Category: Hydraulics & Pneumatics

In Bladder Accumulator a gas charged bag/bladder is fixed in a shell of accumulator. When pressurised oil enters into accumulator, the gas bag compresses. When system requires oil under pressure, the oil goes out and bladder expands. Continue reading What is Bladder Accumulator? Construction, Diagram, Working & Advantages

The hydraulic accumulator stores excess hydraulic energy and on demand makes the stored energy available to the system. The function of accumulator is similar to the function of flywheel in the IC engine/steam engine or capacitor in the electric circuit. Since accumulators are having the ability to store excess energy and also having ability to release the energy to system when system is in bad need of energy, the hydraulic systems using accumulators are most efficient systems because there is very little energy loss. Continue reading What is Hydraulic Accumulator? Types, Symbol, Construction, Diagram & Working

Figure 1: Double Acting Hydraulic Cylinder.

In double acting Hydraulic cylinder, the pressurized liquid is admitted on both sides of the piston alternately. Work is performed during forward motion as well as backward motion of the piston (see Fig. 1). Double acting Hydraulic cylinders are most commonly used hydraulic cylinders in industrial applications. In these cylinders, the pressure is applied on both end ports to obtain power in both directions. They are also termed differential cylinders, as they have different extension and retraction areas. Continue reading What is Double Acting Hydraulic Cylinder? Construction, Diagram & Working

In a centrifugal pump, the fluid is rotated with high speed, to rise beyond the restricted walls of the casing by means of centrifugal action of impeller. Then the liquid flow out. Continue reading What is Centrifugal Pump? Working, Parts, Diagram & Types

Hydraulic dynamometer is an absorption type of dynamometer. This dynamometer uses fluid friction for their operation i.e., to dissipate mechanical energy. Therefore, it is also known as fluid friction dynamometer. Continue reading What is Hydraulic Dynamometer? Working, Diagram, Construction & Advantages

Unloading valves are pressure control valves, used to discharge the excess fluid from the pump to the tank with a small or zero pressure drop. These valves are used in high-low pump circuit applications where two pumps are used to move an actuator at high speed and low pressure. Continue reading What is Unloading Valve? Types, Working, Construction & Diagram

Pressure sequence valve is a type of pressure control valve that is used in the applications where the two hydraulic cylinders are operating in a sequence, to allow the fluid flow to those cylinders in a pre-determined sequence. Continue reading What is Pressure Sequence Valve? Working, Construction & Diagram

Compound pressure relief valve also performs the same function as the simple pressure relief valve but it is pilot operated and is used to accommodate the high pressure and high flow capacities. Continue reading What is Compound Pressure Relief Valve? Working, Construction & Diagram

A direction control valve which has ability of infinite positioning and regulates the flow quantity, speed of motor is called servo valve. Mostly hydro electric servo systems employ servo valves for higher efficiency, response time and compactness. These valves are connected to feedback sensors to control the actuator’s position, velocity and acceleration very precisely.

Types of Servo Valve

It is classified into two types.

1. Electro hydraulic servo valve.
2. Mechanical hydraulic servo valve.

Electro hydraulic servo valve

Electro hydraulic Servo valves can be single stage or multistage, where the movement of valve spool is proportional to the input electric signal. The figure 1 below shows the multistage hydro electric servo valve which mainly consists of torque motor, double nozzle and a spool. Continue reading What is Servo Valve? Types, Working, Construction, Diagram & Applications

Internal gear pump differ from external gear pump in the arrangement of gears. An internal gear pump also consists of two gears, but one of the gear is internal gear and the other is commonly used spur gear. Both the gears rotate in the same direction. Continue reading What is Internal Gear Pump? Working, Diagram & Advantages