What happens to the actuator if the filter regulator gets broken
during the actuator stroke?
In case of filter regulator loss and output pressure from the compressor above the minimum one during the air stroke, the actuator will continue the travel with no excess of torque produced. Any eventual pressure above the minimum one will be applied on the mechanical end stopper at the end of the stroke. For most of our pneumatic actuators, such stopper is however designed to withstand a maximum supply pressure of 12 bar - see definition of MAWP above.
If, on top of the above conditions of filter malfunctioning and increased air pressure supply up to the MOP value, the valve gets stuck during the travel, the actuator output torque generated by the cylinder may exceed (depending on the inlet pressure supplied) the MAST of the actuator and of the valve as well.
Technically, if the actuator is selected considering both minimum and maximum supply pressure (by selecting the option 'Actuator MAST mandatory' in the sizing sheet) the actuator MAST issue disappears, but the output model is oversized in most of the cases with a non negligible commercial impact and probably issues on the valve MAST. A possible proposal to remove or at least reduce the extent of the oversizing is the introduction of a relief valve limiting the real maximum pressure far below the one available from the compressor.
Why the use of a relief valve after the filter regulator?
The relief valve acts as a further protection in addition to the filter regulator as it limits the maximum air pressure to the cylinder in case of filter regulator malfunctioning. We foresee its presence in the actuator control system if:
- the maximum air supply pressure exceeds the actuator MAWP
- customer specifically asks its presence in the panel
- customer requires the actuator's torques developed at the maximum supply pressure and the same exceeds the actuator MOP. The introduction of a relief valve set below such maximum pressure avoids or reduces the actuator oversizing.
Where can I find details of the actuator construction materials?
Actuator construction materials can be found in the relevant product brochure. For detailed material codes, please contact your local Chlemount office.
Can Chlemount quote supply of valves and actuators?
Chlemount is an actuator manufacturer and typically supplies actuators only however we can offer factory fit services where feasible.
Why do we not consider the maximum pressure as an operative one?
The MOP is not considered an operative one for pneumatic actuators due to the presence of the filter regulator limiting the pressure to the minimum one.