ST-4 4" Submersible Bore Pumps
A dependable all-rounder for rural homes, stock water and medium-depth bores. The ST-4 stainless steel pump ends deliver strong pressure and flow, up to 24 m³/h and 322 m of head.
Why choose the ST-4
Stainless steel build
Polished 1.5 mm 304 stainless steel casing, cast stainless discharge head and motor adaptor, and a stainless hex shaft, coupling and strainer.
Handles some sand
Floating Noryl impellers cope with sand content up to 150 g/m³, so the pump keeps going in less-than-perfect bores.
Huge choice of models
Over 80 models across 11 flow ranges, from small household bores to 24 m³/h, so you get a pump that's matched to the job.
Fits standard 4" motors
NEMA-standard motor adaptor suits SUMOTO and SUMMAG motors and most other 4" submersible motors.
Drinking water safe
FDA-compliant glass-filled polycarbonate diffusers and a polyacetal bearing, suitable for household water supply.
Built-in non-return valve
A stainless steel non-return valve is built into the pump, holding the water in the rising main when the pump stops.
Choose your motor and controller
An ST-4 pump end pairs with a SUMOTO rewindable motor for a proven, economical bore pump, or with a high-efficiency Nastec SUMMAG motor for lower running costs.
Add a Nastec PILOT to protect a fixed speed pump, or a MIDA or VASCO drive for constant pressure and soft starts. We'll help you put the right combination together.
ST-4 ranges
| Range | Max flow (m³/h) | Motor sizes (kW) | Models | Outlet |
|---|---|---|---|---|
| ST-05 | 1.5 | 0.37 to 2.2 | 6 | 1¼" |
| ST-07 | 2.4 | 0.37 to 1.5 | 6 | 1¼" |
| ST-10 | 3.0 | 0.37 to 3 | 9 | 1¼" |
| ST-13 | 4.2 | 0.37 to 3 | 7 | 1¼" |
| ST-18 | 6.0 | 0.37 to 4 | 9 | 1¼" |
| ST-25 | 6.0 | 0.37 to 4 | 9 | 1½" |
| ST-35 | 8.4 | 0.75 to 5.5 | 8 | 2" |
| ST-40 | 12.0 | 0.75 to 7.5 | 9 | 2" |
| ST-55 | 14.4 | 1.1 to 5.5 | 7 | 2" |
| ST-60 | 15.6 | 1.5 to 7.5 | 7 | 2" |
| ST-80 | 24.0 | 2.2 to 7.5 | 6 | 2" |
Performance at 2850 rpm. The last two digits of each model number are the number of stages (impellers), so a higher number means more head. Ask us for full model tables and pump curves.
Enquire about ST-4 pumps
Tell us about your bore and how much water you need, and we'll come back to you with the right pump, motor and controller, plus a price.
Not sure of the numbers? Just give us what you know and we'll help with the rest.
Phone: 09 423 8061
Email: sales@watertechplus.co.nz
Monday to Friday, 8am to 4pm
