Pump bypass

Low gear oil pump bypass/relief valve setting. 

If we shut off the pump in the system in Prob. 6.56 and open the bypass around it, what are the j maximum and minimum values of the flow Which way does it go Neglect the friction losses in the pump bypass line. Assume that the globe valve is always wide jjpen. 

Excessive internal pump bypassing (worn wear rings) or external pump bypassing (through a discharge to suction recycle line) also takes more horsepower. A useful troubleshooting tool for pump motor problems is a permanently mounted ammeter. 

Hematologic In a retrospective review of 453 patients who underwent off-pump bypass graft surgery and who received clopidogrel preoperatively (n = 101) or not ( = 352), clopidogrel was associated with higher intraoperative and postoperative... 

Example of a single-channel manifold for use in flow injection analysis where R1 is a reagent reservoir P is the pump S is the sample I is the injector B is a bypass loop ... 

Two examples of dual-channel manifolds for use In flow Injection analysis where R1 and R2 are reagent reservoirs P Is the pump S Is the sample I Is the Injector B Is a bypass loop W Is waste C Is the mixing and reaction coll and D Is the detector. 

Fig. 6. Homogenizer used as a timing pump for HTST pasteurization. Details of bypass, relief lines, equalizer, and check valves are not included (10).

The homogenizer can be used as a timing pump as it is homogenizing the product (Fig. 7), or both the timing pump and homogenizer can be used in the same system in the latter, appropriate connections and rehef valves must be provided to permit the product to bypass any unit that is not operating. 

The worldwide market for vascular grafts was approximately 150 million and growing at about 5% annuaUy as of 1995. The vascular graft area has tremendous market potential in development of smaU-diameter grafts of 3—4 mm for coronary bypass surgery. The total market for the intra-aortic baUoon pump, a cardiac-assist device, is ca 80 million worldwide. About 75,000 patients were supported by these baUoon pumps in 1994. This market is thought to have peaked. 

Install bypass piping back to suction vessel to increase flow through pump. Remember bypass flow may have to be as high as 50 percent of design flow. 

Bypassing is occurring between volute channels in a double-volute pump casing due to a casting defect or extreme erosion. 

Certain pump designs use an internal bypass orifice port to alter head-flow curve. High liquid velocities often erode the orifice, causing the pump to go farther out on the pump curve. The system head curve increase corrects the flow back up the curve. 

The thermocycle system can be operated only when condensing water is available at a temperature lower than the required chilled-water-supply temperature. Modifications for a centrifugal refrigeration unit include the installation of a small liqmd-refrigerant pump, cooler spray header nozzles, and a vapor bypass line between the cooler and the condenser. Without the compressor operating, a thermocycle capacity up to 35 percent of the refrigeration-unit rating can be produced. 

Hand-crimp the hose in back of the test leaf, and then turn on the vacuum pump and regulate the bypass valve on the pump to give the desired vacuum level in the receiver. 

FIG, 22-69 Flow schematic for stages-in-series. In operation, the block valves are open. All pump inlets are connected, but in such a way as to prevent feed bypassing a stage. (Coutiesy Koch Membrane Systems. )... 

The same procedure maybe used at other pump flows to permit plotting the series of balance-point curves as has been done in Fig. 29-61. From such curves, one can establish the maximum lean pump at any total tower outflow, and combining this with the semilean-pump performance curve results in Fig. 29-55. Bypass flow plotted in Fig. 29-55 is obtained by adding simultaneous lean- and semilean-pump flows and subtracting the recovery pump-turbine flow required to make the balance point at that lean-pump flow. 

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