Flap Exhaust Valves (Flap Stacks) Trapeze Hanger These are simple to install

These are simple to install and infinitely adjustable

Automatic gates utilize an electric solenoid to control compressed air as it is delivered to open and close pneumatic cylinders

Very heavy duty to withstand years of use

Exceeds temperature limit of most plastics and is an economical alternative to specialty fabric duct

not compatible with Heavy Gauge or airtight systems

Flap Exhaust Valves (Flap Stacks) Trapeze Hanger These are simple to installA resourceful after the fan product, flap exhaust valves, or stacks, are designed to open, like bird wings, with the airflow and close when the system is not exhausting. The lightweight and balanced blades produce minimal resistance to exhaust. The design of the housing and blades channel rainwater away from the opening and allow it to drain without intrusion into the ducting. Available in 4" to 32" diameter (contact for custom sizes). Also known as