Product Features
The Perko consists of a long cylinder and plate fixed to an anchor plate by a chain. The cylinder is mortised into the inner edge of the door and held in position by the cylinder plate. The anchor plate is fitted to the door frame. When the door is opened the spring is compressed. On release the spring extends and automatically pulls the door closed. Speed of closure is controlled by spring tension which may be adjusted at any time. There is no hydraulic control with this type of closer.
Please note that this closer is not suitable for doors fitted with rising butt hinges, parliament or projecting hinges. They are suitable for use on latched fire-resisting doors subject to approval by the appropriate fire authority, however they are not generally recommended for this purpose. Fitting smoke seals/draught excluders or lack of ventilation in a small room can affect the closer performance.