Specific pressure

Finally, under the heading Specific pressure equipment requirements specific requirements are set out for equipment with a risk of overheating, for piping and, last but not least, specific quantitative requirements which set out a series of safety factors for certain pressure equipment. These latter provisions apply as a general rule which means that a manufacturer or a harmonised standard may deviate from these factors if it can be demonstrated that appropriate measures have been taken to achieve an equivalent level of safety. 

S ample Analysis. The fohowing procedure is used for sample analysis (/) after sample connections are made and the sample tubing purged for 30 minutes, the tubing is connected to the sampling manifold which serves to distribute sample gas to each of the analy2ers, and should analy2ers have specific pressure... 

Melt Index or Melt Viscosity. Melt index describes the flow behavior of a polymer at a specific temperature under specific pressure. If the melt index is low, its melt viscosity or melt flow resistance is high the latter is a term that denotes the resistance of molten polymer to flow when making film, pipe, or containers. ASTM D1238 is the designated method for this test. 

Because the objective of the calculation is now to calculate the distance at which a specific pressure occurs, rather than to calculate pressure at a given distance, calculations must follow a different order. 

If you require a disk for a specific pressure at elevated or cold temperature and want to determine if it is a standard disk, convert the required pressure at elevated or cold temperature to pressure at 72°F. 

AP = specific pressure drop, in. water/ft of packing APpb = specific pressure drop through dry bed, in. water/ft of packing Vs = superficial gas velocity, ft/sec pg = gas density, Ib/ft ... 

APpb = Specific pressure drop through dry bed, in. water/ft packing... 

In some hydraulic systems, it is necessary to maintain the system pressure within a specific pressure range for long periods. It is very difficult to maintain a closed system without some leakage, either external or internal. Even a small leak can cause a decrease in pressure. By using an accumulator, leakage can be compensated for and the system pressure can be maintained within acceptable range for extended periods. Accumulators also compensate for thermal expansion and contraction of the liquid due to variations in temperature or generated heat. 

These devices are generally designed to meet specific pressure-drop limitations. For ordinary installations operating at approximately atmospheric pressure, fan limitations dictate a maximum allowable pressure drop corresponding to a cyclone inlet velocity in the range of 20 to 70 feet per second. Consequently, cyclones are usually designed for an inlet velocity of 50 feet per second. 

Ideally, separators would present no resistance to ion transport. In practice, some resistance must be tolerated. Still, the resistance of the separator is usually insignificant relative to the transport limitations in the electrodes. Separator permeability is typically characterized by air permeability. The Gurley number expresses the time required for a specific amount of air to pass through a specific area of separator under a specific pressure (e.g., 10 mL through 1 in2 (6.45 cm2) at 2.3 cm Hg). This measurement depends on porosity, pore size, thickness, and tortuosity according to Eq. (1) [17] ... 

All three types of valves described above are on-off type devices (binary devices). A basic requirement in the design of these valves is that they offer minimum resistance to flow when open. For many types of calculations it is often justifiable to neglect pressure losses through such devices. But such a simplification cannot be applied to flow control valves. With these devices the control of flow is accomplished either by a constriction or by a diversion. In either case an additional resistance to the flow is introduced. Globe, angle, cross, and needle valves are typical devices of this type. Specific pressure drop correlations should be developed for such devices and used whenever possible. One such correlation used by Stoner (S5) takes the form... 

The volume measured at a specific pressure is directly related to the number of pores with that radius. 

It is also essential to consider that a specific pressure will not always cause a particular impact. Scale, both temporal and spatial, is one of the issues that determines the impact of a pressure. Other characteristics of the catchment area of the water body may also have an influence and the particular characteristics relates to the nature of the pressure. 

However, at some specific pressure the high-density polymorph becomes mechanically unstable. This low-pressure limit is seldom observed, since it often corresponds to negative pressures. When the mechanical stability limit is reached the phase becomes unstable with regard to density fluctuations, and it will either crystallize to the low-pressure polymorph or transform to an amorphous phase with lower density. 

Thus garnet, ileminite and perovskite are modifications stabilized by pressure and they are all stable at some specific pressure-temperature conditions. 

Gurley. Separator permeability is usually characterized by air permeability. The gurley number expresses the time required for a specific amount of air to pass through a specific area of separator under a specific pressure. The standard test method is described in ASTM-D726 (B). 

The multi-layer article is made using moulds between which a cavity clearance is freely set. A skin material lined with foam is placed between the upper and lower moulds and molten PP containing a chemical blowing agent is supplied through a resin melt conduit in the lower mould when the cavity clearance is between (C plus 15) mm and (C plus 50) mm, where C is the thickness of the skin material lined with the foam. The upper mould is lowered at a specific rate and the molten resin is pressed at a specific pressure to fill the cavity ends with the molten resin to complete the moulding of the resin body. The body is pressed for a certain time to form a skin layer, the upper mould is lifted up to decrease the compression pressure of the skin material lined with the foam to a pressure lower than the blowing pressure of the PP resin to form and solidify the foamed body, the upper mould is lowered to apply pressure to the moulded article and finally the article is cooled in the mould. 

Temperature of Explosive Decomposition 300° Temperature of Explosion 2700° Heat of Explosion 740cal/g, Specific Pressure 3250 atm/kg Volume of Gas Developed on Explosion, calcd at STP 325 liters/kg Trauzl Test value 30-40cc Impact Sensitivity with 2kg Weight 70cm and Velocity of Detonation 1400m/sec (See also Ref 28, p 345)... 

The following values for props of TNT are listed in Ref 31, p 241 Density (max) 1.58, Explosion Temperature 24(f, Flame Temperature at Explosion 2800°, Heat of Explosion 980kcal/kg, Detonation Velocity at d 1.5 6700m/sec, Volume of Gas at 0° 760mm 6801iters/kg, Specific Pressure 8100atm/kg,... 

Mf". Force or energy of expls, which is also called specific pressure (In French, force specifique). "f is the pressure (in atm) per unit area (cm2) that would be obtained by the expln of unit weight (1 g) in unit volume (1 cc), if the ordinary gas laws were applicable at that density... 

There s no one specific pressure unit you have to use when doing problems with Dalton s pcirtial-pressures equation. As long as the pressure units for all the gases are the same, you re good to go. However, if all the pressures given aren t in the Scime units, then some conversion must take place ... 

Some spray-equipment manufacturers have prepared useful detailed tables showing rate of delivery in gallons per acre per nozzle at several nozzle spacings, at specific pressures, and at different tractor speeds in miles per hour. 

Substance Charge g Pressure, kg/cm2 Erosion per Specific pressure / m... 

A low explosion temperature together with a great amount of gaseous products and a high specific pressure suggested the used of ammonium azide as a propellent explosive. In practice the use of the substance, however, is prevented by its high volatility. 

---