Actuator position monitors for China

Edited by the Processingtalk editorial team Mar 10, 2006

K Controls have delivered more than 350 ATEX certified intrinsically safe 007 Switchboxes used to monitor the open and closed positions of pneumatically actuated ball valves in a major new refinery

K Controls have recently completed the phased delivery of more than 350 ATEX certified intrinsically safe 007 Switchboxes that are used to monitor the open and closed positions of pneumatically actuated ball valves in a major new refinery in China.

The switchboxes are used in zones where hazardous gases may be present and are fitted with two "failsafe" solid state intrinsically safe proximity sensors.

"Failsafe" sensors when used in conjunction with "failsafe" signal evaluation devices can significantly improve the safety integrity of a valve monitoring system.

Should there be an error in the sensor, evaluation device or the interconnecting cable the output of the evaluation device is always switched automatically to the safe "OFF" condition.

Very high quality components are used in the construction of the sensors which have been tested and certified by TUV in Germany.

The aluminium switchboxes have a polyester coating inside and out, an ingress protection rating of IP677 (dust proof, water proof and 6 joule impact protection) and full ATEX certification to II 2 GD EExia IIC T6/T 85C.

They can operate in an ambient temperature range of minus 40 to plus 45C.

The internals are accessed via just two captive screws and the cover is slanted to give good access to both the terminals and the sensors.

The cams for the sensors are spline driven and can be quickly and easily adjusted without special tools.

Each cam has a raised profile of 180 degrees making it possible to set a sensor so that contacts in the evaluation device are either made or broken at the end of travel.

The output shaft is stainless steel and the mounting arrangement conforms to the VDI/VDE 3845 FO5 standard for rotary actuators.

This enables the switchboxes to be fitted to a wide range of different actuator types and sizes using one of four standard stainless steel mounting brackets.

Situated in southern China, not far from Hong Kong, the petrochemical complex will supply more than 2 million tons a year of products such as ethylene, glycol, polypropylene and polyethylene to customers mainly in the domestic market in China.