Mitigate hydrate formation with methanol or regenerated MEG

PULSE HF high-flow ultrasonic chemical injection metering valves (CIMVs) are designed for injection of monoethylene glycol (MEG) and methanol as part of a subsea hydrate mitigation strategy. They have been developed to handle the contaminated regenerated MEG stream.

At the heart of this CIMV technology is a large-bore, nonintrusive, line-of-sight ultrasonic flowmeter. The robust, particulate-tolerant nature of these high-flow CIMVs means that no subsea filtration of the MEG or methanol is required.

Obtain accurate measurement with very low pressure drops

The large-bore, line-of-sight flowmeter fires an ultrasonic pulse with and against the flow, measuring the difference in time of flight in the two directions. The difference in times indicates the speed of the fluid, enabling the flow rate to be accurately calculated. As with the PULSE LF low-flow ultrasonic CIMV, a secondary flow measurement system is supplied as standard; it consists of two pressure sensors across the throttling valve and a rotary variable differential transformer (RVDT) to provide valve position. Processing at the system level can then be used to convert the data to flow rates.

Precisely regulate flow

The PULSE HF CIMV uses field-proven multiple orifice valve (MOV) choke trim technology to provide an erosion-resistant throttling element. The MOV trim consists of two sintered and hot isostatic pressed (HIP) tungsten carbide discs, one fixed and the other rotated by a stepper motor via a gear train. Both discs have specially shaped, extended-range orifices that when rotated relative to each other, easily achieve a turndown ratio in excess of 135:1 with very fine system adjustment.