Accessories - Italbest Valve s.r.l.


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Valve actuators are selected according to several factors including torque, which is necessary for operational purposes, and the need to implement automatic operation.
Examples of different types of actuators include manual handwheel, manual lever, electrical motor pneumatic, solenoid, hydraulic piston, and self-actuated. All actuators, except for manual hand wheel and lever, can be activated automatically. The actuators are designed on the torque of the valves, the function for which it will be used or particular requests from the costumer.

Even if manual actuators cannot be activated automatically, they allow for the valve to be positioned in any location.  The most common type of mechanical actuator is the handwheel. This type includes handwheels fixed to the stem, hammer handwheels, and handwheels connected to the stem through gears. Handwheels fixed to the stem have the sole mechanical advantage of the wheel. When these valves are exposed to high operating temperatures, operational efficiency is hindered by mechanical seizure. The hammer hand wheel partially rotates freely and then strikes a lug on a secondary wheel. The secondary wheel is connected to the valve stem.

If additional mechanical advantage is required for a manually-operated valve, the valve bonnet is fitted with manually-operated gear heads. A special wrench or hand wheel connected to the pinion shaft allows for valve operation by only one person. Since several rounds of the pinion are necessary to produce one entire turn of the valve stem, the operating time of large valves is exceptionally long. The use of portable air motors connected to the pinion shaft reduces the valve operating time.

Electric motors permit manual, semi-automatic, and automatic operation of the valve. Motors are used mostly for open-close functions, although they are adaptable to have the valve positioned at any point. The motor is generally reversible, high speed, and connected through a gear train to reduce the motor speed and thereby increase the torque at the stem.

 Direction of motor rotation determines direction of disc motion. The electrical actuation can be semi-automatic when the motor is activated by a control system. A handwheel, which can be used with the gear train, is provided for manual operating valves. Limit switches are normally used to stop the motor automatically at full open and full closed valve positions. Limit switches operate either physically by position of the valve or by torque of the motor.

Pneumatic actuators are provided for automatic or semiautomatic valve operations. These actuators translate an air signal into valve stem motion by air pressure acting on a diaphragm or by a piston connected to the stem. Pneumatic actuators are used for open-close position where fast action is required. Duplex actuators have air supplied to both sides of the diaphragm. The differential pressure across the diaphragm positions the valve stem. Automatic operation is provided when the air signals are automatically controlled by circuitry. Semi-automatic operation is provided by manual switches present in the circuitry.

Hydraulic actuators provide for semi-automatic or automatic positioning of the valve, similar to pneumatic actuators. These actuators use a piston to convert a signal pressure into valve stem motion. Hydraulic fluids go inside one side of the piston while on the other side they are drained. Water or oil are used as hydraulic fluid. Manual valves can be used for controlling the hydraulic fluid, too so that semi-automatic operation is provided.

Solenoid actuators have a magnetic slug connected to the valve stem. The force to place the valve comes from the magnetic attraction between the slug on the valve stem and the coil of the electromagnet in the valve actuator.

Control Panel

Control panels provide a reliable way to control both pneumatic and hydraulic ball, butterfly and plug valves. Our control panels use the highest quality components for extensive usage, they also provide an adjustable operating time that goes beyond the critical surge period.
The electrical panels provide remote monitoring of the valve, pump operation and alarm condition.
Our control panels are designed for air, oil, water usage. They can be provided with junction boxes as required by the client and with an optional manually controlled valve to be used during power outages.