Breathing valves of KDS-3000 and KDS-1500 types

Without a doubt, the tank equipment serves as the basis for the safe operation of the tank system. In turn, one of the brightest representatives of this type of equipment is undoubtedly "breathing" means, among which a special role seems to be assigned to the KDS type breathing valves.

The KDS breather valve is a rather complex mechanical device, the main purpose of which is determined by the function of adjusting the pressure of the vapor-gas-air medium formed as a result of evaporation of the product in the vertical tank in order to prevent its destruction. There are at least two types of breathing valves such as KDS-KDS-3000 and KDS-1500. The difference of these species lies in their technical and operational characteristics and throughput. For example, if the KDS-3000 breathing valves are intended, as a rule, for installation on vertical tanks of large capacity (from 10,000 cubic meters), then the type of KDS-1500 is used on smaller tanks (up to 10,000 cubic meters). Although, of course, in the end everything is determined in accordance with the technical and operational documentation developed by the project institute for the corresponding tank system. It should also be noted that the above types of valves, in turn, have their own internal gradation, differing in magnitude of the conditional pass of the steam-gas-air mixture (Dn). For KDS-3000 it is 250, 350 and 500 mm, while for KDS-1500 there are 150, 200, 250, 350 and 500 mm.

Despite a number of significant differences (including overall dimensions), the main components of the valves and the type of KDS-3000 and the type KDS-1500 are similar. Among them: a die-welded body (differs in design features, depending on the type, manufacturer and modification) on which there are saddles for the vacuum shutter, the vacuum closures themselves consisting of a vacuum plate and a fluoroplastic buckle fixed to the valve body and thereby Limits the displacement of the vacuum plate relative to the seat, a pressure plate that performs the function of releasing the vapor-gas-air mixture, a fluoroplastic film that does not freeze in cold weather, contacting Their surfaces, a lid providing protection from atmospheric precipitation, a fire barrier (made depending on the required diameter).

In addition, the principle of operation of these two types ("inhale-exhalation") is similar.

When an "inhalation" is carried out, a vacuum is created in the cavity of the breathing valves, equal in magnitude to the vacuum in the reservoir. When the calculated values of the vacuum (namely, the operating vacuum) are reached, the plates of the vacuum shutters are opened in the cavity of the breathing valve, combining the gas space of the reservoir with atmospheric air and thereby allowing the air mixture to pass into the reservoir. Accordingly, when the vacuum pressure is lowered to the calculated values, the shutter closes, sealing the reservoir.

At "exhalation", in the cavity of the body of the breathing valve an excess

Pressure, in its value equal to the pressure in the gas space of the reservoir. Thus, this pressure holds the plates of the vacuum gates against the respective seats and, at the same time, acts on the pressure plate, seeking to lift it. When the excess pressure in the body of the breathing valve increases by the amount of operation, the pressure dish opens, allowing the steam-gas-air mixture to escape from the reservoir to the atmosphere. Accordingly, after lowering the excess pressure below the calculated values, the plate returns to its original position (closing the shutter).

Installation of the breathing valves of these types is carried out by means of connection with the help of fasteners (hardware) to the mounting nozzle welded into the tank.

With proper care (observance of the operating and maintenance instructions), the average life of the breathing valves of the KDS-3000 and KDS-1500 types is at least 10 years.