Positive Displacement 3 Chamber Diaphragm Pump- 100 PSI, 230 Volt Upgraded from 8090-902-248 (no internal bypass) see below OEM Associations: Shurflo 8090-802-289 MODEL NUMBER: 8090-902-278 High Pressure Demand Pump w/ Bypass 1.4 GPM open flow, Viton® valves, Santoprene®diaphragm, 100 PSI Demand Switch, w/80 PSI Internal Bypass, 3/8" NPT-Female ports, Nylon Housing What does the "internal Bypass" mean? Answer: This means the pump can be used in both open flow and partially occluded use where non internal bypass have to be used either on or off. PUMP DESIGN: Positive Displacement 3 Chamber Diaphragm Pump CHECK VALVE: (2-Way Op) Prevents Reverse Flow & 6 Ft. Head Forward Flow CAM: 2.5 Degree MOTOR: Permanent Magnet, P/N 11-160-10, Thermally Protected VOLTAGE: 230VAC Nominal PRESSURE SWITCH: Adjustable Shut-Off (Range 80-110 PSI) Factory Set @ 100 PSI, Turn On 75 PSI 5 PSI LIQUID TEMPERATURE: 180 Degrees Fahrenheit (82 Degrees Centigrade) Max. PRIME: Self-Priming Up To 9 Ft. Vertical, Max. Inlet Pressure 30 PSI (2.1 Bar) PORTS: 3/8"-18 NPT Female MATERIAL OF CONSTRUCTION: PLASTICS- Nylon VALVES- EPDM DIAPHRAGM- Santoprene FASTENERS- Zinc Plated Steel NET WEIGHT: 4.8 Lbs (2.18 Kg) DUTY CYCLE: Intermittent (See Temperature Rise Chart) TYPICAL APPLICATIONS: Soil Extraction BYPASS: 100 PSI APPROVALS: VDE Approved MOTOR RATING: 50/60 Hertz