Change in process condition resulted in pump failure

Cause & Consequence

• Release of a harmful substance

Incident Location

Fixed Installation

Incident Activity

Production operations

Incident Info Source

paul.whittle@c-a-m.com

Specific Incident Equipment

Condensate Sampling and Analysis System

Lessons Identified

Pump shutdown systems should be checked during commissioning, to ensure that both high and low power trips are correctly set.

Incident Recommendations

As a result of this incident, we recommend that operators of similar appications ensure that:1.Ideally the system is not operated during transient conditions2.Suitable protection is provided against the effects of gassing in the suction line/pump. This will comprise (but not be limited to):•Pressure switches, •Flow switches and •Motor load monitoring. Please note the transient nature of abrupt and potentially cyclic changes in processes renders it necessary to ensure that response delay for a gas locked/slugging/priming to a pump should be eliminated. A load monitor should be set with NO delay on the “low” current trip point and the “high” current trip point MUST be set within +/-10% of actually running load and NOT the full load current as stated on the nameplate of the motor. Note that instant transition from low to high is an immediate indication of failure. In addition, the low flow switch, generally fitted in sampling fast loops, must be set to trip the pump at approximately 80% of the fast loop design flow rate. We also recommend that the HAZOPs for any existing pumps operated in similar process conditions as well as those in sampling systems are reviewed. Pump protection is easy to overlook and we will be happy to work with you to outline the various methods to minimise risk.