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NOV Mono progressing cavity pumps selected as offshore solution

NOV Mono has reported that ten of its progressing cavity (PC) pumps have been ordered for a new fleet of offshore supply vessels that will be used to service drilling rigs worldwide.

The 2000 Series pumps will be fitted to ten new HOS MAX 320 supply vessels which Mississippi-based shipbuilder VT Halter Marine is building for Hornbeck Offshore. The pumps will transfer up to 10.8kg of liquid mud to and from the vessels, which will be offloaded when they reach the drilling rigs.

'This is a very demanding application for any pump,' comments Mono's Chip Strickland. 'Drilling mud is a very aggressive substance that can have high solids content, so the pumps must be able to withstand this.'

The ability to operate at sea was another important consideration. For example, centrifugal pumps require a fairly stable level of pumped media to work efficiently. The motion of the sea can cause the mud levels in the vessels to fluctuate constantly and this would have reduced the efficiency of a centrifugal pump, leading to longer offloading times and expensive delays. However, the progressing cavity action of the Mono pumps is not affected by these changing mud levels. This allows the vessel operator to accurately predict the time needed for offloading and get the vessels heading back to shore for the next load as soon as possible, without costly delays.

Mono's high-performance 2000 Series pumps are designed to provide a low cost of ownership. The company's proprietary 2000 Series gear-type universal joint design minimises wear and accommodates both radial and thrust loads. This allows the pumps to handle abrasive materials with over 80% solids, while still maintaining a steady and consistent flow. The range also offers performance capabilities to 4,500 GPM, with pressure to 1,500 psi.

Both cast iron and stainless steel models are available, with a choice of materials and coatings for rotors and stators, to suit individual applications.

'The 2000 Series pumps also have a low running speed capability which extends both the maintenance intervals and the overall working life. That pays particular dividends on an application like this where the pumped media is so abrasive,' concludes Chip Strickland.

The pumps will transfer mud at volumes up to 1,000 GPM, handling pressures of 200 psi. The order was secured through Mono's partner company, Chemetec Engineered Equipment.