we have a problem with water hammer on a condensate system on a chemical plant. Joints an valves are starting to leak, is there a way to stem this problem
Waterhammer can be caused from a variety of sources e.g. valves closing or opening too quickly and poor piping layout. Usually it stems from a rapid step change in fluid velocity resulting in a pressure spike and the system needs to be analysed to discover how this could be happening. Normally a hydraulic computer analysis is run by a competant consultant to check the avoidance of hammer under transient conditions.
A basic check would include reviewing closure / opening times of valves and understanding what causes velocity changes within the system. There could be column separation due to poor piping design which can aggravate the waterhammer phenomenon.
Make sure steam & condensate piping is pitched down towards the trap. Water that pools within the piping will create water hammer from it being driven by the steam when they eventually block the steam passage.
Assuming this is a steam condensate system, is the system pressurized or open to atmosphere. Sometimes on systems open to atmosphere or operating at low pressures, the condensate temperature can be so high that the condensate is continuously flashing and condensing in the piping causing the water hammering. This can be dramatically increased at pressure reducing areas (control valves, throttling valves, etc.).
If this is the case, you need to find a way to either cool the condensate or increase the system operating pressure slightly, if possible.
For pressurized systems, sometimes the problem is leaking steam traps allowing steam into the condensate system. Or it may be a poorly operating heat exchanger (fouled or excessive flows) which is not condensing all the steam and maintaining a liquid level. Again this would let hot steam into the condensate system causing hammering.
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