An effective way to avoid valve control and pump displacement sensing failures

NewTek’s Linear Variable Displacement Transducers (LVDTs) are now available in an isolation tube format to enable operators to achieve the most reliable displacement feedback of hydraulic or non-hydraulic pumps and valves. The isolation tube defends the LVDT core against the pitfalls of operating reliably in pressurised conditions and fluids when the sensor monitors pump flow or valve position (open/closed). The position sensor provides electronic data as an integral part of an efficient process control system.

When using NewTek’s new isolation tube configuration, only the protected LVDT core lies inside the harsh area or media. The metal core can withstand exposure to a wide range of fluids and pressures so that the likelihood of LVDT core failure is almost zero. The sensor windings are located in near ambient conditions so there is unit failure is highly improbable. In the unlikely event of a failure, the AC-operated LVDT is accessible without the need to disassemble a complex valve housing. The housing is simple to replace while the core remains inside the valve.

For operators who want to monitor the position of a hydraulic valve stem but have no room for a vented LVDT or the budget for hermetic feedthrough, the isolation-tube configuration offers a cost-effective and efficient alternative. The isolation tube offers a great improvement to venting an LVDT because operators do not have to run electricals out of the sensor through a high-pressure header or feedthrough. The protected core can withstand levels of temperature and pressure that are problematic for vented LVDTs.

AC-operated LVDTs offer the perfect solutions for valve and pump displacement sensing as the material between core and housing can altere the sensitivity of pre-calibrated DC units in highly pressurised conditions. As well as providing a range of standard AC-LVDTs, NewTek also customises sensors to accommodate a particular tube or calibrate with a smaller core enabling an LVDT to fit into smaller spaces.

The Newtek NTC600 LVDT signal conditioner powers AC-operated position sensors, providing a digital output in a voltage, 4-20 mA current, or RS-485 digital format. This smart signal conditioner self-diagnoses, monitoring for LVDT failure, disconnects, or short circuits and provides cybersecurity lockout and tamper detection.