When Compressors Operate Outside Design, Communication is Key

Part 6 of our 6-part blog series, What you Need to Know About Reciprocating Gas Compressors
by Randy Franiel, Compass Senior Accounts Manager, Canada

This is the sixth, and final, blog in my series on understanding reciprocating natural gas compressors. We’ve spent time exploring shaking forces, volumetric efficiency, compressor selection, and more.

Operating a compressor within its design envelope should produce an amount and type of vibration (i.e. force) that won’t put excessive strain on its components. If it’s operating as designed, it should perform as designed.

On the other hand, if a compressor is seeing excessive forces, there’s a good chance it is operating outside of the range the unit was designed. Sooner or later, the unit will break down and that’s expensive.

One of the most common scenarios is when a unit that was designed with double-acting cylinders is being operated as a single-acting design.

It’s understandable how this happens. Often times, there can be a gap of a year or more between the producer buying the equipment and getting it out in the field and running. Conditions can change, leading producers in some cases to adjust by switching from double- to single-acting.

A vibration assessment, conducted on-site by trained personnel, is a wise investment in the start-up phase of a newly installed recip gas compressor. There’s a cost, of course, to sending out someone who’s qualified to do this assessment. For this reason, I’ve been investigating the value of monitoring equipment though high-speed video for our customers. This could ultimately be another tool we can use, along with the vibration specialists we work with regularly.

Not long ago, one vibration assessment we carried out yielded a valuable insight. While the skid and the mounting of the equipment were both rock-solid, one section of piping was vibrating excessively. If this continued uncorrected, there’d eventually be a breakdown and accompanying downtime while the equipment was serviced.

In this case, the client had configured the machine to run with all four cylinders single-acting, when they were designed to operate as double-acting.  Knowing that, we can take steps to remedy the situation. We ended up taking two cylinders off completely and made the other two cylinders run double-acting. That reduced the vibration down to an operationally-acceptable range.

In working with producers, it’s understood that operating conditions can change between the purchase and installation of equipment. If conditions change, keeping your compression provider in the loop will allow them to make changes to the package to keep it running smoothly.

Would you be interested in attending a Compass Technical Conference
on gas compression and processing? 

Please let us know, by answering just one question here: Technical Conference

If you have any questions, or would like more information,
please contact the author, Randy Franiel, at 1-855-262-2487.