Pumps, cleaning

If there are any spills when emptying or refilling a pump, clean them up immediately. Pump oils are not toxic, but such spills become slick and slippery and are considered accidents just waiting for someone to walk by. 

After 50 min, stop the pump, clean out all flasks and lines, and return to original conditions. To do this fill flask A with water. Prime the pump and let the system run at 2.0 mL/min with the injector handle in the inject position. Watch for the UV baseline to reestablish its initial position. 

These respirators pump clean air through a hose to the facemask. You am limited to working within the distance between the hose and the supply of clean air. 

Periodic-pump pulses Service or replace pulse damper purge air from pump clean or replace check valves. 

Pump clean solvent Into sample cell. 

Start with a low pressure flush (<4 bar g) by pumping clean water from the cleaning tank (or equivalent source) through the pressure vessels to drain for several minutes. Flush water should be RO/NF permeate or DI water, and free of hardness, transition metals, and also chlorine-free when using PA membranes. 

Pump clean solvent into sample cell... 

There are three main classes of respirators. One is a self-contained sources of breathable air. An example is a supplied air system carried by an individual. Usually there is a backpack that feeds clean air to a wearer s respirator. A second class is a supplied air system. It pumps clean air from one location to respirators worn by workers in a hazardous location. A third system involves air-purilying respirators that remove particulates and gases from inhaled air. Examples are respiratoiy protective equipment shown in Figure 28-3. 

If steam conditions are normal, loss of turbine horsepower is likely due to fouling of the turbine wheels. This fouling may be removed by condensate washing. With the compressor running, pump clean steam con-... 

General Observations Good housekeeping in the area, no visible indications of surface contamination. No signs of smoking or eating. Two desks had coffee cups. Scrapers and wire brushes not cleaned after use, but they are only used for the pump clean and they are kept in a small metal cabinet under the work bench that is dedicated to their storage. 

To lessen the risk of pumping sludges or slurries into a unit, the practice is to leave a safety margin of 50 cm (heel) below the outlet nozzle or install a strainer on the pump suction line. The deposits accumulate with time and the tanks are periodically emptied and cleaned. 

The chemistry of cement slurries is complex. Additives will be used to ensure the slurry remains pumpable long enough at the prevailing downhole pressures and temperatures but sets (hardens) quickly enough to avoid unnecessary delays in the drilling of the next hole section. The cement also has to attain sufficient compressive strength to withstand the forces exerted by the formation over time. A spacer fluid is often pumped ahead of the slurry to clean the borehole of mudcake and thereby achieve a better cement bond between formation and cement. 

Pipelines are cleaned and inspected using pigs . Pigs usually have a steel body fitted with rubber cups and brushes or scrapers to remove wax and rust deposits on the pipe wall, as the pig is pumped along the pipe. Sometimes spherical pigs are used for product separation or controlling liquid hold up. In field lines handling untreated crude may have to be insulated to prevent wax formation. 

Place 1 55 g. of clean sodium in a 250 ml. round-bottomed flask equipped with a reflux condenser. Add 40 ml. of absolute alcohol (or rectified spirit). If all the sodium has not disappeared after the vigorous reaction has subsided, warm the flask on a water bath until solution is complete. Cool the mixture and add 10 g. of p-acetylaminophenol. Introduce 15 g. (8 ml.) of ethyl iodide slowly through the condenser and reflux the mixture for 45-60 minutes. Pour 100 ml. of water through the condenser at such a rate that the crystalline product does not separate if crystals do separate, reflux the mixture until they dissolve. Then cool the flask in an ice bath collect the crude phenacetin with suction and wash with a little cold water. Dissolve the crude product in 80 ml. of rectified spirit if the solution is coloured, add 2 g. of decolourising carbon and filter. Treat the clear solution with 125 ml. of hot water and allow to cool. Collect the pure phenacetin at the pump and dry in the air. The yield is 9-5 g., m.p. 137°. 

Ethyl phenylethylmalonate. In a dry 500 ml. round-bottomed flask, fitted with a reflux condenser and guard tube, prepare a solution of sodium ethoxide from 7 0 g. of clean sodium and 150 ml. of super dry ethyl alcohol in the usual manner add 1 5 ml. of pure ethyl acetate (dried over anhydrous calcium sulphate) to the solution at 60° and maintain this temperature for 30 minutes. Meanwhile equip a 1 litre threenecked flask with a dropping funnel, a mercury-sealed mechanical stirrer and a double surface reflux condenser the apparatus must be perfectly dry and guard tubes should be inserted in the funnel and condenser respectively. Place a mixture of 74 g. of ethyl phenylmalonate and 60 g. of ethyl iodide in the flask. Heat the apparatus in a bath at 80° and add the sodium ethoxide solution, with stirring, at such a rate that a drop of the reaction mixture when mixed with a drop of phenolphthalein indieator is never more than faintly pink. The addition occupies 2-2 -5 hoius continue the stirring for a fiuther 1 hour at 80°. Allow the flask to cool, equip it for distillation under reduced pressure (water pump) and distil off the alcohol. Add 100 ml. of water to the residue in the flask and extract the ester with three 100 ml. portions of benzene. Dry the combined extracts with anhydrous magnesium sulphate, distil off the benzene at atmospheric pressure and the residue under diminished pressure. C ollect the ethyl phenylethylmalonate at 159-160°/8 mm. The yield is 72 g. 

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