CALCULATE TOTAL DYNAMIC HEAD

Sump/Sewage/Grinder TDH Calculation Worksheet

Use the tables below to calculate Total Dynamic Head (in Feet) required.

  1. Use steps 1-3 and the following chart to calculate TDH from tables A & B below.
  2. Enter the TDH, in Feet, in the box under “Design Flow Rate” on the Pump Design Guide.

Table A:
Friction Losses through Plastic Fittings in
terms of Equivalent Lengths of Plastic Pipe
 
Type
of Fitting		 1-1/4″ 1-1/2″ 2″ 2-1/2
“		 3″ 4″
90
deg. Std Elbow		 7.0 8.0 9.0 10.0 12.0 14.0
45
deg. Std Elbow		 3.0 3.0 4.0 4.0 6.0 8.0
Std.
Tee		 7.0 9.0 11.0 14.0 17.0 22.0
Check
Valve		 11.0 13.0 17.0 21.0 26.0 33.0
Union 1.0 1.0 2.0 3.0 4.0 5.0
Gate
Valve		 0.9 1.1 1.4 1.7 2.0 23.0
Table B:
Friction Loss per 100 Feet of Plastic Pipe
 

Pipe
Size (in.)

Flow Rate (GPM)

 1″ 1-1/4″ 1-1/2″ 2″ 2-1/2
“		 3″ 4″

2

 0.3            

3

 0.6            

4

 1.0 0.3          

5

 1.5 0.4 0.2        

6

 2.1 0.6 0.3        
7 2.9 0.8 0.4        
8 3.6 1.0 0.5        
9 4.6 1.2 0.6        
10 5.5 1.5 0.7 0.2      
               
12   2.1 1.1 0.3      
14   2.7 1.3 0.4      
16   3.5 1.7 0.5 0.2    
18   4.4 2.1 0.6 0.3    
20   5.2 2.5 0.9 0.3    
               
25     3.8 1.3 0.5    
30     5.2 1.8 0.6    
               
35       2.4 0.8    
40       3.1 1.0 0.4  
               
45       3.8 1.3 0.6  
50       4.7 1.6 0.7  
               
60         2.2 0.9 0.2
               
70         2.9 1.2 0.3
               
80         3.7 1.5 0.4
               
90         4.6 1.9 0.5
               
100           2.3 0.6

For
flows over 100 GPM, please contact STH.