was something more at play.
One of our engineers went out to take a look at the system to see if he could troubleshoot the issue. It didn’t take long to see that this was a textbook example of pipe strain. There was a 15 foot, 2.5” diameter pipe coming down from the ceiling to a 90 degree elbow that then connected to a short length of pipe before connecting to the pump. No support. So not only was the pump supporting the weight of the pipe, it was also supporting the weight of the column of water it held. Pipe strain and flange breakage? Absolutely!
Pipe strain is a common problem just about anywhere that has pumps. If you’re looking to increase reliability in your facility, finding and fixing pipe strain issues is a great place to start.
WHAT IS PIPE STRAIN?
According to a recent Pumps and Systems article, pipe strain can be caused by “misalignment between the pump suction and discharge flanges and the corresponding pipe flange connections. Unacceptable pipe strain can be defined as any forces from unanchored piping that will cause equipment deformation of more than .002-in.”
WHAT CAUSES PIPE STRAIN?
There are 4 common reasons for pipe strain:
- Improper pipe support (or no support all together!)
- Process changes that did not account for the piping system
- Improper design or installation of pipe of machinery
- Movement in the system caused by temperature or pressure changes
PROBLEMS WITH PIPE STRAIN
Pipe strain is a big deal for pumps. It’s such a big deal, we’ve got it down as our #1 killer in our eBook 36 Ways To Kill Your Pump. Pipe strain causes misalignment, and misalignment brings on a myriad of issues, like increased vibration, premature seal and bearing failures, and increased power consumption. Pipe strain causes other issues like:
- Base plate damage
- Nozzle breakage
- Casing damage and distortion
- Premature impeller, stuffing box, casing wear, mechanical seal failure
- Excessive thrust or radial loading of bearings, seals, and other components
- Vibration of pipes that can transfer to other equipment
5 TIPS FOR AVOIDING PIPE STRAIN
So how can you avoid pipe strain and increase the life of your pumps? Use proper planning and installation techniques.
- Never EVER use a come along, chain hoist, or any other tool to force a pipe and pump flange to meet
- When installing pump piping, start at the pump, then work your way back
- Piping systems should be designed, not “field run”
- Support your pipes! Flanges on pumps are not designed to support excessive weight
- Utilize expansion and bellow joints to minimize effects of temperature and pressure changes
Pipe strain is a leading cause of premature pump failure, and should be the number one item to correct in your system. Doing so will allow you to get ahead of unplanned failures, downtime, and repetitive failures.
Need help to correct pipe strain and misalignment in your facility? Ask us about it! We gladly provide technical assistance to businesses and municipalities in Wisconsin and upper Michigan.