Diaphragm Pump 3GPM 11.36 L/min 3-Chamber Water Pump Pressure Switch

Water that dribbles out of a caravan tap turns rinsing sand off gear into a slow job, and a pump that hunts on and off through a shower is worse to live with. This three-chamber diaphragm unit holds 11.36 L/min at 50 PSI, so an outlet behaves much like one at home.

Three chambers smooth out the pulse

A single diaphragm only pushes on part of its stroke, which is why cheaper pumps deliver water in surges. Overlapping three chambers fills those gaps, and that is what turns 11.36 L/min (3.0 GPM) into something close to steady flow at 50 PSI. The difference shows at the tap: less shuddering when two outlets run together, and a shower that holds temperature instead of swinging hot and cold. A copper-wound motor and a noise-reducing base keep it quiet enough to run in a van after dark.

Starts and stops with the tap

The on-demand pressure switch does the thinking. Open an outlet and falling pressure starts the motor; shut it and rising pressure stops it, so it never labours against a closed valve. Cut-out adjusts between 40 and 100 PSI, wound down for tired plumbing or up for a long run to a rear shower. The supplier states the switch has been cycled beyond 200,000 times in testing.

Key features

• On-demand switching: no separate pump switch to remember after a wash-up.
• 40-100 PSI adjustment: one pump covers a low-pressure caravan line and a wash-down hose.
• 1/2" MNPT ports: the common fitting size, so a dead pump swaps straight out.
• Overheat and overload cut-outs: the motor protects itself if flow is blocked.

Specifications

• Flow rate: 11.36 L/min (3.0 GPM)
• Working pressure: 50 PSI
• Pressure switch range: 40-100 PSI, adjustable
• Inlet and outlet: 1/2" MNPT
• Motor: copper wound
• Markings stated by supplier: CE, RoHS
• Voltage and power draw: not published

Before you plumb it in

• The supplier names water as the fluid this pump is built for. Petrol, diesel and oil compatibility is not stated anywhere in the listing, so do not assume it.
• Supply voltage is not published. Confirm it with the seller before wiring the pump to a battery or an adapter.
• Fit a strainer upstream. Diaphragm pumps put up with a lot, but tank grit will chew the valve seats over time.

Suits caravans, campers, boats and food trailers, and the standard port size makes it a straight swap for a pump that has given up.