Pump Maintenance Safety

Storage areas for maintenance, janitorial, and other service organizations must be provided. Safety items such as fire extinguishers, firehose cabinets, safety hoops on permanent ladders, guard rads, shielding for acid pumps, clearance for electric panel boards, etc, are needed. Manholes and cleanouts for sewer pipes within the facility as well as in the landscape and parking areas should be provided. 

Hi = Inlet head, or the losses expressed in feet that occur in the suction throat of the pump up to and including the eye of the impeller. These losses would not be registered on a suction pressure gauge. They could be insignificant, or as high as 2 feet. Some pump manufacturers factor them into their new pumps, and others don t. Also, changes occur in maintenance that may alter the Hi. If you don t know the Hi, call it a safety factor of 2 feet. 

The Hi, inlet head, is simply a. safety factor of 2 feet. Some pumps have an insignificant Hi. Other pumps have inlet losses approaching 2 feet. The Hi is losses to the fluid after it passes the suction pre,s,sure gauge and goes into the impeller eye. In a maintenance function, you can t be precise about what s happening to the fluid in this part of the pump. Just call it 2 feet. 

Determination of Reliability Characteristic Factors in the Nuclear Power Plant Biblis B, Gesellschaft fur Reaktorsicherheit mbH Nuclear Failure rates with upper and lower bounds and maintenance data for 17,000 components from 37 safety systems Data for pumps, valves, and electrical positioning devices, electric motors and drives from an operating power plant 66. 

Receivers also act as pump-down tanks, and should he capable of holding enough of the total refrigerant charge to permit evacuation of any one vessel for maintenance, inspection or repair. They should never he more than 85% full, to allow for expansion and safety. 

The checking and readjustment as necessary of all safety controls is an essential part of periodic maintenance - possibly annually. A time should be chosen when temporary stoppage of the plant will not cause inconvenience. Unsafe conditions can be set up by throtding valves, stopping pumps, or removing the load. In each case the relevant safety control should function at the pre-set conditions. Safety checks on specialized items such as fire dampers may be required from time to time by local authorities, and these checks, together with the expert advice available from the testing officers, should be welcomed as proof of the inherent safety of the installation. 

The second option considered was use of interception wells. One- or two-pump wells could be constructed at calculated spacings to create a hydraulic trough parallel to the canal to intercept the product. This design was considered more acceptable to the safety officer and the facility engineer, but was rejected by the maintenance foreperson because of the relative complexity of the operation system. The number of submersible pumps and sophisticated electronic controls would have required employment (or training) of technical specialists beyond the cost budgeted under normal operations. 

Many types of disposal system need regular maintenance and/or operator intervention to ensure they are available for use when required. Quench tanks should be filled with the correct quantity of quench fluid, and emptied and refilled after any. relief event. Scrubbers require pumps to operate correctly, and, in some cases, for an operator to check and adjust the concentration of chemicals within the circulating liquor. Again, good safety management is required. 

The MTBFs for all equipments are obtained from Center for Chemical Process Safety (1989) and the maintenance time is obtained from Bloch and Geitner (2006) (for pumps, compressors, valves) or estimated if the information is not available (for other equipments). Our example shows the results when the PM time intervals are optimized. Other variables are fixed ten employees, keeping inventory for all spare parts and reasonable numbers for the PM starting time. The maintenance model and the GA are implemented in Fortran running on a 2.8 GHz CPU, 1028 MB RAM PC. The final results for the fraction a (PM time interval = o MTBF) are shown in table 3. 

Chemical Co. s methyl acetate reactive distillation process and processes for the synthesis of fuel ethers are classic success stories in reactive distillation. Improvements for the Eastman process are very high five-times lower investment and five-times lower energy use than the traditional process. However, combining reaction and distillation is not always advantageous and in some cases it may not even be feasible. The methyl acetate process based on reactive distillation has fewer vessels, pumps, flanges, valves, piping and instruments. This is an advantage also in terms of safety and maintenance. However, a reactive distillation column itself is more complex (multiple unit operations occur within one vessel) and thus more difficult to control and operate. It is thus not possible to make unique conclusions. 

---