Achieving Pneumatic Cylinder Longevity in Harsh Environments
By Japh Humphries , UK Sales & Commercial Manager , Matara UK Ltd
Pneumatic cylinders are an efficient , reliable and clean solution for moving loads in a linear direction ( back and forth or up and down ), with good levels of force and speed .
Cylinders are often the most important component of a linear motion system . If the cylinder fails , the linear motion system is unable to function . In a harsh environment where contaminants are heavily present , standard cylinders are going to fail all the more frequently , resulting in greater downtime . Cylinders can be contaminated internally from the air supply or externally from the operating environment .
What environmental factors impact cylinders ’ longevity ?
Airborne particles in the form of dust and grit are the most obvious threat to cylinders . If this penetrates a nose seal , it builds up and sits in seals and bearings with a similar effect to sandpaper . In a normal environment , with regular preventative maintenance , standard cylinders can cope well with basic levels of dust , but where these contaminants are prevalent , such as flour mills , a more robust cylinder must be considered .
Water may not be deemed a contaminant in the usual sense , but when it comes to pneumatic cylinders it is very much a problem as where there is compressed air , there is water vapour . Furthermore , in the food industry where washdowns are conducted regularly and very thoroughly , the water collects within system components where it can block the flow of air through orifices , dilute or adulterate lubricants , corrode the barrel or rod finish and , of course , freeze in cold weather . 14 FDPP - www . fdpp . co . uk
Water may not be deemed a contaminant in the usual sense , but when it comes to pneumatic cylinders it is very much a problem as where there is compressed air , there is water vapour .
Contamination from synthetic oils used to lubricate the air compressor can have a similar impact on cylinders to water . In harsh environments , greater quantities of lubricant are often used , which makes the contamination situation worst .
In applications where extreme heat is used , the piston rod and rod-seal are prone to damage .
So , these are the problems , but what are the solutions ?
Selecting a cylinder for harsh applications
For harsh environments you will need to look to a more customised cylinder , but most of these are relatively straightforward and represent a good ROI .
Let ’ s start with the cylinder seals , these being one of the most important means of preventing the ingress of dirt and water . Standard seals can be replaced with specialist versions to meet the needs of your specific application . Viton™ - a fluoropolymer elastomer and synthetic rubber compound - seals , for example , have been designed for use in some of the harshest environments , where temperature extremes are common . These can readily be used in Matara ’ s standard rod type pneumatic cylinders and rodless pneumatic cylinders .
Moving further into the cylinder construction , with rod type pneumatic