Keofitt W9, User Manual, Page: 39 / 50

KEOFITT W9 USER MANUAL V.4 PAGE 39
WARNING!
• When replacing the membrane, set the valve head in the OPEN position before it is unscrewed
and pulled out of the valve body. Omitting to do so may result in twisting and cutting of the
membrane.
• Don't use a big wrench to tighten the valve head to the valve body.
• Don’t clean the valve head in an ultrasonic bath or by immersing it in a degreasing liquid, as it
will impede the proper functioning of the screw action. When in doubt, contact your local Keofitt
dealer.
• When assembling the valve head and body grease the thread slightly with a lubricant
compatible with your production
13.4 Replacing a rubber membrane
The membrane must be replaced a regular intervals determined by the operating conditions of the
sampling valve.
As each application is different the customers must establish their own replacement scheme. Start with
very short replacement intervals, keep the used membranes for refrence and extend the intervals until
the condition of the the used membrane is such that it cannot safely be used anymore. Establish then a
slightly shorter replacement interval to allow some safety margin.
Replacing the membrane is done as follows:
1. Unscrew the valve head as explained in chapter 13.3.
2. Turn the valve head to its CLOSED position.
3. Hold on to the base of the membrane and pull it off the stem
4. Fit a new membrane by pressing it onto the stem
5. Screw the valve head on to the valve body as explained in chapter 13.3