Hangers
Rubber-in-shear hanger shall be ARH and ARHD with static deflection of .20 or .40 respectively. The molded neoprene element shall be housed within a steel housing.

Spring hangars shall be Airmaster type ST consisting of a spring as previously specified, in a box type metal frame. The hangers shall be complete with an acoustic rubber element and rubber insert sleeve.

Bases
Integral steel fan and motor bases shall be of structural steel construction and rigid enough to resist the bending stress of belt pull. Motor slide base shall be steel fabricated or cast iron as per requirement.

Inertia base forms shall have full depth perimeter structural channel with isolator supports welded to the steel channel sides. An adjustable motor slide rail shall be supplied for fan units requiring same. The inertia base shall clear the sub-base by a minimum of 1'/2. The concrete inertia base shall be 1'/2 times the weight of the supported equipment on basement grade, and 2 times weight of supported equipment on upper floors, unless stated otherwise. For extreme critical applications consult your A VC representative.

Mounts
Airmaster NSN pad type isolator consisting of '/2 thick neoprene rubber corrugated both surfaces shall be bonded to 1/. steel plate.

Rubber-in-shear mounts shall be Airmaster type AR or ARD. The units shall be of molded element design for .20 or .40 static deflection under imposed load. Airmaster type 368 SD with '/2 deflection shall be used on C rails where specified.

All housed spring mounts shall be complete with stable, colour coded springs, with levelling device and ribbed neoprene vibration under pad. For deflection less than 1 , type ASL cast aluminum type mountings shall be used with a minimum 2 O.D. spring.

Open type OS free standing, stable spring isolators shall be used for deflections greater than 1.25. Each spring unit shall be designed with a good ratio between the diameter and the working height to assure lateral stability. The unit isolator shall have top level adjustment and ribbed rubber pads on the bottom for sound deadening.

Type OST and KW spring isolators shall have type OS characteristics with the following features. The spring unit isolator shall have a built-in limit control device to restrain the upward travel when the weight is temporarily removed, and also provide safety stop for windy roof top locations. All unit isolators located outdoors must have hot-dipped galvanized housing and accessories; springs are to have two coats of an approved rust resistant paint to resist corrosion.