The relief valve is a device, usually in a high-low circuit used. The circuit is sometimes referred to as a fast approach, slow feed circuit. The valve is also in a system where a large flow is needed at a lower pressure, and then used later, is a very low flow at a higher pressure is required.

Usually two pumps are plumbed in parallel used in such a circuit.
A fixed displacement pump, the volume provides for low pressure, high flow mode, while a small pump provides the low-flow with the higher pressure. Both pumps have a flow in the low-pressure, high-flow mode. The purpose of the use of two pumps draw energy from the engines to save long term, if only to maintain the function of the hydraulic system at a constant maximum pressure with little or no flow.

If the system cylinders are rapidly expanding at low pressure to send (no pressure relief valve setting), two pumps in its entirety in the cylinder.
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When the cylinder enough to encounter mechanical resistance of the system, the introduction of the relief valve under pressure to be piloted high pump flow directed into the tank through the pressure relief valve. In contrast to a pressure relief valve, reducing the pressure operated valve on the flow is minimal. Therefore, the pressure relief valve no danger to the heating problem. The volume of the smaller pump can not escape to the tank through the relief valve through the check valve in the system. The presence of the valve makes the chart symbol for relief valve differs from a typical pressure relief valve.

When the cylinder further against the resistance (system pressure) is higher than the relief valve setting, the movement is slower than the volume of the small pump to move. In many cases, the cylinder to a halt if the machine is active margins of an assembly machine or system unique. At this point, open the main valve and the maximum (or terminals) pressure. If you’re a safety valve is to be pressure compensated to a maximum pressure limitation of the smaller pump with variable displacement / strain.

In many systems, the large volume, designed to pump pump. The small pump is often used as the pump, since they often used only on a printing system to offer support if the cylinders are used in a terminal mode called. The small pump will only supply enough volume to make the cylinder for an internal leak in the system.

   The advantage of Cartridge Valve is better than conventional cemented with Subplate – mounted as follows.
   1. The design is flexible.
   2. Price of installation under
   3. Smaller.
   4. The features and better control.
   5. Secure.
   6. The pressure over
   7. The work more efficient.
   8. Can differentiate between leakage and external leakage and internal leakage.
   9. The time of each stroke is faster.
   10. Noise less than

   The primary function of that type of Cartridge Valve Slip – in.
   The work of this type of valve is similar to a Poppet check valve, which consists of the inserted pieces into a room of Manifold.

Cartrid Valve Detail

   Components of the Cartridge. Valve type that slip – in.

   To separate the major components is broken down. The valve to an external oil 2 channel is channel A and channel B will penetrate through the clot Man New workflow express the channel A and channel B to the rest of the system intended to be a channel bottleneck is to reduce speed. When the valve opens and closes, which in many sizes to choose from. Each size is associated with the work so the designer can reduce the Shock that occurs in the system to a minimum.

   Use of force and open the valve closed.
   Force for closing the valve caused the pressure acting on the AAP area, plus the force of the spring force to open the valve to the pressure. Made to the area of the box A and box B if the sum of the forces that close the valve more than the sum of the forces that open the valve. This valve will close in nature. And vice versa. If the sum of the forces that open the valve more than the sum of the forces that close the valve. Valves are open in nature.

Simple system with cartrid valve

     Example circuit.

   Figure HYDRO-CARTRIDGE-2. An example circuit for area 1: 2 and 40 pound spring force in this circuit will make oil go in Cartridge Valve cylinder through that area will notice that the AP is connected by pipes to the fuel tank through a DC power valve so that the valve is closed by spring force alone. If the pressure of the pressure cylinder was 1,000 pounds per square inch, it means that the pressure at Area A was 1,000 pounds per square inch, and area B were 1,000 pounds per square inch and the area of AP equal to zero if it is calculated that the valve closed or Open the following can be done.

   Assume that.
   AAP = 2 square inches.
   AA = 1 square inch
   AB = 1 square inch
   The valve closing force (Fc) = 40 pounds (0 pounds per square inch) = 40 lbs.
   Force the valve open (Fo) = (1,000 pounds per square inch x 1 inch) (1,000 pounds per square inch x 1 inch).
   Force the valve open (Fo) = 2,000 pounds per square inch.

   The various problems found in hydraulic a like pipe Hydrualic usually cause oil leakage at the joints various later also developed using Manifold Block to reduce the number of joints are for use to solve the problem of leakage. oil from the joints of pipe or a one.

Figure Relief valve circuit use.

We can make the system of high pressure by using pressure control valves that are normally closed position by the pressure P through the system. The oil flows through the valve to the T from the root of the fuel tank valve and spool valve working pressure within the system itself. Means when a high pressure over the valve spring force. The valve will open to the flow of oil from the root to P through T.

