The Flowserve Limitorque QXM is a smart, non-intrusive electronic valve actuator with a maximum of 20 drive sleeve turns and is specifically designed for any limited, short stroke, light torque rising stem valve application. It utilizes the same non-intrusive, absolute encoder technology as does the quarter-turn QX electronic actuator.
Applications include choke valves and small control valves in upstream oil and gas, water and power markets up to 20 drive sleeve turns. The QXM encoder is the same one used in the Limitorque QX. It employs system-on-chip technology, which permits redundant, 12-bit resolution over 20 total turns or an accuracy of better than 2 degrees of rotation. This redundancy feature is part of the B.I.S.T. (built-in-self-test) feature of the QX and MX.
QXM also utilizes the same brushless direct current (BLDC) voltage motor as the innovative QX smart actuator. The use of a BLDC motor will meet most global voltage requirements without the need to change motors. This unique feature is an advanced technology which eliminates sparks, reduces mechanical and electrical noise, and dissipates heat better than DC motors with brushes. A BLDC motor lasts longer than conventional motors and allows for more accurate positioning. This is especially important in functions which require choke valves and control valves. The use of a BLDC motor in conjunction with the absolute encoder assists in providing the precision that users are demanding in their processes.
The Limitorque QXM is available for limited multi-turn valves that require a minimum of 18 ft-lb (24 Nm) to a maximum of 250 ft-lb (337 Nm) of torque and from 3–24 RPMs.