The main requirement of a valve with soft-pump function is to avoid turbulence during valve opening as this could negatively affect the process, e.g. through particle activation. In addition, rapid pressure changes as a result of high differential pressure during valve opening could cause sudden condensation effects, which could also adversely affect process parameters. The VLST FV Angle Valve with Soft-Pump Function avoids this.

The soft-pump function of the VLST is provided by an adjustable orifice in the closing plate. The adjustment wheel in the valve cover allows fine tuning of the soft pump effect. This ensures optimum calibration to the desired process parameters.

To enable simple and precise adjustment as well as easy resetting, the wheel is provided with flexible position markings. These facilitate the reproducibility of a setting as well as copying the setting to other valves that are to operate with the same setting.

Tested in thousands of demanding applications under various process conditions, the VLST series has proven its outstanding “soft” acting performance.

A positive side effect of the soft-pump function is that any pulse sound is reduced or avoided. This results in a quieter production/operation environment.

The VLST FV Angle Valve with Soft-Pump Function is based on a robust and reliable core design. The pneumatic actuator is single-acting, meaning that a closing spring closes the valve when pneumatic pressure is not applied.  The series is available in sizes DN 16 – 250mm either in aluminum or stainless steel.

Standard options for flange connections are ISO-KF and ISO-K, but customized flanges can also be integrated. An optical position indicator and an electrical position output signal are standard.