Why is water used to test a pipeline or system...instead or compressed air?

Answer 1

Because you can see water !

Answer 2

Since most of the pipe in a pipeline system has an external coating system, it is very difficult to detect leaks using air. Even if you know there is a leak, trying to find an air leak can be quite a problem. You usually need something like a soap system to look for bubbles or a sonic system to listen for the leak rather than just looking for wet spots.

In pipe systems in process plants, you could use air but due to the large amount of stored energy, you all only allowed to test to 110 percent of the design pressure. With water you test to 150 percent.

Since the pressure relief systems typically are set at the design pressure with a 10% accumulation, you have a test and system with no safety factor.

To sum up, you get a better test and a safer system with a water test.

Answer 3

This is a very subjective question. What type of pipeline system? I work with chemicals that react with water we never use water in anything to test for leaks. Are you talking automotive household sewer lines? what? To me i would test using water because it is a lot easier to find a water leak and even to follow a water leak. Compressed air requires well a compressor and a air tight fitting. Depending on the application water is much easier to use you might not even need a water tight connection just fill the line and look for a leak where with air well without pressure you would never know and most houses have a source of running water but not a source of compressed air.

Answer 4

Manufacturing term for ASME and DOT requirements is "Hydro Testing". Water will not change volume with compression. Water will not increase it's volume dramatically when compressed to a very high pressure. Therefore if the pipe bursts under extreme pressure, the pressure is relieved with just a very minimal amount of water. It may get the tester wet, but it won't blow the building up or shred the tester with broken shards of steel pipe. Compressed air is extremely dangerous because of the increase in volume to create extreme pressure. A lot of air must escape to get the pressure back to 1 atm.

Answer 5

You can run up a lot of water pressure easily and quickly, and if the pipe fails, it doesn't go far. If you use a lot of air pressure, which takes a pump a long time to build up, you accumulate a lot of air, and if the pipe fails you may find parts of it on Mars! Water is safer. Compressed air is very dangerous.

Yes, you can see water and that is a good indicator, but you can hear an air leak, as well.

Answer 6

my answer is more guess, Compressed air is more subject expansion and contraction, with heat changes. Small leaks are harder to detect, where water leaves a telltale sign. Also water unlike air has less ability to be compressed, and will reach and hold a test pressure better.

Answer 7

much easier to locate leaks
safer