Technical Booklet P Sanitary Appliances Unvented Hot Water Storage and Scalding·Page 15·2.15
Hydraulic resistance calculation for discharge pipes
Hydraulic resistance of discharge pipes must account for straight lengths, elbows and bends; copper pipes should be sized using Table 2.1 and the worked example method.
In calculating the hydraulic resistance of a discharge pipe the resistance of straight lengths, elbows and bends should be taken into account.
If a discharge pipe is of copper its size should be calculated using the values given in Table 2.1 and the method shown in the worked example.
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