Plug

Sometimes called a poppet damper, this device has been developed in response to the need for a damper which gives virtually 100% shut off. Indeed, it can be made 'bubble tight' if required.

It consists of a circular plug which blocks a discrete opening similar to the action of a valve in an internal combustion engine. If the duct to be closed is large, several plugs are used working together, again similar to a multi- valve vehicle engine.

A pneumatically operated version is available where the gas stream enters from the bottom and exits horizontally to the right.

However, in-line versions are available.

It is also possible to operate the unit with a linear electric actuator or a lead screw type mechanism.

A feature of this device is that the seal is metal to metal. There are no soft seals to wear and be replaced. This also means that the device can be used on high temperature applications.

We would not normally recommend this type of damper for modulating duty.