Dover Wayne Helix WM048523 - Pressure Test; Adjusting the By-pass Pressure

Vacuum test
Pressure
test
Pressure
adjustment
Figure 11.3: CPU Test Points
11.5.2 Pressure Test
To perform a pressure test, install a pressure gauge at the 1/4" NPT hole as shown in Fig 11.3.
Check to see if the relief valve pressure is in the 131-138 kPa (19 to 20 psi) in standard capacity
single and two product dual pumps, and 186-193 kPa (27 to 28 psi) in all high capacity and single
product dual pumps. The maximum field adjustment possible does not exceed 345 kPa (50 psi).
11.5.3 Adjusting the By-pass Pressure
1
Installed pressure gauge as explained in the paragraph above.
2
Remove the acorn nut (cap) which covers the adjustment screw and lock nut.
3
Turn the pump on, so that the motor and pumping unit are running, but leave the nozzle
closed.
4
Loosen the lock nut and turn the adjustment screw clockwise to increase the pressure and
counter-clockwise to lower the pressure.
5
Once the correct pressure is reached tighten down the lock nut and replace the acorn nut.
6
Remove pressure gauge.
188 WM048523 Rev 08 01/2019
11 Suction Pumps