Garlock valves now close with nearly half the power

Garlock GmbH reduces the torque of its PTFE-lined valves – actuators can now be sized smaller, maintenance made easier

Garlock GmbH presents its evolved Butterfly actuators at Valve World in Düsseldorf. Thanks to evolutions in the liner and disc, friction values were reduced to the point where significantly lower torques are required to shut off or throttle the flow. For instance, the torque of the DN80 valve was lowered from 48 Nm to 29 Nm (a reduction of 40%). At larger diameters, it was possible to reduce torque even more. For the DN300, now only 274 Nm are needed instead of 520 Nm (a reduction of 47%), whereas the DN600 now only needs 2,056 Nm instead of 3.990 Nm (a reduction of 48%). These statements are based on extensive measurements – measured dry at 21°C. Thanks to the product refinement, Garlock valves now feature the lowest torques on the market.
When maintenance is required, case liners and flap discs made from other materials can now be more easily exchanged for parts made from high-quality PTFE, which offers better chemical, abrasive and thermal resistance, all without having to replace the actuator. This is because Garlock was able to compensate for the higher coefficients of friction resulting from PTFE-on-PTFE contact by using the new liner technology. For example, now it is generally possible to replace a valve with a PFA liner and PTFE disc with fittings consisting entirely of PTFE. In the past this proved difficult in cases where the actuator was designed for the lower coefficients of friction resulting from PTFE-on-PFA.