Water hammer was normally seen in many situations such as the flow of liquid, gases and even steam, due to the momentum of the water in motion is suddenly transferred to the piping and their supports when valves are shut abruptly. It occurs because once a water valve is shut abruptly, the still flowing water has nowhere to go and in order to stop the water from moving, the piping is forced to absorb the water’s momentum. In most steam system, if steam shut-off valve is open too quickly will cause the steam rushed into the cooler downstream pipe and condensed into water immediately. Find the right type of flow meter could help to detect and reduces the unnecessary costs.
When the condensate reaches the bend or equipment of the pipe, the velocity becomes standstill, and makes all kinetic energy will be released to the pipe wall in the form of pressure. The pipe will break if the speed of the water hammer is high, or the quality of the condensate is very large. Even if the speed is slow or the quality is small, it will produce a lot of noise and vibration
Steam hammer will damage other valves, like, filter valves, steam stop, and sensors, but they are preventable. Below ways you can avoid water hammers in your steam pipes:
- Water hammer caused by opening and closing the valve too quickly. Increase valve opening and closing time.
- Centrifugal pump and coagulation pump should stooped when the steam stop closed 15%~30% instead of fully closed.
- Steam piping or equipment must select the correct trap and displacement.
- Drain station must be installed at the low point of the steam pipeline.
- Install steam trap station and air exhaust station at the end of the steam pipeline.
- If all condensate in the system is recycled, a check valve must be installed after the trap.
- Avoid condensate from different pressures being recycled to the same pipe.
By and large, steam water hammer is not only a system design issue, but also a security matter. Water hammer will not only significantly increase the maintenance and downtime of equipment and systems, seriously affect normal production, and cause economic losses to the enterprise. It can even cause safety accidents and cause harm to people.