Control valve with detachable descrete curtain valve assembly

A valve having an adjustable flow coefficient, operable at very low torque and particularly useful for controlling flow of heat transfer fluids in heating, air conditioning and ventilation systems, which comprises a valve body having an inside surface, an inlet port comprised of an opening through the inside surface and enabling fluid flow into the valve body, an outlet port comprised of an opening through the inside surface and enabling fluid flow from the valve body, and a curtain valve closure, wherein the closure is adjustable to different flow coefficients to control fluid flow through the outlet port and is of a modular design including a flexible diaphragm attached to an insert positioned at least partially within the outlet port, and the insert has at least one dimension larger than a mating surface on the internal surface of the valve body to thereby secure the insert to the valve body without fasteners and to properly orient it within the outlet port.

A curtain valve according to any of the preceding claims wherein the insert is made of plastic.

A curtain valve according to any of the preceding claims wherein the insert is injection molded plastic.

A curtain valve according to any of the preceding claims wherein the insert is made of a plastic selected from the group consisting of Tefzel polymer, Delrin polymer, Teflon polymer or a combination of any of these.

A curtain valve according to any of the preceding claims wherein the curtain comprises a material selected from the group consisting of flexible plastic and silicone rubber.

A curtain valve comprising a valve body having an inside surface, an inlet port comprised of an opening through said inside surface of said valve body and enabling fluid flow into the valve body, an outlet port comprised of an opening through said inside surface of said valve body and enabling fluid flow from the valve body, and a curtain valve closure for adjustably controlling fluid flow through said outlet port and comprised of a flexible diaphragm extended between two locations, one of said two locations being a pivotally-moveable support and the other being a fixed support, wherein said curtain valve closure further comprises:

• a shoe adapted to press against the curtain and insert when the valve is closed, wherein said shoe is normally biased toward an unlocked position by spring means and is adapted to be operated against spring bias by an actuator.

An insert as described above having a width not any greater, including the neck, that permit installation.