Description:

A Type JVBR- 90 Series Volume Booster (Figure 1) is used in conjunction with a positioner on a throttling control valve to increase stroking speed of Pneumatic Control Valve. It is designed to use a pneumatic signal to produce an output pressure which has high flow capacity. The unit is most useful for systems requiring the conversion of a low flow control signal to the higher flow requirements of an operating system. Using an independent supply pressure for greater volume, the JVBR series gives upto 50 SCFM flow to a final control element such as a valve actuator.

The Booster incorporates soft seat construction, and an integral bypass restriction to adjust positioner speed so as to eliminate hunting of control valve and to increase the speed of the control valve system. Adjustment of the integral bypass restriction is necessary for system stability.

The Volume Booster, is used in conjunction with a positioner to improve stroking speed. If the volume booster is to be used only with an actuator for on-off control, the integral bypass restriction on the booster must be closed.

Features:

FAST RESPONSE:
Booster delivers the volume needed for rapid actuator stroking When large output changes suddenly occur.

ADJUSTABLE RESPONSE :
Integral bypass restriction tunes the booster response so that Smooth actuator motion follows the slow signal takes place.

EFFICIENT OPERATION :
Soft seats provide shutoff to reduce unnecessary air consumption and eliminate saturation of positioner relays.

MAINTAINS ACCURACY :
Booster permits high actuator stroking speeds upon demand Without reducing the positioner steady-state accuracy.

HIGH FLOW CAPACITY :
Allows flows upto 50 SCFM

- STABLE OUTPUT :
Venturi aspirator maintains output pressure under varying flow Condition.

HIGH EXHAUST CAPACITY :
Large relief valve provided 15 SCFM Flow capacity

Applications:

The Type JVBR is used extensively for increased flow capacity, or remote pressure control applications. This includes control valve actuators, I/P volume boosting, cylinder actuation, clutch and brake control, and gas flow control.

Operations:

PRINCIPLE OF OPERATION:

When pressure is introduced through the signal port of the JVBR-090, a downward force on the upper diaphragm area is created. This force is balanced by the output pressure acting against the lower control diaphragm area. The ratio of signal pressure to output pressure is determined by the ratio of the effective areas of the upper and lower diaphragms. If signal pressure is increased above the output pressure there is a net downward force on the diaphragm assembly causing the supply valve to open. Output pressure increases until equilibrium is achieved. When signal pressure is decreased below the output pressure, the diaphragm assembly rises, allowing output air to exhaust through the exhaust port on the side of the relay.