Water Injection Pump Recycle (Minimum Flow) Valves

Blakeborough BV990 control valve with X-Stream trim for water injection pump recycle application on FPSO vessel

Trillium Flow Technologies (Trillium) has a longstanding history of supplying Control and Choke valves to the offshore oil and gas industry, including solutions for the most critical and severe services, including water injection pump recycle (also known as minimum flow) valves.

Such valves can pose several challenges and result in multiple issues if not properly specified. They are used to recycle or re-circulate the flow from the water injection pump during startup or when there is no forward demand, to maintain the minimum flow required by the pump and prevent overheating. They dissipate the pressure generated by the pump and recirculate low-pressure flow either back to the inlet or, in some cases, dump the water overboard.

The obvious application challenge faced by these valves is the high pressure drop, along with ensuring cavitation is eliminated under all operating conditions. Trillium, with its Blakeborough’s X-Stream trim, offers an ideal solution for this application, providing up to 30 stages of pressure drop to fully eliminate cavitation and ensure the trim exit velocity is maintained to acceptable levels. It is crucial to correctly define the downstream pressure, as overboard valves can sometimes experience a vacuum at the outlet if the downstream piping includes a falling water column.

Another critical function of the water injection pump recycle valve is to ensure tight shut-off. As the valve will spend most of its operational life closed against the full head of pressure from the pump discharge with atmospheric pressure downstream, any leakage past the plug and seat will be erosive. Also, leakage is wasted energy as the pump must make up for this flow.  Blakeborough offers this type of valve in both globe and angle configurations, in cast and forged materials compliant with ASME B16.34 or API6A design specifications.  

Thanks to its flow control expertise, Trillium Flow Technologies can offer guidance on specifying the correct valve for your water injection pump recycle application.

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