Gestra’s ZK-type is a control valve designed for severe applications. The ZK-type has been proven in operation in power stations, oil refineries, and chemical plants on extreme service applications for many years. It has been designed with a high-quality wear-resistant stage nozzle with zero leakage. The design allows for tight shut-off without compromising control performance. To ensure a tight shut-off in extremely high-pressure applications, the ZK-type is assembled with the tandem shut-off option. It can sustain high differential pressure and critical operating conditions in steam and water systems. The valve’s trim can be removed while the valve is still in the pipeline to reduce maintenance time. If your process condition changes, the ZK-type can adapt to those new conditions by simply changing the nozzle.

The patented ZK Radial Stage Nozzle features several sleeves with a huge number of radial orifices. Those orifices are parallel but shifted from sleeve to sleeve forming nozzles mounted in series with intermediate flash chambers. The flash chambers ensure that the pressure differential across the valve is reduced to a minimum. The noise in the control valves is normally below 85 dBA for the entire control range. In a valve with a differential pressure of up to 100 bar, the sound level is even kept below 80 dBA.