esp(Effective System Protection):
maximum system output with
minimal pump starts
The ESP sizing procedure covers modern residential water-use habits, increased off-peak
demands and the general increase in water use that have occurred over the past twenty-five years.
ESP sizing is designed to reduce pump wear and tear, and reduce energy consumption by keeping
pump starts to a minimum.
Choose the amount of protection you need.
ESP I: Tank selection is based on approximately one minute minimum pump running time.
This is recommended for pumps up to 3/4 H.P.
ESP II: Tank selection is based on approximately two minute minimum pump running time.
This is recommended for 3/4 H.P. or larger pumps.
ESP Sizing Table
OPERATING PRESSURE - PSIG
PUMP DISCHARGE ESP I ESP II
RATE GPM (Approx.) 20/40 30/50 40/60 20/40 30/50 40/60
5 WX-202 WX-202 WX-202 WX-202XL WX-205 WX-205
7 WX-202 WX-202 WX-202XL WX-205 WX-250 WX-251
10 WX-202XL WX-205 WX-205 WX-251 WX-251 WX-255
12 WX-205 WX-250 WX-250 WX-251 WX-255 WX-255
15 WX-250 WX-250 WX-251 WX-255 WX-302 WX-350
20 WX-251 WX-251 WX-255 WX-350 WX-350 (2) WX-255
25 WX-251 WX-255 WX-302 (2) WX-251 (2) WX-255 (2) WX-302
30 WX-255 WX-302 WX-350 (2) WX-255 (2) WX-302 (2) WX-350
35 WX-302 WX-350 WX-350 (2) WX-302 (2) WX-350 (2) WX-350
40 WX-350 WX-350 (2) WX-255 (2) WX-350 (2) WX-350 (3) WX-302