Maersk stipulated a maximum noise level for the pumps of 80db(A) – compared to the broadly accepted maximum for continuous exposure over an eight hour day of 85db(A).
Alderley, which took on the plant contract, approached Amarinth to supply the necessary API 610 OH2 pumps with Plan 53B seal support systems –meaning that Amarinth had to meet the 80db(A) noise levels requirement – and on a tight 28 week delivery schedule.
Amarinth managing director Oliver Brigginshaw says that to meet the design standard, its pumps' noise levels would have to be reduced. Although the motor noise was within spec, noise at the wetted-end was too high.
So Amarinth designed a bespoke baseplate placing the pump and motor on the left and the seal support system, with its air cooled piping, on the right – enabling the firm to build a compact acoustic enclosure just for the wetted end of the pump.
"I am sure we will see more requirements for innovative designs like this to meet tighter regulations in the future, and we look forward to working with the oil and gas industry to deliver against these," comments Brigginshaw.
For ease of maintenance and full access to the pump and motor, the acoustic enclosure is quickly removable without the need to disrupt pipework, he says.
However, it also had to remain in-situ near the pumps when removed as there was nowhere else to move it to on the rig.
This required modelling the human elements during the design stage to determine how people could work around the enclosure effectively.