Problems sourcing pump spares
DONG Energy had been using Girdlestone pumps for many years on its offshore oil platforms in the Siri field, which is located in the North Sea, to pump produced water. The pumps had proven reliable and were well liked, but since the closure of the Girdlestone operation the after market support and delivery of spare parts from the existing channel was proving unsatisfactory and sporadic at best. One of the pumps then failed, leaving DONG Energy’s operating on the standby pump and having to perform unplanned maintenance. There was now a serious risk of the rig being shutdown should the standby pump fail and so time was of the essence to get the original pump back into service. The problem was identified as the shaft, but the existing supplier of OEM parts didn’t seem interested in providing a replacement quickly. One alternative was to ask a local machining shop to make a replica.
The hidden costs in using replicas
Whilst having a replica machined is often attractive from an initial cost point of view, there are usually hidden on-costs. A local machinist is unlikely to know the exact grade of material used by the original manufacturer nor the tolerances that the component was designed to. The consequences of any variance will not be noticeable in the short-term, but the excessive vibration that can be caused by incorrect tolerances will lead to increased noise and the premature failure of other costly components, such as the mechanical seal.
Fully interchangeable components
Turoteknikk, Amarinth’s agent in the region, found out about the dilemma and suggested that Amarinth may be able to assist. Amarinth had already re-engineered many Girdlestone
components to support other companies that were experiencing similar supply issues to DONG Energy. Amarinth also had significant experience of the offshore market.
Speed is of the essence
Although happy to have found a company to provide a replacement component, the risk to DONG Energy of having the pump out of action for the five weeks initially proposed was unacceptable and DONG Energy asked Amarinth if it could be done in just two weeks. Amarinth thought hard about how they could shrink the lead time – the solution involved:
Everything came together flawlessly and new component was on the rig within 10 days from the initial enquiry, a 60% reduction in the required lead time, whilst DONG Energy were kept fully informed of progress throughout.
Assured supply of spares
The replacement shaft, which was fully ATEX certified, performed faultlessly. DONG Energy has since placed orders with Amarinth for other spares. On the strength of Amarinth’s attention to quality and short lead times, Dong Energy has decided to replace three other worn out Girdlestone pumps with dimensionally interchangeable Amarinth A series API 610 OH2 pumps.
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