Solenoid Valve Applications: Vacuum

There are a few applications that our solenoid valves have been used, in a vacuum application setting.

One of the applications is in exposure units.

Solenoid valves in exposure units

Exposure units are machines designed for the printing and silk-screening fields and used for exposing pre-sensitised aluminum plates.
The machine works on images imprinted on films and reproduced on the plate.

An operator mans this machine by laying the plate on the carpet and, after closing the glass-holding frame, pushes the start button on the control panel. The exposure unit is equipped with a microprocessor to carry out the complete working schedule automatically: preheating of the lamp, pre-vacuum, vacuum, selection of the lamp power, main and secondary exposure, masking, switch-off of the lamp, re-establishment of the pressure. The solenoid valve and the vacuum pump are responsible for the cycle for creating vacuum inside the unit. When the pump is on the normally open solenoid valve is energized and closes the circuit keeping vacuum inside the unit. At the end of the exposure the pump stops and the solenoid valve is deenergized, opening the circuit to the outside and thus restoring the atmospheric pressure inside the unit. 

The type of solenoid valve that would be used in this application:

Here is a PDF file with a bit more detail about solenoid valves in this application:
Solenoid Valves in Exposure Units

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Solenoid valves in vacuum packers

Another Vacuum application that our solenoid valves have been used in is a packer.

A Vacuum packer is used to vacuum pack food in a different environment. This would be useful for supermarkets or butchers. 
Food is vacuum packed to prolong its preservation.

Foodstuffs inside plastic bags are blocked under the transparent bell. The bell is lowered and the vacuum cycle starts when a button is pressed. Air inside the chamber is sucked up by the pomp as indicated by arrows (fig.1); vacuum is generated and the plastic bag sticks to the product; an edge of the bag is then sealed. When this operation is over, the atmospheric pressure in the packing chamber is restored (fig.2) and the bell is opened. Two solenoid valves are employed in this application for the vacuum cycle. The former allows the pump to suck up air from the chamber and keep vacuum in the room when the sucking up operation is over. The latter restores the atmospheric pressure after the packaging has been sealed.

The type of solenoid valve that would be used in this application is:

Here is a PDF file with a bit more detail about solenoid valves in this application:
Solenoid Valves in Packers

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Solenoid valves in refrigerant loading systems

A refrigerant loading system is used to replace refrigerant gas in refrigeration systems. The unit will carry out a vacuum cycle followed by a loading cycle; it automatically checks vacuum signalling even for small leaks in the system, then quickly loads the refrigerant without the risk of a mistake.

The system is designed for three NC solenoid valves: (1) for loading the refrigerant, (2) on the vacuum line, (3) in the intake line of the vacuum pump (vacuum test). In the vacuum cycle solenoid valves 2 & 3 open and the pump takes in remnant gases from the air conditioner and lets them into a disposal container. Once the vacuum cycle is over, solenoid valves 2 & 3 close, the pump stops and solenoid valve 1 opens. Now the loading cycle begins and the refrigerant flows from the cylinder into the circuit of the air conditioner under the effect of vacuum. Thanks to the electronic scales the system will load the exact quantity of gas that had been previously taken.

The type of solenoid valve that would be used in this application is:

Here is a PDF file with a bit more detail about solenoid valves in this application:

Solenoid Valves in Refrigerant Loading Systems

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Solenoid valves in vacuum pumps

Vacuum pumps are devices that convey a defined volume of air from the suction to the exhaust areas, creating depression.

Electromechanical vacuum pumps usually operate on continuous duty and the requested level of vacuum is controlled by two solenoid valves positioned on the side of the vacuum. For example, in manufacturing semiconductors this system allows to stop the suction of air from the working chamber and divert it to a secondary way, thus keeping the requested vacuum conditions inside the chamber. In applications like this where the production of printed circuits requires a controlled atmosphere, inert gas is used. The gas enters the chamber per decompression. Therefore the system herewith described performs a safety function as well, preventing the gas from leaking outside. 

The types of solenoid valves that would be used in this application are:

Here is a PDF file with a bit more detail about solenoid valves in this application:

Solenoid Valves in Vacuum Pumps


You can view the V-Flow Solutions range of M&M solenoid valves here:

V-Flow Solutions: M&M Range


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