Adequate pipe support is essential for a durable and properly functioning piping system. Without the support it needs, piping systems incur stress and sag that lead to degradation and break down.
There are a number of factors that go into calculating the amount of support each system needs. There are all kinds of formulas and techniques used to determine the amount of support required. You’ll find that your support needs vary from system to system based on configuration, pipe size, load, and temperature.
There are also other things to keep in mind when planning your support. Valves and other points of extra load should be supported separately from your pipe spacing. You should also consider how much your pipe will expand or contract in different atmospheric conditions. Apply any clamps or supports with this fluctuation in mind.
There are a number of helpful reference guides designed to assist you in determining the proper spacing for your PVC pipe system. These guides are only a general estimate, and they are usually based on a several assumptions. The chart below, for example, assumes you are using un-insulated pipe to carry fluids of a specific gravity no greater than 1.0. This chart should only be used as a general guide.
As we’ve pointed out, there are various factors that contribute to support requirements that you will need to take into account for each system you create. If in doubt, more than enough support is always better than inadequate support.
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PVC PIPE SUPPORT SPACING (ft.) |
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| PIPE SIZE (in.) | SCHEDULE 40 TEMPERATURE (°F) |
SCHEDULE 80 TEMPERATURE (°F) |
SCHEDULE 120 TEMPERATURE (°F) |
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| 60 | 80 | 100 | 120 | 140 | 60 | 80 | 100 | 120 | 140 | 60 | 80 | 100 | 120 | 140 | |
| 1/4 | 4 | 3 1/2 | 3 1/2 | 2 | 2 | 4 | 4 | 3 1/2 | 2 1/2 | 2 | |||||
| 3/8 | 4 | 4 | 3 1/2 | 2 1/2 | 2 | 4 1/2 | 4 1/2 | 4 | 2 1/2 | 2 1/2 | |||||
| 1/2 | 4 1/2 | 4 1/2 | 4 | 2 1/2 | 2 1/2 | 5 | 4 1/2 | 4 1/2 | 3 | 2 1/2 | 5 | 5 | 4 1/2 | 3 | 2 1/2 |
| 3/4 | 5 | 41/2 | 4 | 2 1/2 | 2 1/2 | 5 1/2 | 5 | 4 1/2 | 3 | 2 1/2 | 5 1/2 | 5 | 4 1/2 | 3 | 3 |
| 1 | 5 1/2 | 5 | 4 1/2 | 3 | 2 1/2 | 6 | 5 1/2 | 5 | 3 1/2 | 3 | 6 | 5 1/2 | 5 | 3 1/2 | 3 |
| 1 1/4 | 5 1/2 | 5 1/2 | 5 | 3 | 3 | 6 | 6 | 5 1/2 | 3 1/2 | 3 | 6 1/2 | 6 | 5 1/2 | 3 1/2 | 3 1/2 |
| 1 1/2 | 6 | 5 1/2 | 5 | 3 1/2 | 3 | 6 1/2 | 6 | 5 1/2 | 3 1/2 | 3 1/2 | 6 1/2 | 6 1/2 | 6 | 4 | 3 1/2 |
| 2 | 6 | 5 1/2 | 5 | 3 1/2 | 3 | 7 | 6 1/2 | 6 | 4 | 3 1/2 | 7 1/2 | 7 | 6 1/2 | 4 | 3 1/2 |
| 2 1/2 | 7 | 6 1/2 | 6 | 4 | 3 1/2 | 7 1/2 | 7 1/2 | 6 1/2 | 4 1/2 | 4 | 8 | 7 1/2 | 7 | 741/2 | 4 |
| 3 | 7 | 7 | 6 | 4 | 3 1/2 | 8 | 7 1/2 | 7 | 4 1/2 | 4 | 8 1/2 | 8 | 7 1/2 | 5 | 4 1/2 |
| 3 1/2 | 7 1/2 | 7 | 6 1/2 | 4 | 4 | 8 1/2 | 8 | 7 1/2 | 5 | 4 1/2 | 9 | 8 1/2 | 7 1/2 | 5 | 4 1/2 |
| 4 | 7 1/2 | 7 | 6 1/2 | 4 1/2 | 4 | 9 | 8 1/2 | 7 1/2 | 5 | 4 1/2 | 9 1/2 | 9 | 8 1/2 | 5 1/2 | 5 |
| 5 | 8 | 7 1/2 | 7 | 4 1/2 | 4 | 9 1/2 | 9 | 8 | 5 1/2 | 5 | 10 1/2 | 10 | 9 | 6 | 5 1/2 |
| 6 | 8 1/2 | 8 | 7 1/2 | 5 | 4 1/2 | 10 | 9 1/2 | 9 | 6 | 5 | 11 1/2 | 10 1/2 | 9 1/2 | 6 1/2 | 6 |
| 8 | 9 | 8 1/2 | 8 | 5 | 4 1/2 | 11 | 10 1/2 | 9 1/2 | 6 1/2 | 5 1/2 | |||||
| 10 | 10 | 9 | 8 1/2 | 5 1/2 | 5 | 12 | 11 | 10 | 7 | 6 | |||||
| 12 | 11 1/2 | 10 1/2 | 9 1/2 | 6 1/2 | 5 1/2 | 13 | 12 | 10 1/2 | 7 1/2 | 6 1/2 | |||||
| 14 | 12 | 11 | 10 | 7 | 6 | 13 1/2 | 13 | 11 | 8 | 7 | |||||
| 16 | 12 1/2 | 11 1/2 | 10 1/2 | 7 1/2 | 6 1/2 | 14 | 13 1/2 | 11 1/2 | 8 1/2 | 7 1/2 | |||||
| 18 | 13 | 12 | 11 | 8 | 7 | 14 1/2 | 14 | 12 | 11 | 9 | |||||
| 20 | 14 | 12 1/2 | 11 1/2 | 10 | 8 1/2 | 15 1/2 | 14 1/2 | 12 1/2 | 11 1/2 | 9 1/2 | |||||
| 24 | 15 | 13 | 12 1/2 | 11 | 9 1/2 | 17 | 15 | 14 | 12 1/2 | 10 1/2 | |||||
| This chart is meant only as a general reference guide. Additional calculations and considerations should be taken into account when determining pipe support. | |||||||||||||||
Keep in mind, liquids of a higher specific gravity will require greater support. Usually this means making supports closer together. All of these measurements assume your piping system will be horizontal. Spacing for vertical systems should usually be about two times the intervals in the table above.
If you are working on an inspected job, you will also need to be aware of any specific code requirements for pipe support in your area. Supports should at the very least be compliant with all codes and regulations you will face. Have more advice or suggestions for pipe support? We'd love to hear your comments.
