A house without leaky pipes need not be a distant dream

How variable speed drives can help reduce the pressure shocks in pipelines

Our bathroom water pipes had a leak, but that doesn’t usually motivate me to write a column. So what is the reason you may wonder? Well, first, my bathroom leak did not really surprise me as the house we are staying in Dubai is 12 years old and requires continuous maintenance to keep it up and steady!

But constant leaks began to intrigue me and I chatted about it with the plumber. He had the choicest words of abuse for the builder who he said had used cheap piping material that was causing the leak. The water pipes were made of plastic instead of copper.

All the hassle around drying the water and fixing pipes made me think of how to avoid it. Changing all pipes in the house would be expensive and difficult, so it would need to be something else.

The plumber said that plastic pipes were vulnerable to water temperature and pressure changes. I cannot do much about the temperature because we need both hot and cold water. But what about pressure changes?

In Dubai, general pipeline pressure is quite low and most houses have booster pumps to increase it as required. I knew our house also had them but hadn’t paid much attention to them before this.

Now suddenly, I was keen to see what kind of pumps were installed. And guess what – we have two pumps for redundancy but with direct online starting. This means that every time someone opens a tap, one of the pumps start and cause a sudden pressure shock wave in the house pipeline.

Now it is very obvious to me why we have water leaks in a house that has plastic pipes. It’s actually a little painful for me to think about this, as I have been dealing with variable speed drives (VSD) practically all my career in one way or another. And in addition to energy saving, one of the key features of VSD is to achieve smooth starting and avoid shock waves in the pipeline. Just by installing a VSD to the booster pumps, the risk of leaks could be reduced considerably.

The very same evening after our house was flooded and I was stuck with a leaky bathroom and an irate plumber, I saw a burst irrigation pipeline creating a huge water pond on the road. Obviously the pipe was also made of plastic. I think you can guess what I am thinking: we can do a lot more to preserve scarce water resources with relatively low but smart investments.

To put the matter in perspective, I searched the internet briefly. Some interesting data is available for e.g. from the U.S. Environmental Protection Agency, EPA. According to them, the US National Studies indicate that on an average, 14 percent of the water treated by water systems is lost to leaks. Some water systems have reported water losses exceeding 60 percent. Accounting for water and minimizing water loss are critical functions for any water utility that wants to be sustainable. This clearly indicates that we are dealing with a globally significant issue that require immediate attention. If you are interested further, please have a look at water.epa.gov.

Actually, I have already understood that many utilities in the Middle East see the importance of water leakage detection and elimination. This is obviously critical in region where most of the sweet water is produced in desalination plants as reducing water consumption also means less consumed energy and less carbon di-oxide emissions. Upgrading irrigation pumps to VSD control can be an effective addition to the toolbox to cope with the challenge.