Proper support spacing is critical to ensure that deflection is kept to a minimum. Hangers used must have an adequate load bearing surface free of any rough or sharp edges that could damage the pipe during use. They must also not restrict linear movement of the system due to the effects of expansion and contraction; overtightening must be avoided.
| Pipe Size (in) |
73°F |
100°F |
120°F |
140°F |
160°F |
180°F |
Vertical Support
Vertical lines (risers) must be supported properly at intervals that will prevent excessive loading on the fitting at the lower end of the riser (or other stress concentration areas). Hangers and clamps suitable for this purpose include riser clamps or double bolt type clamps installed in such a manner that will allow for movement of the pipe due to thermal expansion and contraction (i.e. floating system). Clamps and hangers used must not compress, distort, cut, or abrade the piping. Clamps used must not exert compressive stresses on the pipe; the use of riser clamps that utilize compression to support the pipe weight are not recommended. If possible, the riser clamps should be located just below a fitting so that the shoulder of the fitting rests against the clamp to support the weight of the vertical column. Horizontal take-offs from the riser should be independently supported, and located as close to the riser clamp as possible. Offset configurations utilizing at least one change in direction should be used to tie horizontal runs into the riser in close proximity to the riser clamp. Offset configurations used between the riser tee and the wall entry will minimize stress on the horizontal connection should movement of the riser occur. The use of a single horizontal run from the riser tee through the wall should not be used on systems conveying hot water (i.e. use offsets at the riser connection).
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