Pumps maximum pressures

Booster Pump. Use of a centrifugal booster pump avoids a low intake pressure, particularly for large, high volume units. A low pressure (>26.6 kPa (200 mm Hg)) on the iatake of a timing pump can cause vaporization of the product. The booster pump is ia the circuit ahead of the timing pump and operates only when the FDV is ia forward flow, the metering pump is ia operation, and the pasteurized product is at least 7 kPa (1 psi) above the maximum pressure developed by the booster pump (Fig. 8). 

Pipe-hue pumping stations usually range from 16 to 160 km (10 to 100 miles) apart, with maximum pressures up to 6900 kPa (1000 Ibf/ in") and velocities up to 3 m/s (10 ft/s) for liquid. Gas pipe lines have higher velocities and may have greater spacing of stations. 

The vessel was designed to withstand Ihe maximum pressure the pump could deliver. The relief valve was not designed to take the maximum flow from the pump. 

Total Pressure Loss. Since bit life is not an issue in a short deviation control motor run operation, it is desirable to operate the positive displacement motor at as high a power level as possible during the run. The motor has a maximum pressure loss with which it can operate. This is 580 psi (see Table 4-114). It will be assumed that the motor will be operated at the 580 psi pressure loss in order to maximize the torque output of the motor. To obtain the highest horsepower for the motor, the highest circulation flowrate possible while operating within the constraints of the surface mud pump should be obtained. To obtain this highest possible, or optimal, circulation flowrate, the total pressure losses for the circulation system must be obtained for various circulation flowrates. These total pressure losses tabulated in the lower row of Table 4-117 represent the surface standpipe pressure when operating at the various circulation flowrates. 

Pump Limitations. Table 4-116 shows there are six possible liner sizes that can be used on the Model E-700 mud pump. Each liner size must be considered to obtain the optimum circulation flowrate and appropriate liner size. The maximum pressure available for each liner size will be reduced by a safety factor of 0.90. The maximum volumetric flowrate available for each liner size will also be reduced by a volumetric efficiency factor of 0.80 and an additional safety factor of 0.90. Thus, from Table 4-116, the allowable maximum pressures and allowable maximum volumetric flowrates will be those shown in Figures 4-207 through 4-212, which are the liner sizes 5j-, 6, 6-[, 6- and 7 in., respectively. Plotted on each of these figures are the total pressure losses for the various circulation flowrates considered. The horizontal straight line on each figure is... 

In a further treatment we shall deal with Eqs. (14) and (14a) under such conditions only, which make the terms with (d2P/dt2)m and d,PJ dQp max negligible as compared with the other terms. Using Eq. (13) we can eliminate from Eq. (14) the unknown value of the surface coverage 0 and thus arrive, for a given pumping speed S and heating rate dT/dt, at a relation between the measured data (i.e. the maximum pressure Pm or the maximum partial pressure Pam, and the corresponding temperature Tm) and the parameters fed, K, Ed, — AH, and x, characteristic of the surface... 

A centrifugal pump is to be used to produce a 150-psi head at a flow rate of 80 GPM. The maximum pressure in the system will be 200 psi and the maximum temperature is 220°F. A corrosive fluid is being pumped, and it must be determined whether a stainless-steel or cast-iron pump is to be used. The cast-iron pump will last 3 years while the stainless-steel pump will last 7 years. Assume that in 1968 it cost 250 in labor costs to replace a pump. Assume overhead costs involved with obtaining a pump come to 15% of its cost. Assume money is worth 12%. (For other costs see Appendix B)... 

For example for the preparation of a 15 cm long, 4.6 mm i.d. stainless tube column, 2.5 g of octadecyl-bonded silica gel was suspended in 25 ml of hexanol-methanol mixture, and kept in an ultrasonic bath for a few minutes to remove air. After the reservoir was filled with the slurry, methanol was pumped in at 10 ml min -1 under constant pressure, 45 MPa (450 bar). After the replacement of slurry solvent by methanol, the flow was stopped and the pressure allowed to drop. When 0 MPa was reached the reservoir was removed. Then, 20 ml of water was added and methanol was again pumped in under the same conditions as before. Again, the flow was stopped and the pressure allowed to drop until it reached 0 MPa. The pre-column was removed and the analytical column closed. The maximum pressure that can be applied in the filling stage is based on the pore size, particle shape, and purity of the silica gel. This reproducible packing procedure is performed at constant temperature by using a water bath (60-BO °C). 

Fire water mains should be designed to handle the maximum pressures developed by fire water pumps. Systems operating at pressures over 150 psi (1,034 kPa) are discouraged, as this would exceed the normal design pressures for most fire protection assets such as monitors, hydrants, etc. 

However, it has been mentioned before, and must be bourne in mind, that it is not the pressure capability of the solvent pump that normally determines the maximum pressure that can be employed, but the maximum pressure the whole chromatographic system can tolerate. Although valves have been designed to operate at 10,000 p.s.i., or even higher, their useful lifetime at that pressure is often relatively short, usually as a result of sample contamination scoring the valve seats. For long-term continuous operation the maximum inlet pressure a valve can tolerate is often only about 3000 p.s.i.. 

For examination of an expl a charge(usually 50 to 300 g) is placed inside the bomb, and, after closing the lid, the air ib evacuated by means of a vacuum pump. Then foe chge Is fired electrically and the pressure diagram ia obtained. Method of computation of results is given in Ref 2. The result thus obtained ia termed foe "maximum pressure of the explosive in its own volume" ... 

Provisions for safe and rapid isolation of piping systems and equipment Use piping, gaskets, and valves that take advantage of modern technology Use strong vessels to withstand maximum pressure of process upsets Avoid inherently unsafe equipment Use pumps suitable for hazardous service... 

To feed the system with starting materials, rotary pumps with ceramic pump heads are used. The flow rate can be adjusted from 0.1 to 45 ml min-1 and a maximum pressure of 7 bar. Depending on the demands of the chemical reaction, the system can also be equipped with three-way, pressure relief and check valves. 

Mercury diffusion pumps may be used in the lab to produce a high vacuum. Cold traps are generally placed between the pump and the system to be evacuated. The traps cause the condensation of mercury vapor, which prevents diffusion back into the system. The maximum pressure of mercury that can exist in the system is the vapor pressure of mercury at the temperature of the cold trap. Calculate the number of... 

Parallel-Plate Flow of Newtonian Fluids A Newtonian polymeric melt with viscosity 0.21b(S/in2 and density 481b/ft3, is pumped in a parallel-plate pump at steady state and isothermal conditions. The plates are 2 in wide, 20 in long, and 0.2 in apart. It is required to maintain a flow rate of 50 lb/h. (a) Calculate the velocity of the moving plate for a total pressure rise of 100 psi. (b) Calculate the optimum gap size for the maximum pressure rise, (c) Evaluate the power input for the parts (a) and (b). (d) What can you say about the isothermal assumption ... 

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