A manufacturer of quick release fasteners have been using AKO black plastic general purpose Pinch Valves for sodium hydroxide (product code VMP025.03XK.72) on a machine for 20 years. The Pinch Valves were already part of the machine design, and have continued to work at a high standard, improving the overall operation of the machine.
Product: Diluted Sodium Hydroxide solution (25%) and a degreasing solution.
Pressure: No pressure (gravity fed)
Amount of pressure being used to shut off the valves: 6 BAR
The Pinch Valves are normally closed.
Amount of Cycles per day: The machine runs for 24 hours per day. Each machine cycle is 1 hour.
There is no degree of vacuum being used with the Pinch Valves for sodium hydroxide.
The engineer on site of this manufacturing premises quotes his overall satisfaction of the AKO Pinch Valve as:
“Very satisfied. The pinch valve is good quality at a good price.”
Since AKO Pinch Valves only need 2 – 2.5 BAR above the line pressure to fully close, we recommended to the engineer that the control pressure should be reduced from 6 BAR to 2.5 BAR if possible. Using too much pressure to close the sleeve than necessary can shorten it’s lifetime.
The engineer currently purchases spare natural rubber sleeves for the valves for sodium hydroxide (product code M025.03XK), to keep on the shelf in case of any failures. We suspect that the sleeves will perform better for a much longer period if the control pressure is reduced.
For further information about the recommended pressures for operating Pinch Valves, please see typical pinch valve failures.