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Q Are pinch valve sleeves resistant to diffusion?
A Although pinch valve sleeves are considered technically leak-tight, a diffusion of slightly volatile gases is still possible and cannot be ruled out.
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Q What is the maximum pressure which the pinch valve sleeves can withstand?
A The maximum operating pressure of the pinch valve sleeves depends on both the pinch valve types and the pinch valve series;
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Q How are your pinch valve sleeves manufactured?
A The sleeves of the air-operated pinch valves are manually assembled in the production process and then machined in several additional work steps into the final product. The entire process is very labour-intensive and accompanied by high wage costs. Therefore, among other things, the prices of the air-operated pinch valve sleeves cannot be compared with those of a piece of tubing in an extruded hose.
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Q How do your pinch valve sleeves differ from those of the competitors?
A We use only premium additives in our elastomer mixtures. Thanks to many years of constant improvements in both the elastomer mixtures and the structural design of the sleeve, we have succeeded in applying our experience in the area of pinch valve control to increase the service lives of the pinch valve sleeves and thus the "Best total cost of ownership" to a maximum, resulting in a customer satisfaction level of 96%.
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Q How many switching cycles can a pinch valve sleeve withstand?
A The possible switching cycles of a pinch valve depend on numerous factors and operating conditions such as the control/closing pressure, the media/operating pressure, the operating temperature and the operating medium. Unfortunately, no general statement can therefore be made about the switching cycle frequency. Thanks to our rich experience, however, and dozens of different applications, our sales team is able to estimate the switching cycle frequency based on information on all of the usage details for each pinch valve size and design; simply contact us with your usage details and we will be able to provide you with a rough estimate regarding the service life for your application. It can generally be said that the possible number of switching cycles drops as the pinch valve sizes and nominal widths increase. In our constant in-house endurance tests, the sleeves achieve from 50,000 to several million switching cycles depending on their size / nominal width and the control/closing pressure level. Feel free to contact us with your application details. We will then be able to provide you with a rough estimate of the switching cycle frequency for your application.
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Q Can a pinch valve sleeve simply be trimmed off so that it fits into a different brand product?
A No. The sleeves are structurally designed for our AKO pinch valves. External changes make them unsuitable for usage in pinch valves. Please contact us with the concrete deviating dimensional requirements of the pinch valve sleeve and we will be happy to advise you.
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Q Which pinch valve sleeve should I select for my medium?
A The selection of the most suitable sleeve material always depends on the operating medium and the operating temperatures. It can generally be said that natural rubber is best suited for all bulk materials, sludge, dusts, suspensions with operating temperatures < 80°C without chemical additives and/or with no requirement with respect to chemical resistance. A design/specification should be made by our sales team for all other operating media having particular requirements such as those regarding chemical resistance, foodstuff compatibility and/or higher operating temperatures. Please do not hesitate to contact us at any time with your application details/requirements.
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Q Can I also use grease instead of assembly paste when replacing a pinch valve sleeve?
A No. In addition to making the installation process easier, the assembly paste also ensures a tight fit of the sleeve in the clamping. Grease has the opposite effect and in the worst case, for example in contact with NR elastomer, can cause the NR elastomer to swell and decompose.
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Q Troubleshooting
A Trouble | Possible Causes | Remedies |
The pinch valve is not closed or not closed completely | No control gas is available | Check air supply |
Check whether the control air enters the pinch valve |
Control valve failure | Check/replace the control valve |
The control pressure is too low | Check the optimum control pressure to be set |
Inner bushing is damaged | Replace inner bushing |
Inner bushing is not lip type closed | Use the mounting plate to correct the closing image of the bushing |
The pinch valve is not open or not fully open | The vent hole in the control valve is blocked | Clean the muffler/control air line |
Vacuum in the delivery area | Vacuum control |
The pinch valve closes for a long time | Open the vacuum support |
Control valve failure (not close) | Check/replace control valve |
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Q Troubleshooting
A The bushing wears out quickly | Control pressure/ differential pressure is too high | Check the optimum control pressure to be set |
The cycle (on/off) is too fast | Extend cycle time |
Turbulence in delivery pipe/pinch valve is too close to elbow | Change layout of the pipe or pinch valve (minimum distance to elbow) |
The pinch valve does not close completely | Check the optimum control pressure to be set |
Adverse operating conditions (such as high temperature, high working pressure or flow rate) | Change operating conditions |
Pinch valve opens/closes too slowly | See trouble “pinch valve opens/closes too slowly” |
Vacuum in the delivery area | Vacuum balanced |
The inner bushing quality is not suitable for conveying medium | Use other kind inner bushing |