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Pump Limits
You should note the limits of your Optos pump. Exceeding or violating these limits may damage your pump and
will void your warranty.
Viscosity Limits
Liquids with viscosities of 100 centipoise or higher often reduce nominal flow rate values. You cannot pump
liquids with viscosities exceeding 500 centipoise.
Chemical Limits
Some buffers, particularly halide salts at high concentrations, can cause corrosion of type 316 stainless steel. If
you leave buffers in the pump, crystallization may occur and cause damage to the seal material. Some solvents
can swell the plastic material in the valves or the piston seal. Usually, you can substitute less damaging fluids,
and you can minimize potential damage by carefully flushing the pump. You can sometimes substitute special
materials; please consult with the factory.
Mechanical Limits
Pumped fluids should be free of particulate matter, since clogged valves may result in erratic flow rates. We
strongly recommend the use of a filter on the inlet line to protect the valves from small particles. A 10 micron
sintered stainless steel filter is available from Eldex (Part No. 5776) and is suitable for most applications. When
you need to avoid metal, a 10 micron plastic filter is available from Eldex (Part No. 1279).
Damage to the mechanical parts will result from subjecting the pump to excessive pressure. Do not try to pump
fluid against pressures which exceed the maximum pressure capability of your model.
Temperature Limits
Eldex pumps are designed to operate under ambient temperature conditions. If you take appropriate precautions
to prevent condensation, you can use the pump in a cold room. Do not use the pump in an environment which
exceeds 35ºC.
It is possible to pump fluids which are at elevated temperatures. Although the reaction of specific fluids at
elevated temperatures to the wetted parts may vary, it is usually the plastic materials in the liquid end which will
be of concern. Generally, the CTFE maintains integrity at temperatures up to 200ºC. The PTFE piston seal
material is generally good to 260ºC. You will want to consult the factory when pumping fluids at elevated
temperatures if there is any question in your mind about how the wetted parts will react.
Shutdown Procedures
Eldex pumps are manufactured using materials selected to resist corrosion. However, some buffers, most
notably halide salts at high concentration, are capable of corroding type 316 stainless steel, and some solvents
are capable of distorting CTFE or other plastics used in the pumps. Therefore, it is important to flush the pump
after using any potentially damaging materials.
To flush the pump, first pump distilled water to remove any salt(s) or solids. You should do this for a minimum
of ten minutes as soon as possible after using the pump. Next, you should flush the pump with an inert solvent
such as methanol for at least five minutes.
CAUTION: It is important to note that salts and buffers can lead to corrosion of stainless steel or distortion
of plastics if they are left in contact with the pump for long periods of time. Failure to flush potentially
corrosive substances from the pump may void your warranty.
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