Plunger valve is controlled by its own medium

VAG brings the control and regulating valve type Riko onto the market, which has all the advantages of a needle valve with those of a self-controlled valve drive connects. So far one could Needle valve cannot be used in areas where no Electricity or auxiliary power was available. The automatic and from Own medium The actuator operated by the pipeline with an integrated safety function can also be used for needle valves.

This is what connects the VAG Riko all the advantages of a needle valve such as functional reliability, control characteristics or cavitation behavior, with the advantages of a drive controlled by its own medium. Plunger valves are straight-through control fittings, with an annular flow cross-section in every position.

Inside the housing, the open piston is opened by a crankshaft moved axially towards the sealing seat of the valve in the direction of flow. The control valve creates different pressure losses in line systems through a continuous constriction towards the seat in order to change the flow rate depending on the travel.

Differential pressure overcomes flow forces in the needle valve

The main components of the drive form the Control circuit with its pilot valve and a proven drop weight drive. The energy required for opening comes from the existing pre-pressure, which is always greater than the back pressure when a system is in operation. This differential pressure across the valve is used to overcome the forces of the falling weight and the dynamic flow forces in the valve.

For the Closing movement the falling weight pushes the water on the piston side (internal medium) back into the medium flow of the pipeline via a piston. In addition, the drop weight forces are dimensioned in such a way that the plunger valve safely moves into the closed position in the event of a pressure equalization.

Externally controlled needle valve

Product animation for the needle valve as externally controlled control valve: For water with a ring cross-section, it is used for stepless control of high flow rates and pressure differences.