Template Wet Riser Calculation

PROJECT : ??? WET RISER SYSTEM (???) The pumps selected are based on the following Fire Brigade's requirements : a) Where there are floors higher than 30 m above fire service access level, wet fire mains should be installed owing to the pressures required to provide adequate firefighting water supplies at the landing valves at upper floors & to ensure the water is immediately available at all floor levels. b) Each pump should be capable of providing a flow of water of at least 1500 l/min in the fire main, sufficient to serve lines of hose from three separate landing valves simultaneously. A minimum running pressure of 4 bar & maximum running pressure of 7 bar should be maintained at each landing valve when fully opened. c) The riser pipe diameter should be 150 mm galvanised iron to B.S. 1387 (Heavy gauge) or Class C. Data : (i) Static head (from pump level to highest outlet on the wet riser main) (ii) Head required at highest wet riser outlet (iii) Hazen Williams Formula Pipe length Volumetric flow rate Pipe roughness coefficient, C Pipe diameter Head loss per 100 m pipe length Head loss per 1 meter pipe length

Value 100 55 100 1500 0.025 120 0.15 1.699432 0.016994

Calculation : 1. Total Length and equivalent length of delivery pipe. (from pump outlet to highest outlet) Type (0.15 m dia.) Equivalent Length Total Length (m) Qty Total Pipe Length 1 200 200 90 Std Elbow 1 2 2 Gate Valve 1 1.1 1.1 Check Valve 1 7.2 7.2 Overall Total Length (A) 210.3 2. Total Length and equivalent length of suction pipe. (from tank suction to pump inlet) Type (0.15 m dia.) Equivalent Length Total Length (m) Qty Total Pipe Length 1 10 10 90 Std Elbow 1 2 2 Gate Valve 1 1.1 1.1 Strainer 1 33.5 33.5 Overall Total Length (B) 46.6

3. Friction head Total length of delivery & suction pipe (A) + (B) Friction head through pipe works

Value 256.9 4.36584

4. Head required Static head (from pump level to highest outlet on the wet riser main) Head required at highest wet riser outlet Friction head Total Head Required SELECTED PUMP PERFORMANCE

Value 100 55 4.36584 159.3658 160 530

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