The standard practice for replacing a sleeve in any pinch valve is to remove the valve from the line which requires the use of a crane for all but the smallest valves. The valve is then stripped – the sleeve replaced – and the valve rebuilt. It is then reinstalled in the line – a process that can take several hours at best requiring the attention of several fitters and millwrights.
With the patented Red Roc Hi-Lift feature the valve remains in the line and the sleeve can be replaced in a much shorter time with only two fitters.
On 15 September 2017 at a nickel mine in Mpumalanga a Red Roc valve sleeve was changed in 80 minutes and reduced the plant downtime by at least ten hours.
“The process is simple and only involves removing the bolts holding the top half of the body in the line and slackening the ones in the bottom half. Jacking bolts on the valve flanges spread the valve flanges from the pipe flanges loosening the sleeve, so that it can be removed in line.
The quick release clamps holding the two halves together are removed. The top half is then raised using the two hydraulic cylinders mounted on the bridge and operated by a hand pump. In the raised position the old sleeve can be lifted out and the new one fitted in position.
The process is then reversed with the body being allowed to drop by releasing the oil in the cylinders back to the reservoir – the clamps are refitted and line bolting replaced” said Gregor Hopton, Afrivalve’s Group Marketing Manager.
The Red Roc Hi-Lift pinch valves are manufactured by Afrivalve, a division of eDART Slurry Valves at eDART Slurry Valve’s facilities in Jet Park, Gauteng. The range includes sizes from DN150-DN600. Larger sizes are available upon request.