N200M model flexible impeller pumps from Oberdorfer include the option of either pedestal or flange mount. The bronze construction and stainless steel shaft ensure corrosion resistance. N200M have 3/8" suction and discharge ports, mechanical carbon ring, standard neoprene impellers, machined-in cam and separate drain openings in the seal and bearing areas. Common marine applications include engine cooling, bilge, water circulation, ballast transfer and wash-down. Industrial applications include mixing, liquid circulation and sump drainage.
Either direct drive with flexible coupling or pulley drive can be used. Make sure both flexible coupling halves are properly aligned. When using pulley, do not over tighten belt.
Liquids compatible with neoprene can be pumped including fresh and salt water solutions and mild chemicals. Do not pump severe solvents or acids. When possible, flush pump with fresh water after each usage. Extremes of cold and heat will affect impeller life. Limits of 40° to 140° F should be observed. Do not allow liquid in pump to freeze. Drain pump by loosening cover screws. Use methyl alcohol based anti-freeze compounds.
Suction lift of 15 feet is possible when impeller is wet. Suction lines must be air tight in order for pump to self prime. A foot valve at beginning of suction line is recommended.
The impeller must be replaced if it is worn out or has been damaged by debris or by running the pump dry. Symptoms of a defective impeller are low pumping pressure and low flow causing overheating of the engine. Poor pump performance can also be caused by slippage of V-belts, so belts should be checked for tightness. To replace the impeller remove screws and cover. Pull out the impeller with nose pliers or two screwdrivers. Be careful not to dent the pumping chamber with these tools. When inserting new impeller, line pin in impeller with the slot in the shaft. Use oil on shaft and avoid forcing the impeller onto the shaft. The impeller should also be removed for storage periods to prevent the blades from taking a permanent set.
If water drips from the weep hole or from the area where the shaft exits the pump, the seal is defective and must be replaced. Prolonged running of the pump with a leaky seal can destroy the ball bearings resulting in catastrophic pump failure and engine shut-down. For seal replacement, the pump must be removed from the engine and disassembled in order to gain access to the seal area. Where mechanical seals are used, both components (stationary and rotating member) must be replaced at the same time.
Pump will operate satisfactorily when mounted in any position. DO NOT RUN DRY. Rubber impeller pumps generate high rubbing friction unless lubricated by liquid pumped. Lack of liquid will cause impeller to burn up.