Pump running roughly

Driver troubles. Uncouple the motor from the pump. If the driver runs roughly when uncoupled, send it to the shop. The pump is OK. 

The ordinary 3,600-rpm electric motors used to drive refinery pumps are quite reliable. If an uncoupled motor is running roughly, the bearings need replacement. This is often due to insufficient lubrication. 

If you think a motor is running rough because of bad bearings, have it uncoupled from the pump. Run the motor alone, and see if the vibrations persist. Motor bearings commonly fail because of a lack of lubrication. 

The use of pilot-plant filter assemblies is both eommon and a elassieal approaeh to design methodology development. These eombine the filter with pumps, reeeivers, mixers, ete., in a single eompaet unit and may be rented at a nominal fee from filter manufaeturers, who supply operating instruetions and sometimes an operator. Preliminary tests are often run at the filter manufacturer s laboratory. Rough tests indicate what filter type to try in the pilot plant. 

If the starting time of a process is shorter than the total running time, technically the simplest method - the roughing and the holding pump - is used. Processes with strongly varying conditions require an adjustable throttle section and, if needed, an adjustable air admittance. 

Do not leave the gauge on for extended periods of time, especially when the pressure is only about 10 2 torr. Otherwise the gauge can contaminate quickly. Likewise, do not let the gauge run continuously while the system is roughing down. Brief use will limit the effects of the pumping action of the gauge. 

Within the enclosure, the 316 stainless steel reactor is sealed in a vacuum tight glass vessel at the bottom of which is a 5.08 cm window through which the incident and resultant laser beams pass. Up to 4 samples can be run at any time. The temperature in the reactor is controlled to 0.3°K at 800 K using a current proportional temperature controller [Honeywell UDC 5000]. The glass vessel containing the reactor is evacuated by a roughing pump initially, followed by a diffusion pump. 

The pump impeller resembles a hollow wheel with radial vanes. The diameter of this wheel can be trimmed down on a lathe. If an impeller with a 10-inch diameter is trimmed down to 9 inch, it will have a new performance curve below its former performance curve. Both the flow and head of the pump will be reduced. Also, the amp load on the motor driver will decrease. As a rough rule of thumb, reducing a pump s impeller diameter by 10 percent will reduce the amp load by 25 percent. Not only will this save electricity, but the motor wUl run much cooler. Unloading the motor by 25 percent may increase the Hfe of the motor windings by 10 years. 

---