The Holyoake HCD-150 is a precisely made volume and pressure control device with extremely low leakage (in the range of 0.003 m3/s at 100 Pa) when closed. It offers great structural strength and very low resistance when open. Suitable for smoke applications up to 200˚C.

The Holyoake HCD-75 is a precisely made volume and pressure control device with extremely low leakage (in the range of 0.003 m3/s at 100Pa) when closed. It offers increased control of an air stream in a size between an OBD3 and the HCD-150. Like the HCD-150, the HCD-75 offers low resistance when open.

The Holyoake HCD-225 is a heavy duty control damper which has been designed for applications that may exceed the design parameters of the HCD-150 control damper. This could typically be in areas of high turbulence or extremely high differential pressure or velocity where severe buffeting could preclude the use of a standard control damper. The HCD-225 is a specialised item and consultation with the factory prior to ordering would be recommended to ensure that the best solution for each application can be found.

The Holyoake HBD-155 is a control damper designed for the balancing of airflow. The HBD-155 can be used for motorised applications, however it is not designed to be a low leakage shut off damper. The frame of the

HBD-155 damper has been designed to mate with duct flanging systems for easy installation.

The Holyoake Model BDE is a medium duty pressure relief damper constructed of extruded aluminium. It operates at low opening pressure differential and with minimal leakage when closed against reverse flow.