Type A _is the basic unit of Variable Spring Hanger. It is designed for attachment to its supporting member by screwing a rod into a tapped hole in the top cap of the hanger the full depth of the top cap. The upper jam nut should then be locked, securing the hanger. Its upper hanger rod is anchored to existing structure, above the spring box housing. Upper hanger rod may be of different forms, viz, stud type and eye bolt type, depending on the formation of existing structure.
Adjustment of the hanger load is accomplished by turning the coupling on the lower hanger rod until the hanger picks up the load and the load indicator points to the desired position.
Type B _is furnished with a single lug for attachment to the building structure. The lug permits use of a clevis, welded beam attachment or a pair of angles for attachment where headroom is limited.
Type C is furnished with two lugs for attachment to the structure. These two lugs permit the use of an eye rod, or a single plate for attachment where headroom is limited.
Type D permits adjustment of the hanger from the top. This type has a piece of tubing which passes through a hole in the top cap. Type D is especially adapted for use where the hanger is set above the supporting beams and pipe is suspended below. The hanger rod is ended at the top of the spring box housing with a raised height enclose in a pipe.
Type E is designed to permit adjustment from either above or below the hanger, when it is installed upon the supporting member and pipe is suspended below. A coupling tapped right hand both ends is furnished. The Central Hanger Rod can be taken of the hole at the top of the spring box housing in assembled condition.
Type F This is a base mounted type Spring Support. This support is installed on any type of foundation base or on structure. The base plate of spring box housing is fixed with foundation bolts or by welding. The supported pipe rests on the top of the spring box housing in different manner. For example;
A) Some seating arrangement of pipe line is provided along with the supporting pipe which rests on the top of the spring box housing;
B) Some roller attachment can be provided on the top of the spring box housing, on which pipeline can rest and may, slide axially;
C) Some smooth sliding surface can be provided on the top of the spring box housing top plate on which the supported pipeline may be increased or decreased with a small magnitude.
The headroom of the F type support may be increased or decreased with the help of rotation of the load column pipe.
Type G is a complete trapeze assembly. The hanger consists of two standard spring units plus
a pair of back-to-back channels welded at each end to the hanger casing. The P dimension can be varied with the customers instructions. In sizing a Type G hanger, it must be remembered that each standard spring unit carries one-half of the total pipe load. Therefore, in using the hanger selection chart, use one-half of the total pipe load as the hot load. When the pipe line is designed so as not to be centered on the channel, one spring of the trapeze will carry a heavier load, the other a lighter load. Care should be taken in calculating the load of each hanger and in choosing the proper sized spring in such cases. The center-to-center rod dimension must be specified when ordering.