Ad
related to: control valve vs on off lever for boat lift cable lubricant
Search results
Results From The WOW.Com Content Network
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure , temperature , and liquid level.
The main valve block is usually a stack of off the shelf directional control valves chosen by flow capacity and performance. Some valves are designed to be proportional (flow rate proportional to valve position), while others may be simply on-off. The control valve is one of the most expensive and sensitive parts of a hydraulic circuit.
Here, small valves were attached to the original control cables, controlling the flow of oil into an associated actuator connected to the control surface. One of the earliest fittings of a hydraulic boost system was to ailerons on late-war models of the P-38L, removing the need for great human strength to achieve a higher rate of roll.
Simple hydraulic control valves are binary, they are either on or off. Servo valves are different in that they can continuously vary the flow they supply from zero up to their rated maximum flow, or until the output pressure reaches the supplied pressure. More complex servo valves can control other parameters.
The hydraulic actuators respond to changes of pressure or flow and will open or close the valve. Automatic control valves do not require an external power source, meaning that the fluid pressure is enough to open and close them. Flow control valves, a type of automatic control valve, regulate fluid flow by maintaining a predetermined flow rate ...
Halyards (sometimes haulyards), are used to raise sails and control luff tension. In large yachts the halyard returns to the deck but in small racing dinghies the head of the sail is attached by a short line to the head of the mast while the boat is lying on its gunwale. [1] Topping lifts, which hold booms and yards aloft. [1]
Historically, petcocks were threaded valves controlled by a butterfly handle; [citation needed] modern petcocks are typically ball valves. Compared to the progressive control of a gate valve a ball valve style petcock's is coarse, confining their use principally to on-off applications.
In general, straight-through diaphragm valves are used in on-off applications and weir-type diaphragm valves are used for control or throttling applications. While diaphragm valves usually come in two-port forms (2/2-way diaphragm valve), they can also come with three ports (3/2-way diaphragm valves also called T-valves) and more (so called ...