Electric Diaphragm Water Pump — reliable performance for liquid transfer, pressurization, and selfpriming applications Key benefits Consistent pressure and flow for demanding tasks: delivers up to 18.9 LPM 5.0 GPM and 55 PSI 3.88 bar to support multiple faucet outlets and pressurization needs. Selfpriming and automatic operation: selfpriming up to 3 m 9.84 ft and a builtin pressure switch for automatic start and stop without manual intervention. Durable materials and efficient motor: engineering plastic housing with copper and steel components plus a pure copper motor for long service life and stable operation. Safe and reliable controls: includes overload protection, overheating protection, grounding protection, and switch reflux to protect the pump and system. Main features Power and electrical: 110 V corded motor, 1.2 A running, 2.0 A maximum. Flow and lift: open flow 18.9 LPM 5.0 GPM, suction range 3 m 9.84 ft, maximum pressure 55 PSI 3.88 bar. Construction: engineering plastic body with copper and steel parts and a pure copper motor. Control type: pressure switch for automatic start/stop; pressure switch can be adjusted. Operating limits: maximum fluid temperature 65 C 149 F; noise level 55 to 60 dB. Connections and size: 1/2 inch hose adapter included; product dimensions 12.45 x 10.97 x 21.2 cm 4.9 x 4.32 x 8.35 in; package size 32 x 15 x 13.5 cm 12.6 x 5.91 x 5.31 in. Weight: net 2.8 kg 6.17 lbs, gross 3.06 kg 6.75 lbs. Available colors: black, white, blue. Assembly required. Package contents 1 Diaphragm water pump 1 Filter 2 Hose adapters Typical applications and scenarios RV and marine use: supply water for sinks, showers, and toilets on RVs, yachts, boats, and ships where selfpriming and automatic pressure control are required. Home pressurization and water supply: boost household water pressure for faucets and small pressurized systems or support solar pressurization and water purification equipment. Industrial and cleaning: vehicle and carpet cleaning, food and beverage handling, and water treatment equipment that require reliable transfer, spraying, or metering of liquids. Pressure switch adjustment 1. Remove the pressure switch cover. 2. Find the central hexagonal adjustment screw. 3. Turn clockwise to raise cutin pressure, counterclockwise to lower cutin pressure. Quick operation guide 1. Connect inlet and outlet pipes securely. The pump head is marked with an arrow indicating outlet direction. Tight connections prevent low pressure, poor suction, and leaks. 2. Install the supplied filter on the inlet. Recommended mesh density is at least 80 mesh. 3. Connect to a power source that matches the pump input: 110 V, rated current 1.2 A, max 2.0 A. 4. Turn on power and run the pump for 5 to 10 seconds to purge air from the pump and piping. When flow stabilizes, switch off, connect outlet fittings such as a faucet or spray gun, then resume use. 5. The pressure switch will stop the pump automatically when outlet is closed. Reopen the outlet to restart operation. Basic troubleshooting Pump receives power but does not run: open the pressure switch cover and temporarily connect the two internal switch wires to check whether the switch is the cause before assuming motor failure. Poor suction, low output, or low pressure: disassemble the pump head, inspect and clean debris from the pump cavity, valves, and diaphragm; tighten any loose pump head or motor bracket screws and reassemble. Pump unresponsive on first delivery: open the motor rear cover, check carbon brushes and springs, and install springs if they are not in place. Pump stalls after use: confirm the power supply can handle startup current. Starting current may be 3 to 5 times running current; ensure the supply and wiring are adequate. Compatibility and installation notes Hose adapter size: 1/2 inch. Use appropriate fittings and secure clamps where required. Suitable for a wide range of liquids that match the materials and maximum temperature limit of 65 C 149 F. Ensure proper grounding and wiring in accordance with local electrical codes. Assembly is required before first use. This diaphragm water pump combines selfpriming capability, automatic pressure control, and protective features to provide dependable water transfer and pressurization for RVs, marine use, home systems, and light industrial applications.