Needle valves are similar in design and operation to the globe valve. Instead of a disk, a needle valve has a long tapered point at…
Month: January 2011
Globe valves are probably the most common valves in existence. The globe valve gets its name from the globular shape of the valve body. Other…
Gate valves are used when a straight-line flow of fluid and minimum flow restriction are needed. Gate valves are so-named because the part that either…
Ball valves, as the name implies, are stop valves that use a ball to stop or start a flow of fluid. The ball, shown in…
Figure 6-25, diagrams A and B respectively, shows a road-patrol truck’s hydraulic system and a hydraulic circuit’s schematic, as a comparison. The truck needs three…
Hydraulic power steering incorporates a hydraulic boost into a basic manual-steering system. A basic manual-steering system is an arrangement of gears in a box that…
Figure 6-21 shows the lift portion of the hydraulic system. The circuit has two cylinders: a single-acting lift cylinder and a double-acting tilt cylinder. The…
Listed below are areas that you can diagnose in hydraulic valves. When working on a specific machine, refer to a machine’s technical manual for more…
Since a flow-control valve meters flow in one direction only, the inlet and outlet ports must be correctly connected in a circuit in relation to…
Flow-control valves are used to control an actuator’s speed by metering flow. Metering is measuring or regulating the flow rate to or from an actuator.…