Non-Condensable Gases (NCG) Compressor Failure
A client reached out to S&S Technical to help them with the catastrophic compressor failure at their geothermal power generation plant. The failure was on their Non-Condensable Gases (NCG) compressor which is responsible for recovering the NCG from the vaporizer. Because there is the potential large amounts of liquid carry-over in this gas stream it is important there is a properly sized suction scrubber with a reliable drain system to prevent these liquids from entering the compressor. In this instance, a large slug of liquid was introduced to the compressor during operation which resulted in the failure.
The horizontal, single-stage, single-throw reciprocating compressor used in this application has very tight piston clearance tolerances. When liquid is introduced to the compressor cylinder – in a large enough volume, there is not enough space left in the cylinder at top-dead-center to accommodate it. The liquid is incompressible and, as a result, a tremendous amount of hydraulic pressure is created and transmitted through the rotating member. In this instance, the amount of pressure far exceeded the rated load capacity of the connecting rods and crankshaft. This intense rod loading caused the connecting rods and cranks shaft to break as well as separated the compression piston from the piston rod.
It was now our challenge to rebuild the compressor and get it back to the client as quickly as possible. The damage to the compressor was quite extensive. The crankcase was damaged, the cylinder was damaged, and all of the rotating member required replacement as well as the valves, piston, packing box and all of the wearable items. It was our goal to rebuild this compressor from the ground up for less money than the cost of a replacement compressor and do it faster than took to get a new unit.
Ultimately, we were able to rebuild the compressor in 4 weeks – 8 weeks faster than a new unit – and save our client $13,000.00! In addition, we provided them a fully tested and run-in compressor, ready for installation that included an 18-month workmanship warranty – 6 months more than a brand new unit.
S&S Technical’s compressor service staff has over a decade of service and field experience which allows us to provide the highest quality workmanship and technical support. Our assembly and testing meets or exceeds the manufacturer’s standards which allows us to provide the best warranty in the industry.