High pressure but low cost for CHP from KV Process Controls

KV Process Controls has integrated safety shut-off valves into a control system for a customer in the combined heat and power plant (CHP) industry that has resulted in significant cost savings whilst increasing the system's operating limits.

The valves were required to be used in natural and LPG fuel lines, from 0 to 10 bar, to feed burners in CHP installations. However, the price of the previously used gas valve was making the cost of the systems too high for the customer. Further, the customer was unable to source valves approved to EN161 that could operate up to 10 bar.

KV Process Controls responded to the problem by providing approved safety shut-off valves capable of operating at the required level. The company also integrated the valves into a double-block arrangement, with the second valve in each pair being provided with a proximity switch to confirm positive proof of closure.

The valves used in this application are solenoid-controlled and feature force-pilot operation, which combines direct action with servo assistance. As maximum security was particularly important for this type of application, KV Process Controls supplied valves that were capable of reliable operation from 0 bar.

With the use of the safety shut-off valve in the design of the double-block, it was necessary to integrate a less powerful solenoid than an equivalent direct-acting valve. This was achieved through the incorporation of low-consumption solenoids, which are also easier to interface with the electronic control system. In the event of power loss, the valve is designed to fail to the safe state - normally closed operation, meaning that the solenoid must be energised for the valve to open.

KV Process Controls' type 43 safety shut-off valves use BSP fittings and are available in sizes from 0.5" to 1.5" with EN161 approval. In current applications, the valves operate at 10 bar, but they are available for use up to 40 bar. As standard, all EN161-approved valves from KV Process Controls are fitted with proximity switches for remote confirmation of closure.