Rugged Pressure and Temperature Switches for Nuclear Power Stations

September 29, 2009. With the series ZPN, ZDPN and ZT, Baumer offers very robust pressure and temperature switches developed especially for the use in nuclear power stations. The pressure switches are suitable for pneumatic or hydraulic control, for power generation safety equipments and for pressurized chambers control. They are resistant to short duration overpressure and show a good vibration resistance. The ZPN can measure a gauge pressure from -1 bar up to 600 bar with a very small intermediate range from -2 mbar up to 10 mbar. The ZDPN measures a differential pressure from 2 mbar up to 120 bar.

The pressure switches maintain a constant pressure around a chosen set value. When the pressure reaches a critical pre-set value, they trigger an alarm or safety system. A flexible diaphragm actuates a micro-switch via a piston. The set point adjustment is realised via a compressible spring mounted on the opposite. Due to the force-balance principle, the dead band setting remains constant, even with different set point adjustments. With rapid pressure variations, an attenuator should be used to prevent a temporary on- and off-switching.

The ZT temperature switches are suitable for all fluids and measuring ranges between -45°C and 350°C. They maintain a constant temperature around a chosen set value and act as regulator of an alarm or safety system when the temperature reaches a critical pre-set value.

The pressure and temperature switches ZPN, ZDPN and ZT offer a very good repeatability (±1% F.S.) making them suitable for all demanding applications. The devices comply with ATEX 94/9/CE requirements for the use in hazardous areas; they are available in an intrinsically safe and an explosion-proof version. Approved by the French electricity board EDF, they are used in nuclear power stations all over the world.