Maximum operating pressure

Impact testing is not required if the design temperature is helow —29 C (—20 F) hut at or above —46 C (—50 F) and the maximum operating pressure of the fabricated or assembled components will not exceed 25 percent of the maximum allowable design pressure at ambient temperature and the combined longitudinal stress due to pressure, deadweight, and displacement strain (see Par. 319.2.1) does not exceed 41 MPa (6000 Ibfiin ). 

A difference between tank cars and most pressure vessels is that tank cars are designed in terms of the theoretical ultimate or bursting strength of the tank. The test pressure is usually 40 percent of the bursting pressure (sometimes less). The safety valves are set at 75 percent of the test pressure. Thus, the maximum operating pressure is usually 30 percent of the bursting pressure. This gives a nominal factor of safety of 3.3, compared with 4.0 for Division 1 of the ASME Pressure Vessel Code. 

The DOT rules require that pressure cars have rehef valves designed to hmit pressure to 82.5 percent (with certain exceptions) of test pressure (110 percent of maximum operating pressure) when exposed to fire. Appendix A of AAR Specifications de s with the flow capacity of rehef devices. The formulas apply to cars in the upright position with the device discharging vapor. They may not protec-t the car adequately when it is overturned and the device is discharging hqnid. 

Figure 16.1 shows part of a steel tank which came from a road tank vehicle. The tank consisted of a cylindrical shell about 6 m long. A hemispherical cap was welded to each end of the shell with a circumferential weld. The tank was used to transport liquid ammonia. In order to contain the liquid ammonia the pressure had to be equal to the saturation pressure (the pressure at which a mixture of liquid and vapour is in equilibrium). The saturation pressure increases rapidly with temperature at 20°C the absolute pressure is 8.57 bar at 50°C it is 20.33 bar. The gauge pressure at 50°C is 19.33 bar, or 1.9MN m . Because of this the tank had to function as a pressure vessel. The maximum operating pressure was 2.07 MN m" gauge. This allowed the tank to be used safely to 50°C, above the maximum temperature expected in even a hot climate. 

The turbine undergoes three basic tests, these are hydrostatic, mechanical, and performance. Hydrostatic tests are to be conducted on pressure-containing parts with water at least one-and-a-half times the maximum operating pressure. The mechanical run tests are to be conducted for at least a period of four hours at maximum continuous speed. This test is usually done at no-load conditions. It checks out the bearing performance and vibration levels as well as overall mechanical operability. It is suggested that the user have a representative at this test to tape record as much of the data as possible. The data are helpful in further evaluation of the unit or can be used as base-line data. Performance tests should be conducted at maximum power with normal fuel composition. The tests should be conducted in accordance with ASME PTC-22, which is described in more detail in Chapter 20. 

So = Maximum operating hoop stress level as determined by the Barlow formula using the maximum operating pressure. 

Note The sewer scaJ should be designed for a minimum of 175 percent of the drum s maximum operating pressure. 

Sephadex type Grade Dry bead diameter (/urn) Fractionation range peptides and proteins (g/mol) Fractionation range dextrans (g/mol) Swelling factor (ml/g dry Sephadex) Maximum operating pressure" (cm H,0) Permeability Ko Maximum linear velocity" (cm/hr) Swelling time (h) ... 

Assuming an eluent viscosity of 1 cP, K can be read from Table 2.1 and the theoretical linear velocity of an eluent at any given pressure can be calculated. For the less rigid Sephadex G types, the maximum operating pressures at which the relation between superficial velocity and applied pressure is still linear are given in Table 2.1. Exceeding the pressures listed will result in bead compression, a reduction in pore volume, and a decreased flow rate. 

Bead diameter (jum) Size exclusion pore dimension" (nm) Fractionation range Maximum operating pressure/velocity (kPa)/(cm/hr) Recommended operating linear velocity (cm/hr) pH stability (short term)... 

Column Bed volume (ml) Column dimensions [diameter (cm) x length (cm)] Column fittings Column materials" (Tube/Frit) Maximum operating pressure (kPa) Maximum linear velocity (cm/hr)... 

Column Column dimension (i.d. X L) (cm X cm) Bed volume (ml) Column materials° (Tube/Frit) Column fittings (inlet/outlet) Theoretical plates (N/m) Maximum operating pressure/flow rate (kPa)/(ml/hr)... 

Maximum operating pressure Maximum operating temperature... 

System Usual Condition of Maximum Operating Pressure... 

Design Pressure of a Vessel the pressure established as a nominal maximum above the expected process maximum operating pressure. This design pressure can be established by reference to the chart in Chapter 1, which is based on experience/practice and suggests a percentage increase of the vessel design pressure above the expected... 

For a new installation, establish pressure vessel normal maximum operating pressure, and temperature, and then the safe increment above this for vessel design conditions and determine the maximum allowable working pressure (MAWP) of the new vessel. (Have qualified fabricator or designer establish this. See pretious discussion of topic.)... 

Examination of the temperature control ranges of a process reactor reveals that the normal controls are to maintain a pressure of the reacting mixture of 80 psig, while the upper extreme could be 105 psig, which would be defined as the normal maximum operating pressure. 

These are used for hot water services with a maximum operating pressure of 5 bar and a maximum output in the order of 1500 kW. Site assembly of the unit is necessary and will consist of a bank of cast iron sections. Each section has internal waterways. 

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

Conventionally, the technique has been used off-line, to provide information on the structural integrity of equipment, typically during a pressure test. However, the technique can be used on line by periodically raising the pressure some 5-10% above the maximum operating pressure and one system... 

Maximum operating pressure, 33 Diaphragm metering pump, 214 DIERS, final reports, 523 Discharge coefficients, liquid flow, Q, chart, 118... 

The design pressure is 10% or 10-25 psi over the maximum operating pressure, whichever is greater. The maximum operating pressure, in turn, is taken as 25 psi above the normal operation. 

Spiral heat exchangers are compact units a unit with around 250 m2 area occupying a volume of approximately 10 m3. The maximum operating pressure is limited to 20 bar and the temperature to 400°C. 

DT = design temperature MOP = maximum operating pressure MOT = maximum operating temperature 3.40% baffle cut = 40% open area is a good rule-of-... 

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