can you suggest me where can i get the details of different kinds of valves used in hydraulic systems.?

Question

valves like
butterfly valve,non return valve,ball valve,globe valve, gate valve,etc:- what are the best conditions for the different usage of these valves.where can each valve be better used.can we control the pressure of the hydraulic line with any valve?

Answer 1

*Hydraulic valves:

control and direct the oil from the time it leaves , the pump until it starts on its return to the reservoir in a hydraulic circuit. The relief valve is almost always the first one encountered by the oil after it leaves the pump. From that point on throughout the circuit, the type of valve employed depends upon the design of the circuit. In a very simple circuit the second and only other valve used will probably be the master control valve. In a complex circuit the oil may flow through a sequence valve, master control valve, reducing valve, flow control valve, check valve and several others before it finally returns to the reservoir.



Hydraulic valves as used in industrial applications are built in several pressure ranges. The majority of present applications are in the range of 0 to 1500 lb per sq in., but the trend is toward higher pressures. Various types of valves are used in hydraulic systems to control or regulate the flow medium. Basically valves are expected to control:



* Blocking or stopping of flow

* Direction of flow

* Pressure of flow media

* Flow quantity





*A pressure control valve performs the following functions:



* Limiting maximum system pressure as a safety measure

* Regulating/reducing pressure in certain portions of the circuit

* Unloading system pressure

* Assisting sequential operation of actuators in a circuit with pressure control

* Any other pressure related function by virtue of pressure control



Pressure control valves are used to control and regulate pressure in fluid power systems. They are often globe-shaped and designed with flanged ends to allow for ease of maintenance. The valve is smaller than the line in which it is attached. This design feature prevents the valve from throttling, which would cause the seat to wear too quickly. In hydraulic systems pressure regulators are used to unload the system and to maintain and regulate pressure at the desired values.



Types of Pressure Control Valves

Pressure Regulators- Pressure regulators keep the output pressure at a set value. Pressure regulators control pressure in lines (usually adjustable) to remove fluctuations and maintain consistent pressure.



Counter-Balance Valves- Counter-balance valves, also called load holding valves or over-center valves, are normally located between a directional control valve and the outlet of a vertically mounted actuating cylinder that must support weight or be held in position for a period of time. The counter-balance valve serves as hydraulic resistance to the actuating cylinder.



Sequence Valves- Sequence valves control the sequence of operation between two branches of a circuit. They enable one unit to automatically set another unit into motion.



Uploading Valves- The main application of an unloading valve is to unload a pump and save energy when the flow is not required. There are both hydraulic and pneumatic applications. Pressure control valves can handle a wide range of media including air and gaseous materials; fuel, gas and oil; liquids, steam and hydraulic fluids.



:::: For classification and application of valves , please click on the following link:

http://www.engineeringtoolbox.com/valves-types-d_218.html

Answer 2

The biggest advantage is the amount of power in a given space. Hyd systems typically operate at 2000psi and up, compared to about 80psi for pneumatic. Also, since fluid is non compressible, the moement distance can be linear. Many aircraft, and industrial equipment now use electric servos instead of hydraulics. Biggest problem with hydraulics is leaks. 2nd biggest problem is continuous power consumption to the pump. Lots of air power is used in industry, so it is the easiest way to move or clamp anything, with nothing more than an air cylinder and a valve. Each system has it's place to do different things.

Answer 3

For other uses, see Valve (disambiguation). For the electronic component, see Thermionic valve. For the game development company see Valve Corporation.



These water valves are operated by handles.



A valve is a device that regulates the flow of a fluid (gases, fluidized solids, slurries, or liquids) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed separately.



Valves are also found in the human body. For example there are several which control the flow of blood in the chambers of the heart and maintain the correct pumping action (see heart valve article).



Valves are used in a variety of applications including industrial, military, commercial, residential, and transportation.



Oil and gas, power generation, mining, water reticulation, sewerage and chemical manufacturing would constitute the majority of valves used by industry.



Plumbing valves are the most obvious in everyday life, taps for hot and cold water, gas control valves on cookers and barbecues, small valves fitted to washing machines and dishwashers, and safety devices fitted to hot water systems are all examples of valves.



Valves may be operated manually, either by a hand wheel, lever or pedal. Valves may also be automatic, driven by changes in pressure, temperature or flow. These changes may act upon a diaphram or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or steam boilers.



More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator. An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.



Valves are also found in the Otto cycle (internal combustion) engines driven by a camshaft, lifters and or push rods where they play a major role in engine cycle control.

Answer 4

u shld search in google ,, just search with all those names or valves u will get all information..