From these principles is the principle of Relief valve If the in Figure 59 will see that this Relief valve set pressure at 700 pounds per square inch, and when the cylinder running (ran out) the last hove Will reduce the pressure within the system increases ever finally were 700 pounds per square inch pressure of the spring was the Relief valve As a result, Relief valve opening. The oil passes through the hole to the tank P (T) when the pressure in the system remained constant at 700 pounds per square inch Relief Valve remains open at all. But whenever the pressure drop below 700 pounds per square inch Relief Valve will close.

Adjustment of the pressure (Pressure Adjustment).
The pressure control valve. A spring, which is controlled by turning the screw on the pressure valve from the outside. The valve pressure. Higher or lower depending on needs.

Use of a Normally Closed Pressure Valve

pressure control type used widely covered in Idol a waiting list. In addition to the Relief Valve is also used. Pressure control valves are also other types such as C Square Alliance Valves (Sequence valve) Counter balance valve (Counterbalance Valve) etc.

Normally Open Pressure Valve will open to this type of oil to pass out in the normal rhythm. But when there is pressure piloted into action will close the valve.

Reduce the load valve (Unloading Valve).
This type of pressure control valve is a valve that works with the external pressure (Remote Operated) The placement is off by default. When external pressure is higher than the location of this valve. It will open the valve and let oil flow into the fuel tank.

Hi – Lo System.

The valve reduces the load on the circuit that is well known. Using the integrated Hi – Lo consisting of two pumps to send the first type of fuel is very The other one was sent less oil. The purpose of this cycle in order to speed up the work, such as sending or rhythm parts to pull back so when the work runs out and then to touch the load. At this point the pressure in the system will increase. As a result, reduce the load valve open And pumps that send a large volume of oil will fuel tank through this valve reduces the load on the pump less oil to send it continues to deliver oil to the system pressure. High to work in system.

Figure Hi - Lo Circuit

Activity: For your work ,you should be make the valve disassembly, inspection, test and reassembly.

Cartridge Valves is the interior of a control valve are off the shelf components with a standard, so that they are easy to fill a block owned by the valve. They are available in different configurations, on / off, proportional, pressure relief valves, etc. Life in general in a valve block and are electrically controlled to provide logic and automated functions.
Could you see simulate thus as below.

   Have you checked the car for your tutorial system at one point or another?

   Have you ever had an industrial air hammer?

   Have you ever installed an electric bell?

     If the answer to any of these questions, then you are probably know what a solenoid valve.

hydraulic solinoid valve

Solenoid valves are electromechanical valves, by stopping or movement of electricity through a coil to be controlled to change the status of the valve. A coil is a coil of wire, the magnetic when electricity runs through them.

     Solenoid valve to activate when using this coil, the valve, thereby controlling water flow, airflow and other things with electricity.

    In general, there are three types of solenoid valves: The all-purpose type, a type of low-pressure steam and high pressure steam type.

   Solenoid valves are composed of several parts, such as wrapping, covering electrical connector nut, cartridge seal, O-ring connector end, body and nut.

  All these components are critical to the overall performance of the solenoid valves. If a malfunction, it will affect the overall operation of the automotive system for beginners as well as industrial air hammer and installation of electric bell.

   Therefore one must always be maintained and regularly inspected to

Valve Coil

 maintain the solenoid valves work best. But like all other parts of the starter system, an air hammer and an electric bell, the solenoid valve can be damaged after a certain time. Thus, solenoid valve replacement will be necessary. It? Good thing is that many dealers, the quality solenoid valves and inexpensive service. Forget when selecting valve coil, not you, check the valve type, mesh size, pressure rating, coil voltage and the type of connection to each port. Gates provides detailed information on valves, EGR valves, solenoid valves, ball valves, etc.. Valves in conjunction with copper sinks.

An altitude valve controls the level of a reservoir. The altitude valve will remain open while the tank is not full and will be closed when the reservoir reaches its maximum level. The opening and closing the valve requires no external power source (electric, pneumatic or power of man), it was done automatically, hence its name.
Control Valves
A control valve regulates the flow or fluid pressure. Control valves normally respond to signals generated by independent devices such as flow meters or temperature gauges. The control valves are normally fitted with actuators and positioners. Globe valves are widely used tire for control in many sectors, although quarter-turn types such as (amended), ball and butterfly valves are also used.
Regulation of the valves can also work with hydraulic actuators (also known as hydraulic pilots). These types of valves are also known as Automatic Control Valves. Hydraulic actuators in response to changes in pressure or flow, and open / close the valve. Valves automatiche di controllo non richiedono Sorgente di una alimentazione esterna, il che significa che la pressione del fluido è sufficiente per aprire e chiudere the valvola. Automatic control valves include: pressure reducers, valves, flow control, back support pressure valve, altitude valves and safety valves. An altitude valve controls the level of a reservoir. The altitude valve will remain open while the tank is not full and will be closed when the reservoir reaches its maximum level. The opening and closing the valve requires no external power source (electric, pneumatic or power of man), it was done automatically, hence its name.