Page 54 - CPVC Fire Sprinkler Products Installation Instructions & Technical Handbook
P. 54

Vertical Restraint
When a sprinkler activates, a significant reactive force is exerted on the pipe, especially at system static pressures greater than 100 psi (6,9 bar). The reactive force will cause the pipe to lift vertically if it is not properly secured, especially if the sprinkler drop is from a small diameter pipe.
When a sprinkler drop is 3/4 in. (DN19) to 1 1/4 in. (DN32) pipe, the closest hanger should brace the pipe against vertical lift. A number of techniques can be used to brace the pipe
such as a standard band hanger
positioning the threaded support rod to 1/16 in. (1,6 mm) above the pipe or using a split ring or a wrap-around hanger for restraint.
Note: Threaded rod shall not come in contact with CPVC when installed. It is advisable to use lift restraint devices such as those produced by Tolco and Afcon that prevent the threaded rod from coming in contact with the CPVC pipe (as shown above).
Branch lines shall be braced at a distance from a tee or elbow to prevent lift of sprinklers as shown in Tables R or S.
The hangers used for vertical restraint can also serve as the hangers for “Hanger/Support Spacing.”

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