万搏网页版-万搏（中国）

FISHER™ VBL Volume Booster

The booster incorporates fixed deadband, soft seat construction, and an integral bypass restriction to eliminate positioner saturation problems that can occur with volume boosters that do not have these features. Adjustment of the integral bypass restriction is necessary for system stability. This adjustment does not affect the deadband of the volume booster, but does permit the control valve to respond to small input signal changes without sacrificing steady-state accuracy. It also allows the booster to deliver high volume output for fast stroking when large, rapid input signal changes occur. The volume booster is used to improve stroking speed.

Main Features

Fast Response — Booster delivers the volume needed for rapid actuator stroking when large input changes suddenly occur.
Adjustable Response — Integral bypass restriction tunes the booster response so that smooth actuator motion follows the slow signal changes
Efficient Operation — Soft seats provide tight shutoff to reduce unnecessary air consumption and eliminate saturation of positioner relays.
Maintains Accuracy — Booster permits high actuator stroking speeds upon demand without degrading the positioner steady-state accuracy.

Specifications

Input signal: Positioner output
Maximum input signal pressure: VBL-1 and VBL-3: 5.5 bar/80 psig; VBL-2 and VBL-4:10.3 bar/150 psig
Air Supply Pressure Range: When used in conjunction with a positioner or other pneumatic accessory, always pipe the positioner and booster with one common supply through a FISHER 67D, 67DR or 95H regulator (see Figure 3). A high‐capacity filter, such as the FISHER 262K, should be installed in the supply line to the regulator. Supply pressure also must not exceed the maximum pressure rating of the actuator.
Operating temperature range: -40 to 93°C/-40 to 200°F
Other Configurations: Contact us for more information.

Applications

The FISHER VBL volume booster is used in conjunction with a positioner on a throttling control valve to increase stroking speed.