FAQ - Mechanical Pinch Valves
In contrast to the air-operated pinch valve, the mechanical pinch valve does not pinch the elastomer/rubber sleeve with compressed air or neutral gases/liquids, but rather by a mechanical process.
Advantages: The opening tabs of the collars permanently connect the mechanical pinch valves to the mechanism, causing them to always return to their initial position, even after prolonged closing, and to open again at their full cross section or diameter.
Mechanical pinch valves are generally better suited for flow or position control. They can also be manually operated by a handwheel and be variably equipped with different drives.
The overall lengths of the mechanical pinch valves vary for each series.
The mechanical pinch valves of the RV series are available in overall lengths in accordance with DIN 3202 F5/F15, ASME B16 long and/or ISO5752 Table 6.
The OV mechanical pinch valves with longer overall lengths are not subject to any standard.
The closing times of the mechanical pinch valves depend on the nominal widths and drives. In principle, the closing times of the electrical actuators are considerable longer than those of the pneumatic drives.
The closing times of the pneumatic drives with factors 1.5...2 are comparable to those of the air-operated pinch valves. Please feel free to consult our sales team about the concrete details of each case.
Yes, the mechanical pinch valves are available with a "fail safe" position in the form of normally closed pneumatic cylinders.
The OV series mechanical pinch valves cover the entire scope of the low pressure range at an ideal price-performance ratio. The OV mechanical pinch valves also have an aluminium housing which makes assembly easier and saves on logistics costs.
The applications with higher operating pressures or requirements are ideally covered by the RV mechanical pinch valves.
The high number of variants also deserves mention. We probably have the greatest selection of materials and connection options.
There is no general answer for this. Strong vibrations can cause damage, particularly if the mechanical pinch valves are subjected to heavy stress. Our sales team is always available to advise you.
Yes, the mechanical pinch valves can be started up in any interim position, ideally with the aid of a pneumatic position regulator or an electrical actuator with control function.
Predefined interim positions can also be approached and set by proximity switches.
A positioning pin is attached to the OV manaual and control pinch valves up to nominal width DN50. This can also be installed at greater nominal widths on request.
Every mechanical pinch valve has certain advantages and performance limits which must be determined on the basis of the local circumstances. Our sales department will be happy to advise you.
A safe specification is -10°C. We know from experience, however, that the mechanical pinch valves also function flawlessly at lower temperatures.
The mechanical pinch valves can also be used at a slight vacuum pressure of up to 100-150mbar.
Please contact our sales team for applications at higher vacuum pressures and we will be happy to advise you.
Manually activated pinch valves are preferably used where automation is unnecessary due to infrequent activation. The self-locking spindle provides an additional benefit by ensuring that preset interim positions are not changed by media pressure fluctuations.
Air pressure can also be applied to the spring-loaded side of the cylinder to dampen the movement.
Yes, this can generally be assumed. Exceptions would be conceivable if the connection to pinch bars were interrupted, for example if the sleeves are overstressed and the opening tabs tear off.
The series OV mechanical pinch valves can be used at operating pressures up to 5 bars depending on their nominal width.
The series RV mechanical pinch valves are available in the following pressure classes for operating pressures of 6bar, 10 bar, 16bar, 25 bar and 40 bar.
AKO offers suitable accessory variants for both the pneumatic and electrical drives which can be used to perform the most diverse control tasks via a 4...20mA input current signal.
With position control, an input current signal is used to stabilise a percentage degree of opening of a fitting and to keep it constant even during media pressure fluctuations.
When an electrical motor drive is used, the self-locking spindle for this control variant prevents any load change.
With flow control, a higher-level flow measurement is used to adjust the input signal to the respective changes for the purpose of stabilising a desired flow rate. The drive is therefore exposed to load change cycles and must be designed accordingly.
Aluminium can be selected for the OV series mechanical pinch valves. Grey cast iron, steel or stainless steel can be selected for the RV series mechanical pinch valves.
Natural rubber, EPDM, EPDM for foodstuffs, neoprene or nitrile can be selected for the OV series mechanical pinch valves.
Natural rubber, natural rubber for foodstuffs, EPDM, EPDM for foodstuffs, nitrile, butyl or Viton can be selected for the RV series mechanical pinch valves.
Powdered coatings are used in accordance with the typical industry standard. The OV pinch valves are standardly painted in orange RAL 2009 and the RV pinch valves in RAL 5002. No special data sheets exist for the coatings.
Yes, the sleeves for the mechanical pinch valves can all be replaced on location without special tools.
For this purpose, we provide installation instructions and videos for all pinch valve types under the website heading "Downloads".
Since solely the elastomer/rubber sleeve of the manual and control pinch valves structurally comes into contact with the product in the product flow, it is the only component considered as an actual spare/wear part.
Corresponding installation manuals in 12 languages and maintenance/repair instructions on our website are available to you as ideal assistance for replacing the elastomer/rubber sleeve. They explain in detail how to replace the elastomer/rubber sleeves.
Click on Videos for Mechanical Pinch Valves to watch the videos right now.