Solutions for the safety of plants

Proxess presents two product lines developed by United Electric Controls: pressure and temperature control transmitters and toxic and combustible gas detectors. All designed for the utmost safety of plants

by Anna Balliana

Proxess, a young and dynamic company, operates in the instrument segment, representing and distributing several brands in Italy. Among these, United Electric Controls, a company which has designed and manufactured pressure and temperature instruments for decades, paying constant attention to the growing concern of companies for the safety of plants. For this reason two of the most recent product lines which it developed are dedicated to this aspect. One is the ONEst safety transmitter line for pressure and temperature monitoring and control, the other is the Vanguard line of toxic and combustible gas detectors. Let us examine them in detail.

Wireless sensors to detect toxic and combustible gases in the air
Such industrial processes as Oil & Gas, refining, chemical production, energy generation foresee the use of toxic and combustible gases, which may give rise to serious danger if released into the air. In order to minimize the risks for the safety of personnel and plants, preventive control devices, such as gas detectors, are positioned; these require costly infrastructures and rarely cover all possible leakage points. All of this is leading to an increase in the coverage of risk zones by means of wireless sensors, with very limited investments. Vanguard is a Wireless Hart® detector powered by two lithium batteries designed to last five years (as guaranteed by the manufacturer), and it is ATEX and IECEx certified as well as certified for use in the USA and Canada. Battery pack and sensor may be replaced directly in the danger area. By means of a lateral button, Vanguard configures, recognizes, gauges and tests the applied sensor. When operating, it sends out, at 8- to 3,600-second intervals, the concentration of gas, temperature, days since the last gauging and power supply tension available, the state of the battery and the network. Easy to use, it fits into al existing Hart® wireless networks, Asset Management Systems (AMS), SCADA supervision systems. Vanguard for now has a non-dispersive infrared ray sensor for Methane (CH4) with a concentration expressed in %LEL (Lower Explosive Limit), and an electrochemical sensor for the detection of Hydrogen Sulphide (H2S) with concentration expressed in 0/100 ppm.

Transmitters for monitoring pressure and temperature
Let us now move on to ONEst, a line of pressure and temperature transmitters, Exida SIL2 and SIL3 certified for the creation of safety systems equipped with instruments. Designed to offer simultaneously sensor and logic solver functions, it includes a safety relay with a contact range of up to 5 A at 250 V. ONEst allows to program the direct control of the final element without converting the signal in 100 msec. The self-diagnosis function foresees a switch control threshold which replicates towards DCS the contact of the safety relay, the control of the 4/20 mA transmitter and also the control of the continuity of the connection between the security relay and the final element, with a 98.5% SFF. Action, tripping differential and state of the contact may be regulated, making this instrument ideal to control pumps, compressors, lubricating systems and filtration systems. ONEst allows the implementation of existing plants with a reduction of overall costs and of the elements involved; a single, programmable device with a local display which besides providing a real-time indication of the magnitude being examined, also shows any self-diagnosis messages. The device’s properties are completed by ATEX, UL and IECEx certifications.