How To Size Pipe for Solar Water Pumping

Use this chart to size the correct diameter pipe for your solar water pumping system.

Friction loss in plastic pipe with standard inside diameter (SIDR). Areas shaded in red should be selected with caution.

This chart applies only to: PVC pipe, Schedule 40 (160PSI) and to PE (polyethylene) pipe with SIDR designation (most common 100PSI black pipe).

Head loss in vertical feet per hundred feet of pipe or vertical meters per hundred meters of pipe

  Nominal Pipe Diameter (in) / Actual Inside Diameter (in)
FLOW RATE 1/2* 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4 5 6
GPM LPM 0.662 0.82 1.05 1.38 1.61 2.07 2.47 3.07 4.03 5.05 6.06
1 3.8 1.13 0.14 0.05 0.02              
2 7.6 4.16 0.35 0.14 0.05 0.02            
3 11 8.55 2.19 0.32 0.09 0.05            
4 15 14.8 3.70 0.76 0.19 0.07            
5 19 22.2 5.78 0.81 0.25 0.12 0.04          
6 23 31.0 7.85 1.00 0.35 0.18 0.07 0.02        
7 27   10.6 1.52 0.46 0.23 0.08 0.03        
8 30   13.4 1.94 0.58 0.30 0.09 0.05        
9 34   16.9 2.43 0.72 0.37 0.12 0.06        
10 36   20.3 2.93 0.88 0.46 0.16 0.07 0.02      
11 42   24.3 3.51 1.04 0.53 0.18 0.08 0.03      
12 46   28.6 4.11 1.22 0.65 0.21 0.09 0.04      
14 53     5.47 1.64 0.85 0.28 0.12 0.05      
16 61     7.02 2.10 1.09 0.37 0.14 0.06      
18 68     8.73 2.61 1.34 0.46 0.16 0.07      
20 76     10.6 3.16 1.64 0.55 0.21 0.08 0.02    
22 83     13.3 3.79 1.96 0.67 0.25 0.09 0.03    
24 91     14.9 4.44 2.31 0.79 0.30 0.11 0.04    
26 99       5.15 2.66 0.90 0.35 0.14 0.05    
28 106       5.91 3.05 1.04 0.42 0.16 0.05    
30 114       6.72 3.46 1.18 0.46 0.18 0.06    
35 133       8.94 4.62 1.57 0.62 0.23 0.07    
40 152       11.0 5.91 1.99 0.79 0.30 0.09 0.02  
45 171       14.2 7.37 2.49 0.97 0.37 0.12 0.04  
50 190       17.3 8.96 3.03 1.20 0.46 0.14 0.05  
55 208         10.7 3.60 1.43 0.55 0.16 0.06  
60 227         12.5 4.23 1.66 0.65 0.18 0.07 0.02
65 246         14.5 4.90 1.94 0.74 0.22 0.08 0.03
70 265         16.7 5.64 2.22 0.85 0.25 0.09 0.04
75 284         19.0 6.40 2.52 0.97 0.28 0.10 0.05
80 303           7.31 2.84 1.09 0.32 0.12 0.06
85 322           8.06 3.19 1.22 0.37 0.13 0.07
90 341           8.96 3.62 1.36 0.39 0.14 0.08
95 360           9.91 3.90 1.50 0.44 0.016 0.09
100 379           10.9 4.30 1.66 0.49 0.18 0.12
150 569           23.1 9.10 3.51 1.04 0.37 0.16
200 758             15.5 5.98 1.76 0.62 0.28
                         
NOTE: Values shaded in red are at velocities over 5ft per second and should be selected with caution.
* The 1/2″ data applies only to PE. PVC has a smaller internal diameter of 0.612