Reliable couplings for a new gas recovery reciprocating compressor package were required by a major global gas compressor OEM. The multi-stage unit featured two motor-driven flash gas compressors and a preliminary motor-driven flash gas compressor scrubber. Three unique couplings were needed to connect each electric motor and corresponding compressor.

The OEM contacted Bibby Turboflex based on a long history of successful collaborations. Bibby provided modified API 670 and ATEX compliant Torsiflex disc couplings to meet the application specifications. Bibby worked directly with the Ship & Offshore Classification Society and its inspectors to reduce lead times while ensuring that the couplings met the DNV compliance requirement. All material used for the couplings’ major torque transmitting components (including hubs, spacers, adaptor plates, and primary coupling bolts) were procured from a DNV-approved mill.

The following Turboflex couplings were supplied, featuring hubs machined to accommodate customer provided shaft end details and torsionally-tuned spacers to reduce overall coupling stiffness. All couplings were balanced to G2.5 and witness tested in-plant.
• Preliminary compressor TF260: 330mm long; 2600Nm max cont. torque; 10,000 RPM max speed
• 1st stage compressor TF400: 380mm long; 4000Nm max cont. torque; 8,500 RPM max speed
• 2nd stage compressor TF750: 470mm long; 7500Nm max cont. torque; 7,500 RPM max speed

Torsiflex couplings are specifically designed for compressor, pump, fan and blower applications. The use of plug-in spacers ensures shaft alignment is always maintained. They are easy to install and remove when maintenance is required, particularly on the bulkhead seal. The couplings also feature spark-free overload protection and an anti-flail design that protects surrounding equipment in the unlikely event of a blade failure.

Highlights:
• DNV compliant
• Torsionally-tuned spacers
• Special-machined hubs to meet customer shaft end requirements
• Innovative AHX hub technology
• Easy to install and remove
• API 670 and ATEX compliant
• Balanced to G2.5
• Witness tested in-plant
• Spark-free overload protection