Gas PipingQuestion 266 of 360
When sizing gas piping, why does the code sometimes require adding equivalent lengths for fittings such as elbows and tees?
a.Because fittings add flow resistance, so their equivalent length increases the effective pipe length used in the tables
b.Because fittings reduce the total length
c.Because fittings have nothing to do with sizing
d.Because equivalent length only applies to water piping
Explanation
Elbows, tees, and valves add resistance to gas flow, and some sizing methods account for that by adding an equivalent length of straight pipe for each fitting. This increases the effective length used to select pipe size, guarding against excessive pressure drop. Simpler table methods may build in an allowance instead, so follow the specific method's rules.
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