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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 hydraulic diameter, D H, is a commonly used term when handling flow in non-circular tubes and channels. Using this term, one can calculate many things in the same way as for a round tube. When the cross-section is uniform along the tube or channel length, it is defined as [1] [2] =, where
In offshore applications, huge lengths of rope are often housed on drums. The anchor winches on Saipem's Semac 1 pipe laying barge, for example, each hold 2,800 metres of 76mm (3 inch) diameter wire rope in 14 layers. Saipem's Castorone, the world's largest pipe laying vessel uses a wire rope that is 3,850m long and 152mm in diameter. It weighs ...
The spool has a central (neutral) position maintained with springs; in this position the supply fluid is blocked, or returned to tank. Sliding the spool to one side routes the hydraulic fluid to an actuator and provides a return path from the actuator to tank. When the spool is moved to the opposite direction the supply and return paths are ...
Detonating cord is also employed directly in building demolition where thin concrete slabs need be broken via channels drilled parallel to the surface, an advantage over dynamite since a lower minimum of explosive force may be used and smaller diameter holes are sufficient to contain the explosive. [2]
The JT8D is an axial-flow front turbofan engine incorporating a two-spool design. There are two coaxially-mounted independent rotating assemblies: one rotating assembly for the low pressure compressor (LPC) which consists of the first six stages (i.e. six pairs of rotating and stator blades, including the first two stages which are for the bypass turbofan), driven by the second (downstream ...
For oilfield work, the wireline resides on the surface, wound around a large (3 to 10 feet in diameter) spool. Operators may use a portable spool (on the back of a special truck) or a permanent part of the drilling rig. A motor and drive train turn the spool and raise and lower the equipment into and out of the well – the winch.
These effects are caused by the sluggish response of the spool (i.e. inertia effects) to rapid changes in engine fuel flow. Compressor surge is a particular problem during slam-accelerations and can be overcome by suitable adjustments to the fueling schedule and/or use of blow-off (bleeding air off the compressor, for handling purposes).