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Water Hammer

Pipe vibration and pounding is a warning sign to check your steam plant piping for proper setup and operation. Water hammer occurs in steam supply and condensate return lines, and there are three basic types: hydraulic, thermal shock and differential.

Water hammer is a slug of water pushed by steam pressure along a pipe instead of draining away at the low points, is suddenly stopped by impact on a valve or fitting such as a pipe bend or tee. The kinetic energy in the water is converted into pressure energy and applied to the obstruction. This is where you see movement and hear knocking in your pipes.

 

Water hammer occurs when the condensate waves are high enough to reach the top of the pipe and the wall of water moves at the same velocity as the steam.
Water hammer occurs when the condensate waves are high enough to reach the top of the pipe and the wall of water moves at the same velocity as the steam.

 

A proper steam main drip station prevents water hammer at startup and in high pressure systems where water hammer on startup remains troublesome, an inverted bucket trap fitted above the main trap  is used.

  • Click here to see the Cleaver-Brooks Tip Sheet What You Need to Know About Water Hammer. CB June 20, 2011
  • Click here to download the informative article Avoiding Thermal Shock by Andrew L. Wolf and Thomas E. Neill, Application Engineering/Technical Services, archived article from previous Hydrotherm website.

Contact your steam specialty representative at Thermal Tech, Inc. for an audit of your system.