Adjustment shall be by means of readily accessible dial knobs, one for changing stroke length and the other for changing stroke frequency. Both knobs are to be located opposite the liquid handling end.
Drive
The pump drive shall be totally enclosed with no exposed moving parts. Solid state electronic pulser shall be fully encapsulated and supplied with quick connect terminals at least 3/16" (4.75 mm) wide. Electronics shall be housed in chemical resistant enclosure at the rear of the pump for maximum protection against chemical spillage. Electrical power consumption shall not exceed 29 watts per hour under full speed and maximum pressure conditions. Pump weight shall not exceed 15 lbs (6.9 kg).
Automatic Pressure Relief
To eliminate need for pressure relief valve, LiquiframTM shall automatically stop pulsating when discharge pressure exceeds pump pressure rating by not more than 35%.
Material
Chemical metering pump housing shall be of chemically resistant glass fiber reinforced thermoplastic. All exposed fasteners shall be stainless steel. Chemical metering pump valves shall be ball type, with ceramic balls . Valve seat and seal ring shall be renewable by replacing the combination seat-seal ring or cartridge valve assembly. Pump head shall be of transparent acrylic material capable of resisting the pumped chemical. Fittings and connections at pump head shall be PVC.
Check Valves And Tubing
A total of 16 ft (4.8 m) of polyethylene tubing shall be provided per pump complete with compression connections. A foot valve with integral one piece strainer shall be provided for the suction line, and an injection/back pressure check valve with 1/2" NPT male connection for the injection point. The injection check valve shall incorporate a dilating orifice which prohibits scale formation and accumulation of crystalline deposits.
