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Therefore, steam leakage takes place through the main valve and regulating valve, seals and glands, spaces between nozzles and moving blades, spaces between the diaphragm and shaft of the turbine, and; spaces between moving blade rings and the turbine casing. Leakage of steam through these gaps is a direct loss of energy.
Leakage in narrow clearance, spool valve. Hydraulic clearance. Flow in narrow clearances are of vital importance in hydraulic system component design. The flow in a narrow circular clearance of a spool valve can be calculated according to the formula below if the height is negligible compared to the width of the clearance, such as most of the clearances in hydraulic pumps, hydraulic motors ...
The use of the flow coefficient offers a standard method of comparing valve capacities and sizing valves for specific applications that is widely accepted by industry. The general definition of the flow coefficient can be expanded into equations modeling the flow of liquids, gases and steam using the discharge coefficient.
Valve leakage refers to flow through a valve which is set in the 'off' state. The importance of valve leakage depends on what the valve is controlling. For example, a dripping tap is less significant than a leak from a six-inch pipe carrying high-pressure radioactive steam.
For off-design calculations, the Stodola's cone law off-design flow rate is ˙, respectively, the temperature and pressure at the stage group intake are and and the outlet pressure is . Stodola established experimentally that the relationship between these three parameters as represented in the Cartesian coordinate system has the shape of a ...
If more than one formula is applicable in the flow regime under consideration, the choice of formula may be influenced by one or more of the following: Required accuracy; Speed of computation required; Available computational technology: calculator (minimize keystrokes) spreadsheet (single-cell formula) programming/scripting language (subroutine).
Then, for instance, to calculate the percent of the piston's stroke at which steam admission is cut off: Calculate the angle whose cosine is twice the lap divided by the valve travel; Calculate the angle whose cosine is twice the (lap plus lead), divided by the valve travel
Most charts or tables indicate the type of friction factor, or at least provide the formula for the friction factor with laminar flow. If the formula for laminar flow is f = 16 / Re , it is the Fanning factor f, and if the formula for laminar flow is f D = 64 / Re , it is the Darcy–Weisbach factor f D.