Pumps problems with

Pumping Problems with Residual Fuel and Marine Fuel Oils... 

Sodium pumps. Problems with the pumps resulting in unplanned energy losses occurred in 1981-1985, and were caused by unstable operation of the pump speed control stem. Impulses from the electric motors caused failures of the pump-motor couplings, and increased vibration and fatigue cracks in the pump shafts. The use of advanced shafts and couplings and changing to a steady mode of pump operation after attaining the preset reactor power level have eliminated any failures of the reactor coolant pumps since 1985. 

This procedure has been tested for a lot of bees and conditions are similar. Displl solvent and distill ketone with a water pump. My yield, 41 grams, about 75 %. Scaling. Of course. This procedure have been done with 150 cc of safrol, but with T75 I of methanol with simiair yields, so I ve prefered to present this version wich is better (less solvent, less time) Addition of nitrite i/vas done in 2,5 hours. When scaling, water in B can be decreased if we have problems with our volume flasks, but this means a lot of NaN02 is not dissolved, so each 15 minutes, we close sep. funnel, and shake B a bit, and when there is no foam, we can open sep. funnel again (1 drop or abit more /second). My opinion is 150 is ok, but theorically you can scale more. More time rxn is not a problem for product. 

Rotational viscometers often were not considered for highly accurate measurements because of problems with gap and end effects. However, corrections can be made, and very accurate measurements are possible. Operating under steady-state conditions, they can closely approximate industrial process conditions such as stirring, dispersing, pumping, and metering. They are widely used for routine evaluations and quahty control measurements. The commercial instmments are effective over a wide range of viscosities and shear rates (Table 7). 

Change process to adjust specific gravity to design value, or throttle pump to reduce horsepower requirements. This will not correct problem with some vertical turbine pumps that have a flat horsepower-required curve. 

Eoint-source pump of limited capacity. Experience has indicated that earings are a serious problem with mechanical-aeration equipment. Wave action generated within the aeration tank tends to produce lateral stresses on the bearings and has resulted in failures and increased... 

The most common maintenance problem with centrifugal pumps is with the seals. Mechanical seal problems account for most of the pump repairs in a chemical plant, with bearing failures a distant second. The absence of an external motor (on canned pumps) and a seal is appeahng to those experienced with mechanical seal pumps. 

Artificial pumped storage reservoirs, such as those built to supply London, have been constructed to reduce problems with algae. These have a circular design, with pumped inflows which are jetted to mix fully the water colnmn. " However, although these effectively deal with eiitrophic water, they are not solutions which are normally used for rehabilitation of eiitrophic lakes. 

To avoid problems with this pump during the proeess, be sure the pump eurve indicates NPSHr less than 8 ft at the duty point. 

If your pump is in cavitation, you ll have one or more of the following Problems with pump packings. 

The information on the dash panel is located right in front of the eyes of the operator of the ear. It s a shame that most pump operators don t have their control panel (the curve) before their eyes, or even within reach, as they operate the pumps. This is the source of many problems with pumps. 

It is neeessary to understand the TDH and it s eomponents in order to make eorreet deeisions when parts of the system are changed, replaced, or modified (valves, heat exchangers, elbows, pipe diameter, probes, filters, strainers, ete.) It s neces.sary to know these TDH values at the moment of specifying the new pump, or to analyze a problem with an existing pump. In order to have proper pump operation with low maintenance over the long haul, the BF P of the pump must be approximately equal to the TDH of the system. 

This is the beginning of many problems with pumps. A pump is sf d with at one set of system coordinates. Then the system (the TDH) goe " mi and the pump moves on its curve away from its BEP out to one or the oth( i It is necessary to determir- i -num and minimum tions in the design the pump within these elev ions. If the system continues to pump, you ll either have to modify t ... /stem or modify or change the pu.-you really like to change bearin, . .d seals. 

A big part of the overall problem with adequate mechanical. seal life is trying to make a precision mechanical seal run into the same. space that previously was occupied by the packing rings. Pump design evolved over time to accommodate the packing rings. 

Look for the evidence - The evidence is the manifestation of the symptoms. The evidence indicates that there is a problem with the pumping system. Example the discharge gauges indicate a low pressure . 

If the drum may occasionally receive water, caustic or similar aqueous streams, which would create problems in receiving facilities if pumped out with the hydrocarbon, then means of separate drainage should be be included. This may consist of a connection to the sewer from the bottom of the boot or in the case of sour water, a connection off the pumpout pump discharge routed to sour water facilities or other suitable disposal. 

Problems with controLrod drive mechanism and/or 24. Loss of condensate pumps (all loops)... 

Makay, E., How to. Avoid Field Problems With Boiler Feed Pumps, Hydrocarbon. Processing, V. 55, No. 12, 1976. 

Yedidiah, S., Unusual Problems with Centrifugal Pumps, Chem. Eng, V. 93, No. 23, 1986. 

McNally, L. Increase Pump Seal Life, Hydro. Proc. V. 58, No. 1, 1979. Lapp, S., Hotv to Avoid Problems with Cold Service Pumps, Hydro. Proc., V. 60, No, 1, 1981,... 

A Class 5 installation follows the Class 4 concept, but is characterized by having pumps operating with identical spares and have one or more pumps operating in plant bays where product storage gives time to assess the problem and to take action to get the pump back on-line. 

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