When you run a steam or gas turbine, you need to determine whether or not your equipment needs to be flushed. Flushing a system at the right time will help to prolong its life and ensure that the turbine works at its full potential.
What is a flush?
A flush is the process of cleaning the internal workings of a turbine, or any other machine, with a fluid cleaning agent. Many people fall into the trap of thinking that a flush will be a simple task, but if you are not prepared, this can be far from the case.
How to perform a successful flush
Performing a successful turbine flush is not as easy as it may seem. You will need to think carefully about the process before you get started if you want to do it successfully, otherwise you could cause more problems than the process solves.
A successful internal flush, according to ASTM D6439, is when:
“Clean pipe and system components are obtained in a minimum of time and with a minimum of effort.”
So, when performing a flush, your main aim should be to remove the buildup of old oil as quickly and cost-efficiently as possible. Here’s what you need to bear in mind if you want to achieve that:
High oil velocity
Ideally, you should use an oil velocity two or three times higher than your system’s normal working velocity if you want your oil flush to be a success. A higher velocity oil will very quickly remove any old oil that is lurking around in your system, so that you can start again with a clean slate. However, you should not use high oil velocity with certain very delicate systems, so it’s a good idea to consult the system manual, or someone who specialises in such matters, before you go ahead and clean your turbine.
You also need to ensure that you use a fluid that will not react with the oil it will be flushing, because if both fluids are not compatible, particles that have the potential for damage could be left in the system following your flush.
Finally, once you’ve flushed the system, you will need to use a displacement oil to get rid of any excess cleaning fluid. Remember, to get the most benefit from flushing fluids, be sure to heat them first.