The standard protective cover protects the internal micro switches and the springs against outside influences. In addition, it ensures that the oil flows out in a defined way during operation. The cover is made of sea-water-resistant aluminum. When the operating pressure is reached, the plate lifts up to create an opening through which gas or oil can escape. The aluminum signal pin raises and operates the micro switches. The defined stroke allows the contacts to react within 2 ms. The pin adjusts its position while the pressure relief device closes securely.

Messko Pressure Relief Devices are available in a range from 5 to 30PSI (0.41 to 2.07bar). Electrical connection can be implemented with cable glands or a terminal box. ANSI and Westinghouse connectors are also available for the North American market.

The Pressure Relief Devices is also available with an oil-directed cover.