Check valve efficiency

Day-to-day variations in flow rate, check valve efficiency, or mixing solenoid performance (in binary, ternary, or quaternary pumping systems) can also contribute to retenbon shifts. Therefore, compound identification should be performed only by spiking with a known standard or by direct identification with, for example, mass spectral analysis. 

Auxiliaries are additional boiler fittings that provide controls for ease of operation. They may include additional valves (such as check valves on feed lines, nonreturn valves on steam distribution lines, and the various boiler system drain valves), gauges, connections, and devices to regulate FW, air, and fuel and to provide for the efficient production, pressure, temperature, quality, and flow of HTHW or steam. 

An oil with a 32.6° API gravity at 60°F is to be transferred from a storage tank to a process unit that is 10 ft above the tank, at a rate of 200 gpm. The piping system contains 200 ft of 3 in. sch 40 pipe, 25 90° screwed elbows, six stub-in tees used as elbows, two lift check valves, and four standard globe valves. From the pump performance curves in Appendix H, select the best pump to do this job. Specify the pump size, motor speed, impeller diameter, operating head and efficiency and the horsepower of the motor required to drive the pump. 

After another review of the practical constraints and technical considerations, it was concluded that an eductor vacuum-enhanced recovery system would be feasible and still be cost-effective and efficient. In all, 11 6-in.-diameter wells extending to a depth of 28 ft were installed at strategic locations in the area where product seeps were observed. Each well was serviced by a high-pressure supply and a low-pressure return line. A basic domestic-type deep-well eductor was installed in each well, attached to a drop pipe that extended to 25 ft below the surface. A check valve on the drop pipe prevented backflow into the well during service. The top of the casing... 

Basically, no special devices have been developed to handle mobile phases in nano-HPLC. However, our experience dictates that reservoirs small in volume and of high quality glass are preferred for this purpose. Solvent containers should be air tight and free from any contamination. The use of helium gas, through a sparging device, may be beneficial for degasification of solvents in nano-HPLC, which can improve check valve reliabilities, especially at nano flow, and diminish baseline noise in UV detection. Besides, each reservoir should be equipped with a shutoff valve for efficient helium consumption [9]. 

The precision of both piston and diaphragm reciprocating pumps depends greatly on the efficient functioning of the reservoir and column ball check valves, which must be perfectly designed. They are made of stainless steel or, for miniTHal wear, sapphire. Sometimes the seats of the check valves are in sapphire and the balls in ruby. The pistons can be made of stainless steel, glass or sapphire. 

A set of pumps in a pit recirculates the cooled water. Submerged vertical pumps are standard in this service. When using multiple pumps with large capacities, it is necessary to space them properly and to design the pit to allow unimpeded access of the water flow to the suction of the pumps. The requirements of the pump vendors will fix this aspect of design. Any reverse flow through idle pumps recycles to the basin and reduces the efficiency of the process. Check valves and anti-reverse mechanisms help to prevent this. 

The plant arrangement assumed for the two Brayton system heat balance is illustrated in Figure 5-27. This system has two converter loops each with one turboaltemator, recuperator, and gas cooler. No cross-strapping of converter loop components is assumed. Each turboaltemator Is sized to produce the entire 200 kWe required for full power. The recuperator and gas cooler are appropriately sized to meet this power requirement. One converter loop is normally operating while the other is an idle spare A check valve is located at the outlet of each compressor to prevent backflow through the idle loop to maximize system efficiency, minimize bypass cooling flow around the reactor, and prevent potential damage to turbomachinery due to reverse rotation. An isolation valve installed the outlet of each compressor enables loop shutdown and startup evolutions and provides Brayton overspeed protection for certain electric plant casualties. 

Check valve seat leakage was required to be minimized to the lowest level practical. A preliminary design goal of a maximum target value was set to no greater than 0.5% of the mass flow rate when tested with helium per an established test method when seated with the baseline system dp of 100 kPa. This requirement may be necessary to minimize the impact on overall system efficiency and prevent reverse rotation of a Brayton, although some allowable leakage may be desirable. 

If an isolation valve stuck in the open position it would preclude the ability to isolate a loop. Also, if it partially closed, it would significantly increase system pressure drop thereby reducing system efficiency and could result in stalling an operating Bra on unit. If a check valve stuck open, it would lower plant efficiency. The potential causes and actions to mitigate this failure mode are consistent with those discussed in 9.S.5.3. 

If the check valve or control valve fails to fully open in an operating loop, the valve will present a flow restriction in the loop. The overall system pressure drop will increase whiie reducing system mass flow rate, reducing the thermal efficiency oHhe system. A flow imbalance between the operating loops will exist because flow through the unrestricted loop will increase until its pressure drop equals that of the restricted loop. If the flow restriction is too severe, the reactor module may not be able to generate the required electrical power. 

Most combustion equipment is not controlled by means of a feedback from flue gas analysis but is preset at the time of commissioning and preferably checked and reset at intervals as part of a planned maintenance schedule. It is difficult to set the burner for optimum efficiency at all firing rates and some compromise is necessary, depending on the control valves used and the control mode (e.g. on/off, fully modulating, etc.). 

The purge gas flow rate is kept constant at = 80 mL/min by a metal bellows flow controller (Porter Instruments, VCD-1000, see Fig. 23-1). A toggle valve downstream of the flow controller is used to stop the gas flow for maintenance of the system or for determination of extraction efficiencies, etc. The purity of the purge gas is checked by running the analytical programme without injection of seawater. 

After checking the interface level, consider the mix valve as a possible cause of the carry-over problem. To get good contacting between the hydrocarbon and wash liquid, a pressure drop of 10 psi to 25 psi is about right. Use the same pressure gauge to check pressure up and downstream of the mix valve. Try reducing the pressure drop to 10 psi and see if the carry-over problem is diminished. Remember that setting it too low can decrease hydrocarbon cleanup efficiency. 

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