Pressure Control Valve
There are two types of VCP valves, ø 273 and ø 375, with flanges and body in carbon steel, powder coated. The valve is made up of a valve disc, weather protection cover, stub pipe under valve for connection to the silo and an inspection hatch. It is necessary to use the lower ring to trace the hole to be drilled on the top of the silo and once the drilling has been performed, the ring must be welded to the silo in a perfectly horizontal way. It is necessary to check and remove the dust in the area surrounding the inspection hatch on a weekly basis and check the perfect connection on a monthly basis.
An important element is the interface flange: placed between the valve and the ring welded to the silo, it provides the possibility to vary the valve diameter without additional operations. The pressure control valve is used in all plants where it is necessary to control any excess pressures or negative pressures that are created inside containers, thus avoiding breakages or deformations.
As for its operation, the VCP valve is not controlled by external devices. It starts up automatically whenever there is a pressure imbalance inside the silo due to filling or emptying the silo by means of any system. The environmental temperature within which the valve can work varies between -20 ° / + 40 ° C, maximum temperature of dusts is + 70 ° C. The standard pressure is 0.5 bar, but there are two possible alternatives: 0.3 and 0.8 bar. With a different kit it is possible to change the valve springs. A ring is provided to be welded to the silo, where the valve will then be bolted. Machine temperature level: the VCP valve in its normal operation does not give rise to hot surfaces. Noise level: the only source of noise present on the valve is due to the air that passes through during operation. The VCP valve is usually installed on the top of the silos.
Permitted use: these machines are specifically designed for use with powders and granules.
Due to the conformation of the VCP valve and the type of working, each time the pressure value for which the valve has been calibrated is exceeded, it will open releasing an air-dust mixture (in the form of a dust cloud ) to the outside, only during the activation phase due to overpressure. The valve only has the function of safeguarding containers, filters and other equipment from overpressures or negative pressure outside the tolerance limit. The VCP valve in all its sizes can be equipped with an inductive signalling system. This device is used for signalling the opening of the valve in overpressure or negative pressure to the prefixed calibration value.
The first valve start-up test is done without material; if everything works perfectly then it is possible to add material and proceed normally. There are no switch off procedures and periodic inspections are required. Before any kind of operation it is necessary to set the machine in safety status. At the end of the valve work on the container, clean the inside of the valve and then the surrounding area.