The IVR model Butterfly dampers, offered by Intervalve are essentially seatless Butterfly valves intended for low pressure gas lines and air lines. The lightweight construction with the narrow wafer body enables easy fitment of these valves in ducts, manifolds and exhaust lines without additional support or strengthening of pipe lines.
IVR valves are primarily intended for low-pressure large volume gas / air flow control applications. The absence of seat substantially reduces the valve operating torque requirements and makes the valve very effective for flow control / regulation duties. IVR is an ideal choice for furnace air flow and combustion control applications.
Even though the body is designed for a maximum pressure of 2.5 bar the maximum shut off pressure is limited to 0.5 bar only. The disc flap is held in position by a stub shaft with an axial locking arrangement provided on the top shaft. The top shaft sealing is through stuffing box type gland sealing arrangement, which is field adjustable.