TRG Model features the use of a hermitically sealed proximity switch, permanent magnetic field and hemispheric ally shaped pressure balanced probe for bi-directional operation. The entire detector assembly is housed within stainless steel and is pressure balanced without the use of any dynamic seals. It is designed for installation on expiating pipeline. In service under pressure or for new pipeline and may also be installed above or below grade. It also may be adjusted or serviced under pressure condition. Utilizing stainless steel components and assembled by means of welding, the detector having only one moving part (the probe) insures its condition operation without requiring maintenance. Once installed and properly adjusted, the detector is service free.

 The detector is actuated when a pigging device (cup pig, polyurethane foam pig or sphere) in passing causes the probe those projects to the I.D. of the pipe to be displaced. This displacement of the probe from the I.D. of the pipe raises a balanced magnetic field into the vicinity of the proximity switch. The switch housed in the calibrated tube upon being influenced by the magnets closes completing the electrical circuit.

The TRG detector switch model TRG-300-S is hydrostatically tested at the factory to a minimum pressure of 3000 psi.