Pressure surge

The maximum pressure surge is obtained when the valve closes in less time than the period T required for the pressure wave to travel from the valve to the pipe inlet and back, a total distance of 2L. 

The pressure surge will be reduced when the time of flow stoppage exceeds the pipe period T, due to cancellation between direct and... 

Pressure Surge. Not enough NPSHa. Air aspirated or air pockets at the suction line. Entrained Air. Plugged impeller. 

Effects. Trays can become damaged several ways. A pressure surge can cause damage. A slug of water entering a heavy hydrocarbon fractionator will produce copious amounts of vapor. The author is aware of one example where all the trays were blown out of a crude distillation column. If the bottom liquid level is allowed to reach the reboiler outlet line, the wave action can damage some bottom trays. 

Investigate the effect of the pressure surge on adjacent equipment per the 1997 edition of API RP-521. The design pressure of adjacent equipment and piping may be exceeded during a tube rupture. This is of special concern in cooling water networks. Dynamic simulation can assess the impact of a tube rupture on adjacent equipment and identify corrective measures. 

Combinations of water and hot hydrocarbon releases which could result in steam generation and pressure surges. 

Supporting the hydrated ferric oxide chips is a combination of a perforated, heavy metal support plate and a coarse support packing material. This material may consist of scrap pipe thread protectors and 2-3-in. sections of small diameter pipe. This provides support for the bed, while offering some protection against detrimental pressure surges. 

Ten years later, there was a pressure surge on the cooling water lines when the cooling water pumps were ehanged over this caused a sample... 

What is the pulse amplitude (pressure surge) for the various flowrates when the puppet valve travels from 0.2 to 0.5 in. At what position will we have a half-height pulse ... 

Propene at 955 bar and 327°C was being subjected to further rapid compression. At 4.86 kbar explosive decomposition occurred, causing a pressure surge to 10 kbar or above. Decomposition to carbon, hydrogen and methane must have occurred to account for this pressure. Ethylene behaves similarly at much lower pressure, and cyclopentadiene, cyclohexadiene, acetylene and a few aromatic hydrocarbons have been decomposed explosively [1], It is mildly endothermic (AH°f (g) +20.4 kJ/mol, 0.49 kJ/g) and a minor constituent of MAPP gas [2],... 

Dining preparation of an unspecified oxime, the carbonyl compound, pyridine, hydroxylamine hydrochloride and sodium acetate were heated in a stainless steel autoclave. At 90°C a sudden reaction caused a pressure surge to 340 bar, when the bursting disk failed. The reaction had been run previously and uneventfully on one-tenth scale in a glass lined autoclave. 

TAREX A process for destroying hydrocarbons, organic wastes, and hydrogen chloride by controlled combustion in a special combustion chamber which can withstand sudden pressure surges. Engineered by KEU Energie- -Umwelttechnik, Germany. 

Upon termination of the experiment, all parts of the apparatus should be evacuated once again, before the liquid nitrogen bath is removed. The same precaution should also be maintained during removal of the bath, in order to safeguard against pressure surges caused by thermal expansion of the residual hydrogen or due to sudden desorption from the charcoal. 

Four aspects of unsteady fluid flow will be considered in this chapter quasi-steady flow as in the filling or emptying of vessels, incremental calculations, start-up of shearing flow, and pressure surge in pipelines. 

Pressure surge can be controlled by the use of surge vessels connected to the pipeline with a gas space above the liquid. If a pressure surge passes along the pipeline, liquid flows into the vessel through a check valve and the gas is compressed. Another valve then lets out the liquid at a controlled rate. This type of arrangement is used in large hydraulic lines. 

Dies are shaping devices that operate at a rate that is directly proportional to the upstream pressure. Thus, if the pressure to the die is not constant then a variable rate will occur at the die opening, causing the dimensions of the product to vary. Rate surges at the die can be estimated from the pressure surges using the... 

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