Too much closing pressure
The differential closing pressure should only be around 30PSI to ensure the pinch valve is fully closed and sealed. Any additional pressure is just stressing and stretching the sleeve material, leading to fewer cycles until failure.
When pinch valves are used in vacuum conveying applications, the negative air suction causes the sleeve to partially close. This disturbs the air and particle flow, causing the valve to wear quickly. AKO offers the AKO VAC Accessory to easily solve this problem.
Incorrect rubber sleeve material
A Natural Rubber sleeve was used in a fatty oils application. A Nitrile sleeve should have been used instead.
From a Chocolate application is an example of high temperature damage to a food grade sleeve.
Rubber Sleeve Exceeded Temperature Rating
Natural Rubber Sleeves should only be used for applications up to 175 degrees F, or 195 degrees F if using the High Temperature Rubber Sleeves. For higher temperature ranges, Silicon sleeves can withstand 265 degrees F and EPDM Sleeves can withstand 250 F.
Check out our Documents Section or Videos on best re-sleeve practices.
Caused from a sharp object passing through a valve.
Incorrect Installation of OV Normally Closed Pinch Valve
In this case, the valve should have been actuated to the open position when installing the new sleeve. See correct installation instructions in the Documents Section of our website.