Page 185 - Tyco-Grooved-Fire-Protection-Products-Installation-Handbook

SYSTEM DESIGN 183 Angular Movement
System movement can be accommodated by providing for sufficient offset lengths. Temperature increases/decreases can further increase this movement.
When systems are anchored with partially deflected joints, the system can move to the fully deflected condition upon pressurization resulting in the “snaking” of the piping system. Light weight hangers may not be suitable to prevent the lateral motion.
Angular Deflection
Grinnell Flexible Couplings are capable of accommodating angular deflection.
The deflection published is a maximum value. For design purposes the maximum deflection should be reduced to account for field practices as shown:
Deflection
Nominal Pipe Size ANSI Inches
DN 1-1/4 - 3
32 - 80
4 - 24
100 - 600
Maximum Pipe Deflection Reduction
50% 25%