Pressure Regulating Valve
		A Pressure regulating valve provides a relatively constant pressure by reduces the input pressure of a fluid to a desired value at its output. Regulators are used for gases and liquids.
Introduction Air pressure which is too low is uneconomical because it results in poor efficiency.  This is why it is necessary to take pressure at the optimum operating level by means of a pressure regulating valve.  This level will depend on the type of pneumatic device used. There are two types of regulators: 1. Standard Regulators, and 2. Pilot Operated Regulators
Standard Regulator Outlet pressure is set by the adjusting screw loading the setting spring to hold the main valve open, allowing flow from the P1 inlet port to the P2 outlet port.  Outlet pressure can be balanced against the spring adjustable force using a piston or a diaphragm. Then the pressure in the circuit connected to the outlet rises and acts on the diaphragm, creating a lifting force against the spring load. If the consumption rate decreases, P2 will slightly increase; this increases tile force on the diaphragm; diaphragm elevates; and air flow decreases until it matches the consumption rate and the output pressure is maintained. If the consumption level increases, P2 will slightly decrease, force on the diaphragm decreases; diaphragm descends; and air flow increases until the consumption is balanced. With no air consumption, the valve is closed. If exit pressure rises above the set value (exit pressure is regulated at a lower level, otherwise there will be a pressure peak at the pneumatic actuator), tile diaphragm will lift to open the relieving seat so that excess pressure can be bled off through the vent hole in the regulator body. With very high flow rates, the valve is wide open.
Pilot Operated Regulator The operation is similar to a standard pressure regulator, but the pilot operated regulator offers a higher accuracy of pressure regulation. This higher accuracy is obtained by replacing the setting spring of a standard regulator with pilot pressure from a small pilot regulator sited on the unit.
Filter Regulating Unit Air filtering and pressure regulation are combined in the single filter regulator, which provides a compact space saving unit. FILTERING Atmospheric air has dust and humidity.  After the compression, humidity condenses in the after-cooler and in the air receiver, but there are always some rests, apart from oil and wear from the sealing. In order to remove these polluting agents, it is necessary to clean the air in the closest part to the operation area, that is why filters are used. There are different kinds of filters
Standard Filter The standard filter is a combined water separator and filter.  If the air has not been de-hydrated beforehand, a considerable quantity of water will be collected and the filter will hold back solid impurities as dust and rust particles. The separation of water, oil and other heavy particles occurs by a rapid rotation of the air, caused by the deflector at the inlet.  These particles crash on the wall of the filter bowl before running down to collect at the bottom.  Then they can be drained off by means of a manual or automatic drain.
Micro-Filter Micro-filters are used when contamination by oil vapour is undesirable.  The air flows from the inlet to the centre of the filter carriage ridge then outwards through the outlet.  Dust is trapped within the micro- filter element, the oil vapour and water mist is converted into liquid, falling to the bottom of the bowl induced by a coalescing action inside the filter material.
Sub- Micro Filters Sub-micro filters virtually eliminates oil, water and fine particles down to 0.01 of a micron, to provide maximum protection to pneumatic devices such as measuring devices, spray painting, electrostatic devices, cleaning and drying of electronic accessories. These filters have additional layers which provide higher filtration efficiency.
Air Quality There are 7 typical degrees of Filtration:
Typical applications for the 7 filtering levels are:
Sizing of Regulators and Filters It is important in order to get the desired flow for a particular application, with a minimum pressure variation in all the unit's flow range, depending on two factors: 1. The maximum flow used, and 2. The maximum acceptable pressure drop.
Compressed Air Lubrications Lubrication is no longer a necessity for the majority of modern Pneumatic components, most are pre-lubricated for life. This provides some advantages such as: - Savings (there is no need to purchase a lubrication device). - Cleaner and more hygienic systems. - Oil-free atmosphere for a healthier, safer working environment). Certain equipment still requires lubrication.  To ensure they are continually lubricated, a certain quantity of oil is added to the compressed air by means of a lubricator. Basically, there are four kinds of lubricators: 1. Proportional 2. Injection 3. Micro Mist 4. Centralized Systems
	Proportional Lubricators A flow- proportional pressure drop is provoked between inlet and outlet.  This makes the oil lift from the bowl into the sight feed dome.
	Injection Lubricator By a pressure signal, a piston placed in a small rod pump is activated.  This way, small quantities of oil are injected.
	Micro Mist Lubricator Oil dosed. instead of entering the air flow directly, goes through a nozzle towards the oil receiver.  This system makes that the thickest drops are held, assuring an extra- fine spraying.
	Centralized Lubrication System They make the air bubble in the oil, after provoking a pressure difference to assure the bubbling.