HIGH TEMPERATURE PROBLEMS WITH PUMPS AND SEALS H020
High temperature is defined as too hot for one of the pump or seal components, or hot enough to make the product you are pumping change state from a liquid to a gas, vapor, crystal, solid, etc.
High temperature pump and seal applications have several special needs:
- A jacketed stuffing box that is designed to isolate the pumpage from the stuffing box contents. This is normally done by locating a non-conducting thermal bushing into the end of the stuffing box and circulating a coolant through the stuffing box jacket. Carbon is a good choice for the bushing. Use as much axial length as space will allow.
- A centerline pump design to compensate for thermal expansion.
- A cartridge seal design that allows open impeller adjustment after the pump has come up to operating temperature.
- A stainless steel shaft to retard heat transfer to the bearings.
- A method of cooling the bearing oil, but never the bearings because the outer race will shrink, increasing the load on the bearings.
- A method of retaining motor to pump alignment during the temperature transients. A “C or D” frame adapter will probably be your best choice.
- A coupling that will compensate for axial expansion.
- Replace bearing grease seals with metallic labyrinth seals