Pressure capabilities

Campbell R A and Goodman D W 1992 A new design for a multitechnique ultrahigh vacuum surface analysis chamber with high-pressure capabilities Rev. Sc/. Instrum. 63 172... 

The reaction is facilitated by elevated temperature necessitating pressure-capable, glass-lined reactors and exotic metallurgy for fittings to withstand the severely corrosive conditions. PAG product having 10—12% Al as AI2O2 can be produced. 

The partial containment system had many rooms in one room, with a pressure capability of about 26 psi, was the reactor core. The steam drums were in two rooms four main recirculation pumps were in each of two rooms. 

The pressure capability of silica-based columns extends beyond the range of organic polymers. Protein-Pak columns are stable to above 25 MPa (4000 psi), the smaller pore sizes to above 40 MPa (6000 psi). 

Higher pressure capabilities (compared to other types of rotary positive-displacement units). 

The capacity of a pump is determined by the number of plungers or pistons and the size of these elements (bore and stroke). A reciprocating pump is usually designed for a specific volumetric rate capacity and pressure capability. These factors are set by the application. Once the volumetric rate capacity and pressure capability are known, a designer can determine the plunger piston bore and stroke the rotation speed range and the power of the prime mover needed to complete the system. 

Compressors are rated as to their maximum volumetric flowrate they can operate at, and the maximum pressure they can maintain. These ratings are usually specified as standard cubic feet per minute (scfm) and psig. The scfm of volumetric flow rate refers to the compressor intake. The pressure rating refers to the output pressure capability. 

Aerated Mud. In aerated mud drilling operations, the drilling mud is injected with compressed air to lighten the mud. Therefore, at the bottom of the well in the annulus, the bottomhole pressure for an aerated mud will be less than that of the mud without aeration. However, an aerated mud drilling operation will have very significant bottomhole pressure capabilities and can easily be used to control potential production fluid flow into the well annulus. 

Thus the primary compressors will have sufficient pressure capability to drill the interval from 8,500 to 10,000 ft. A third primary compressor should be on site and hooked up for immediate service in the event of downhole problems or the necessity to shut down one of the operating compressors. Also, the booster should be hooked up for immediate service in the event of downhole problems. For more information and engineering calculations pertaining to compressors and boosters see reference 64. 

Reciprocating compressors are widely used by industry and are offered in a wide range of sizes and types. They vary from units requiring less than 1 Hp to more than 12,000 Hp. Pressure capabilities range from low vacuums at intake to special compressors capable of 60,000 psig or higher. 

Pumps are generally rated by their maximum operating pressure capability and their output in gallons per minute (gpm) at a given operating speed. 

Higher pressures can he obtained hy putting two axial-flow fans in series. If they are placed close together and contrarotated, the spin imparted hy the first can he recovered hy the second, and more than twice the pressure capability can be gained. 

For higher pressures, stopped flow injection has been used in which a valve releases the pressure in the column to atmosphere, at which point syringe injection at the top of the column (without septum) takes place. There has, however, been a trend in recent years to use valve injectors because of their generally high pressure capabilities and their ability to deliver large... 

Agilent Technologies introduced a Rapid Resolution Liquid Chromatography (RRLC ) system with pressure capabilities up to 600 bars. 

HPLC systems have recently become commercially available, which allow the use of pressures up to 1000 bar. Columns of particle size around 1.7 p,m and up to approximately 10-cm long can be operated at their optimum flow rate within the pressure capability of the system. The main advantage of these columns is that they can generate the same plate count as longer columns of larger particles but in a shorter analysis... 

A variety of soft seat materials are available, including PTFE and nylon. Since the shutoff pressure capability of ball valves is mnited by the load capabilities of the seat material, the upper temperature limit of soft seated valves is limited by the seat materim selection. The shutoff pressure rating of soft seated valves typically declines rapidly with increasing temperature, and the shutoff rating is often less than the body pressure rating. Metal seated valves do not are this characteristic. 

This clause prescribes minimum requirements consistent with designs existing at the time of publication. For future designs, it is considered a desirable design feature that the case MAWP match the pressure capabilities of the adjacent flanges. 

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.. 

The Mettler Instrument Corporation ( ) is the only source of an instrument with a simultaneous DSC—TGA—DTG capability, the TA 2000C, which can operate on a single specimen from ambient to 1200°C (with 1600°C capability in development) at ambient and reduced pressures in normal and corrosive atms. The Mettler Instrument Corporation has other instruments with subambient temp and high pressure capabilities... 

Compressor A device to increase gas pressure capable of causing the flow of gas. 

The normal stress extruder can also be used for melting, as shown in Fig. 6.30. However, because of the limited pressurization capability, various modifications have... 

Thus, for Newtonian fluids, the pressurization capability of the optimized JMP is eight times that of the SMP, and for non-Newtonian fluids, the ratio exhibits a minimum at n = 0.801 and rises to 11.59 at it — 0.25 whereas, the flow rate at fixed pressure rise for Newtonian fluids is 81 2 — 2.83 times in JMP as compared to SMP, and for non-Newtonian fluids with n = 0.25 it rises to 7.25. Clearly, the JMP configuration is about an order of magnitude more efficient then the SMP one. Moreover, the specific power input in a JMP configuration for Newtonian fluids is one-half that of the SMP, and for n — 0.25, it is one-fifth the corresponding ratios for specific power dissipated into heat are, one-quarter and 1/25, respectively. 

In vacuum company catalogues, one might see claims of their pumps total pressure and partial pressure capabilities. The partial pressure listing typically shows a better vacuum capacity than the total pressure because it is excluding condensable gases (thereby being a partial sample of the whole total pressure). For standard use, consider the listed ranges of the total pressure. It is unlikely (espe-... 

Swing lines made up of pipe with flexible joints and provided with a counterbalance is the preferred method of transferring hazardous chemicals into or from a tank vehicle. Hoses, no matter how thoroughly reinforced, have lower pressure capability and are easily damaged in use. Rupture of transfer hose is a not uncommon cause of employee injury or spill of product. Metallic tubing with braided exterior has admirable qualities, but a sharp bend, particularly near the end, causes weakening and failure, which is often neglected before the failure. 

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