Closers for exterior (and) interior doors shall be full rack and pinion type with cast aluminum alloy shell. Closers shall be concealed in a 4" (102 mm) high frame header. The slide track shall be concealed in the top rail of the door. Hydraulic fluid shall be non-gumming and non-freezing. (Closer shall be provided with a fireblocking door liner to permit installation in 20-minute wood fire door assemblies.) Closer shall have (four) (five) noncritical valves, hex-key operated, to independently regulate sweep speed, latch speed, backcheck cushioning (and backcheck positioning) (and delayed action closing). [Closers shall be sized units (4 only)]. [Closers shall have power adjustment to permit a 50% increase in power over the minimum closing force for any size.] [Closers shall have multi-sized adjustment for (interior doors)(exterior doors)].
Closer shall conform to Accessibility Code specifications. Degree of stop shall be field adjustable. Slide track shall have a built-in cushioning shock absorber mechanism. (Hold open mechanism shall be capable of release when holding function is not required. Hold open mechanism shall have an adjustable range 85°-110° of door opening and shall release with a manual pressure on the edge of the door in the direction of closer). Closer to be Norton® [Series 7900] [Series 7970] (with Norton® #790 Fire Block). 7970/7970DPS shall be supplied with Torx® lobular drive fasteners having a center security pin.
7970 DPS
Closer to have a door position switch to indicate "Door Open/Door Closed” condition.