Safety Test Compliance

Submersible pumps are sometimes used in environments that contain dangerous substances. Consequently, the electric motors used in these pumps are subject to stringent safety requirements that they be able to withstand the energy released during an internal explosion, without failing structurally and posing a danger to people or equipment in the vicinity.

Our client had recently made some modifications to the design of one of their motors. Because of this, each of the motor models in the range had to be re-qualified for explosion containment safety. All but one passed the test and since the designs were generally the same, this was unexpected and needed to be understood. If the measured parameters had been accurate and representative, this would have had the implication that a modified design would be required for just one motor in the range. Our client was confident in the validity of their design and so they tasked us with determining why this specific test was showing an anomalous and unexpected result.

By running a CFD analysis of the combustion process that the gases inside the motor housing would undergo in the event of an explosion, it became clear that the design was sound and that the unfavourable test result was due to a measurement problem. With this confirmation in hand, we proposed a small but targeted change that led to the motor being approved in a subsequent test.