By Stuart Allan, Surface To Surface Inc.
Hopper nozzle GPM is the flow your pump must deliver for an STS hopper mixer to shear properly. If you’re buying a 2″, 3″ or 4″ hopper system, here’s the flow and head your pump needs.
Short answer: at about 97 ft of head (about 42 psi, clean water, guns closed), the 2″ and 3″ STS hopper nozzles each need about 87 GPM and the 4″ needs about 184 GPM.
These are clean-water numbers with the guns closed, at about 42 psi on the gauge. That’s about 97 ft of head.
How much GPM does a 2″ hopper system need?
The M2-608 mix nozzle needs about 87 GPM at about 97 ft of head.
With the tank eductors open, we measured about 142 GPM through the whole system at 36 psi (83 ft).
How much GPM does a 3″ hopper system need?
The JR-3032-NE nozzle needs about 87 GPM at about 97 ft. Same as the 2″.
Measured system flow with the eductors open was about 193 GPM at 35 psi (81 ft).
How much GPM does a 4″ hopper system need?
The SR-75020-NE nozzle needs about 184 GPM at about 97 ft.
Measured system flow with the eductors open was about 339 GPM at 35+ psi (81 ft).
Pump requirements at a glance
| System | Mix nozzle | Nozzle flow at ~97 ft head | Measured system flow (eductors open) |
|---|---|---|---|
| 2″ | M2-608 | about 87 GPM | about 142 GPM at 36 psi (83 ft) |
| 3″ | JR-3032-NE | about 87 GPM | about 193 GPM at 35 psi (81 ft) |
| 4″ | SR-75020-NE | about 184 GPM | about 339 GPM at 35+ psi (81 ft) |
These are calculated clean-water figures. Our older flow tests were rough approximations. STS pump packages are sized to these numbers.
What should the gauge read?
On the job: with the guns closed, look for over 40 psi on the gauge. If you can’t get there, call us before you start swapping parts.
Frequently asked questions
How much GPM does a 2″ STS hopper system need?
The M2-608 mix nozzle needs about 87 GPM at about 97 ft of head. With the tank eductors open, measured system flow was about 142 GPM at 36 psi (83 ft).
How much GPM does a 3″ STS hopper system need?
The JR-3032-NE nozzle needs about 87 GPM at about 97 ft, the same as the 2″. Measured system flow with the eductors open was about 193 GPM at 35 psi (81 ft).
How much GPM does a 4″ STS hopper system need?
The SR-75020-NE nozzle needs about 184 GPM at about 97 ft. Measured system flow with the eductors open was about 339 GPM at 35+ psi (81 ft).
What pressure should my mud mixer gauge read?
With the guns closed, look for over 40 psi on the gauge. The figures in this guide are at about 42 psi, which is about 97 ft of head.
Are these numbers for water or mud?
They are calculated clean-water figures, with the guns closed. STS pump packages are sized to these numbers.
What if my pump can’t reach 40 psi?
Call STS at 800-567-0978 before you start swapping parts.
Questions or parts
Not sure your pump is big enough? Call us at 800-567-0978 or get a quote. For nozzles, gauges and other parts, see parts.
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