Directly operated relief valve

Pressure Control Valves
Pressure control valves can be divide into Relief Valves,Pressure Reducing Valves,Sequence Valves.

[Cartridge Relief Valves]
A Relief valve is a type of valve used on a liquid service, which relieves pressure proportionally (slowly) as the increasing pressure overcomes the spring pressure. The pressure is relieved by allowing the pressurized fluid to flow from an auxiliary passage out of the system. The relief valve is designed or set to open at a predetermined pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits. When the pressure setting is exceeded, the relief valve becomes the "path of least resistance" as the valve is forced open and a portion of the fluid is diverted through the auxiliary route. The diverted fluid is usually routed through a piping system known as a flare header or relief header to a central. As the fluid is diverted, the pressure inside the vessel will drop. Once it reaches the valve's re-seating pressure, the valve will re-close. This pressure, also called blow down, is usually within several percent of the set-pressure.
In some cases, a so-called bypass valve acts as a relief valve by being used to return all or part of the fluid discharged by a pump back to either a storage reservoir or the inlet of the pump. This is done to protect the pump and any associated equipment from excessive pressure.

[Pressure Reducing Valves]
Reduce the supply pressure as needed for various circuits.

[Cartridge Sequence Valves]
Control the sequence of hydraulic circuits; to insure that one hydraulic cylinder is fully extended before another starts its stroke

Features:
1.Light weight and compact size
-Combining several functions into a single manifold may save valuable space and weight, often occupying only 10% to 20% as much volume as conventional line-mounted systems plumbed with fittings, hose, and tubing.

2.Leakage prevention
-Because a valve package eliminates so many connections, system leakage potential is reduced drastically.

3.Efficiency for the system
-Valve packages that eliminate interconnecting lines and fittings lead to higher overall system efficiencies

4. Convenience and Serviceability
-Being more compact, valve packages sometimes can be mounted where they are less susceptible to external damage.
-Cartridges usually can be removed and replaced quickly without disturbing any external plumbing.

5. Aesthetics and Economy
-A clean design will not affect performance, but a good-looking machine on the dealer's sales floor in a competitive market can be an advantage to the OEM.
-On many systems, the cost of a custom valve package ,can be equal to (or less than) that of a system with individually plumbed components