Satish Lele satish.lele@gmail.com

These should be as simple as conditions allow. Stock items are used wherever possible, especially for piping held from above. To support piping from below, supports are usually made to suit from plates, pipes and pieces of structural steel. Following hardware is used to create supports.

1. Rest Support : The weight of the piping is usually carried on supports made from structural steel, or steel and concrete.

2. Hanger Support : It is a device which suspends piping (usually a single line) from structural steel, concrete or wood. These are generally adjustable for height.

3. Anchor Support : A rigid support which prevents transmission of movement (thermal, vibratory etc.) along piping. Construction may be from steel plate, brackets, flanges, rods, etc. Attachment of anchors to pipe should preferably encircle the pipe and be welded all around as this gives better distribution of stress in the pipe wall.

4. Tie Support : It is an arrangement of one or more rods, bars etc. to restrain movement of piping.

5. Dummy Leg Support : In this an extension piece (of pipe or rolled steel section) is welded to an elbow in order to support the line. This part rests or anchors on some steel member.

6. Guide : This is a means of allowing a pipe to move along its length, but not sideways.

7. Shoe : It is a piece of metal attached to the underside of a pipe, which rests on supporting steel. It is primarily used to reduce wear from sliding for lines subject to movement. It permits insulation to be applied to pipe.

8. Saddle : It is a welded attachment for pipe requiring insulation, and subject to longitudinal or rolling movement (resulting from temperature changes other than climatic). Saddles may be used with guides.

9. Slide Plate : In this two slide plates of graphite, teflon or some special materials, fixed to steel plates, are fixed to the flat surface of the pipe support. These plates are faced for low friction able to withstand mechanical stress and temperature changes.

10. Constant Load Hanger : This device consists of a coil spring and lever mechanism in a housing. Movement of the piping, within limits, will not change the spring force, holding up the piping; thus no additional force will be introduced to the piping system.

11. Variable Spring Hanger : This device consists of a coil spring in housing. The weight of the piping rests on the spring in compression. The spring permits limited amount of thermal movement. A variable spring hanger holding up a vertical line will reduce its lifting force as the line expands toward it. A variable spring support would increase its lifting force as the line expands towards it. Both place load on piping system, and where this is undesirable, a constant-load hanger can be used instead.

12. Hydraulic Dampner : These are also called as shock snubber or sway suppressor. One end of the unit is attached to the piping and the other to structural steel or concrete. The unit expands or contracts to absorb slow movement of piping, but is rigid to rapid movement.

13. Sway Brace : This is also called as sway arrestor. It is essentially a helical spring in a housing which is fitted between piping and a rigid structure. Its function is to buffer vibration and sway.