How to choose an actuator for 8,000 switches per day?
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As the title indicates, it’s a single-operating-condition setup with two pneumatic shut-off valves, one above and one below; they need to be operated 8,000 times per day. The standard rack-type double-acting pneumatic actuators have a very high failure rate. Due to time constraints for operation and explosion prevention, electric actuators are not considered. Due to the product quality requirements that prohibit exposure to high temperatures, a rotating discharge valve is not considered. There should be no issues with the selection of the valve body itself; various factors related to the valve body will not be considered for now. Dear experts, please recommend pneumatic actuators suitable for similar working conditions that you have found to be effective. Thank you first~
Come and learn*, wait for the experts to reply. It seems that many of the pneumatic valves on packaging machines operate more than 8,000 times per day, yet they don’t seem to break down often.
All double-acting cylinders of the sulfur packaging line and polypropylene packaging line achieve more than 8,000 cycles per day without any issues； The discharge valve of the three-reactor polypropylene system is operated by a single-acting cylinder once every 50 seconds; the manufacturer provides a three-year warranty, yet it has actually been in use for over 4 years!
With such a high frequency of operation, the cylinder itself is not the main issue; the problem lies in the valve body, particularly the packing seal or interference fit at the shaft sleeve. Frequent operation causes rapid wear in these areas. If the medium is a pressurized gas or liquid, leakage can easily occur from the valve shaft sleeve
Thank you! Conventionally, fork-type mechanisms are often used for large-diameter, high-torque valves, while gear-rack types are preferred for applications with light loads such as powder packaging. Moreover, the fork-type mechanism also involves many mechanical connections for transmission; could this lead to a higher failure rate under frequent operations? We perform an action roughly every 10 seconds on site.
Since it is a solid powder, the main problems and failure rates still lie in the actuator.
The small cylinders of the packaging line F-E-T-S-O, and the large cylinders of the discharge valve in the polypropylene three-reactor system M-E-T-S-O – they are very useful. The gear and rack are not wear-resistant; the material of the shift fork is important, and it requires high torque to open and close.
Okay, let’s give it a try. Thank you for your support!