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Rod Hangers

Weight supports are provided to resist vertical pipe loads occurring in the gravity (downward) direction only. They are used on systems where deadweight is the only support load and not in locations where there could be uplift loads.

The most economical and common method of transmitting weight load to building steel is with rod hanger assemblies. Rods are strong in tension where their small radius of gyration makes them inadequate for any significant compression loading. Therefore, the rods must be located above the pipe to hang the pipe from the building steel. A number of manufactured ancillaries are needed for attaching. The loads will be calculated by the stress analysis software as soon as the design is laid out.

In order to save the designer time, each of the components is supplied by KEKSA in various sizes with pre-engineered load ratings. Whenever load-rated hardware is used, the analysis steps required in the design of the ancillary components are already pre-calculated thus saving expensive engineering time.

Aside from load capacities, the engineer must keep some additional deliberations in mind.

1. Horizontal thermal pipe movement must not develop an angle plus or minus 4 degrees off the vertical axis during operating conditions. Large thermal movement will lift the pipe, imposing additional stresses, and causing horizontal load that can cause the piping system to become unstable. If the 4-degree angle of the rod is not enough then a sliding support or a roller must be used.

2. Although rod hangers must be sized for normal peak loads there are times when they will be subject to additional loads such as downward seismic loads. Therefore rods having a capacity of 50% greater than design loads are often selected.

The recommended pipe attachments for weight supports on horizontal pipe runs are clamps or clevis hangers. Pre-engineered pipe clamps used with rods are the same as those which are used with spring hangers. The main considerations for selecting a clamp are the pipe diameter, the design temperature, and the required load capacity. Clamps may be either two-bolt or three-bolt arrangements. Two-bolt clamps can be used with bare pipe or very thin (less than 25mm) insulation). The three-bolt clamp is sufficiently long to permit the loading pin to be entirely clear of insulation

If your piping work uses engineered spring-type supports, then get in touch with us, we can help.