Mokveld anti-surge control valves can deliver accurate control without over‑shoot and can also respond very fast to avoid compressor surge.
Gas supplied from Algeria to Morocco arrives at the Moroccan border at relatively low pressure, before it is transported to Spain and Europe. A compressor station is used to boost the gas pressure. Each compressor is equipped with an anti-surge control valve which prevents potential damage to the compressor due to surge conditions.
When the gas flow through the compressor becomes very low it may be physically impossible for the compressor to still compress the gas. This condition is generally referred to as the surge condition. A specific control systems is installed to avoid these conditions to happen. The control valve protecting the compressor is the anti-surge control valve. This control valve is closed when the compressor operates normally and opens quickly to connect the inlet and outlet of the compressor when surge conditions almost occur.
Anti-surge and recycle control valve
The same control valve can be used as the recycle control valve, during start-up of the compressor or in case recycling of the flow is required this valve is opened. When the control valve opens it can be considered that the energy dissipated by this control valve is equal to the rated capacity of the compressor. In this case this is 16 MegaWatt. The control valves are installed outdoor and therefore the maximum sound level is 85 dBA.
To prevent damage to the compressor, Mokveld supplied highly reliable very fast acting control valves. The instrumentation on the control valve is designed such that upon an emergency case the valve can open in less than 2 seconds. The same instrumentation is able to smoothly and accurately position the control valve during recycling, start-up or surge control at the same speed.
Fully pressure balanced design
The Mokveld control valves can deliver accurate control without over shoot and can also respond very fast to avoid compressor surge. The full pressure-balanced design of the Mokveld axial flow control valve makes the valve insensitive to the rapid changes in pressure and flow. The SIL3 certification of the Mokveld axial flow control valves confirms that the compressor is safely protected.
Control valves are critical elements in a process loop. Malfunction or failure of a control valve can seriously affect plant operation, the environment and your bottom line. Selecting Mokveld axial control valves with proven reliable performance will help to reduce costly maintenance and lost production time. The axial control valve solutions that we offer today are the evolution of all the valves that have been developed over the past sixty years.
In order to ensure you continue to benefit from valves that offer high capacity and safety as standard, we offer a range of modernisation services. For more information about our modernisation services, please contact your Mokveld support office or representative.