Slide Valve


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slide valve

[′slīd ‚valv]
(mechanical engineering)
A sliding mechanism to cover and uncover ports for the admission of fluid, as in some steam engines.

Slide Valve

 

a movable element in a system for controlling a thermal or mechanical process; directs the flow of a working fluid or gas into the proper channel by displacement relative to ports in the surface over which it slides. Slide valves are used in piston steam engines, where they distribute the steam; in control systems for regulating steam turbines; in pneumatic mechanisms; and hydro-automated systems.

A D-slide valve is an inverted box that is alternately displaced by the slide valve rod to the right or left along the valve seat, which has rectangular ports. Depending on the position of the slide valve, the ports communicate with a closed space, which surrounds the valve and is filled with the working body, or with a cavity that is connected to the atmosphere or a condenser. A shortcoming of a D-slide valve is an imbalance, as a result of which the working body presses the valve strongly against the seat, causing wear of the working surfaces and necessitating considerable force to move the valve.

A piston valve is similar to a D-slide valve in its principle of operation but is completely balanced. Such a slide valve has two pistons that are mounted on a common stem and move in a bushing equipped with ports. In high-precision hydraulic control systems piston valves are sometimes given a continuous rotary motion about their axis or an oscillatory motion along the axis to increase the system’s sensitivity by substituting friction of motion for static friction.

A tap valve is essentially a D-slide valve bent around its axis, which is perpendicular to the direction of its movement. The valve is set into a cylindrical bushing with two ports. As it rocks around its fixed axis, the valve connects or disconnects the ports and chambers.

The one-way air valve of an automobile tire is also called a slide valve.

REFERENCES

Lemberg,M. D. Sistemy gidroavtomatiki. Moscow-Leningrad, 1965.
Veller, V. N. Avtomaticheskoe regulirovanie parovykh turbin. Moscow, 1967.

S. M. LOSEV

References in periodicals archive ?
There is a relationship between the capacity of a screw compressor and its slide valve position but this relationship is non-linear as shown in Figure 2.
I was soon shocked to find out that the mesh screen was supposed to be inside the fuel line that attaches to the slide valve, to prevent debris from contaminating the fuel system during in flight refueling.
A major Houston-based manufacturer of slide valves, Tapco International, came up with a design that would eliminate bolts to make the valve last longer.
Four different filling technologies are available, depending upon the product characteristics: Smart Fill time/pressure filling, rolling diaphragm pumps, rotary slide valve pumps, and a filling station with mass flow measurement.
Environmental Affairs Manager Lisa Swanson added: "Recent projects to reduce air emissions include a new generator and turbocharger retrofits on our C9-class vessels, a slide valve retrofit on the MV R.
The vertical slide valve function is visually easy to identify and understand the How state, it saves space and provides simple padlock lock-off for ensured isolation during maintenance or to prevent unnecessary activation and wastage during stand down periods.
With screw compressors, it is possible to eliminate the slide valve, using speed variation to cover the full operating range at higher efficiency.
Tenders are invited for Apgenco-srb-supply of main slide valve for disc valve pressure lines pertaining to srisailam right bank.
A slide valve or a volumetric star feeder doses the individual components into a container with a scale.
A capacity control slide valve provides for infinite capacity control from 10% to 100% without hot gas bypass control.
Tenders are invited for Procurement of regen and spent slide valve filters
The screw compressor can operate at speeds between 1500 and 3600 rpm at 100 percent slide valve position.