Control valves | Hand lever valve

Manual control valves, also known as hand lever valves, are mechanical control devices that are essential for the precise control of hydraulic fluids in a system. They regulate the flow, direction, and pressure of these fluids. Their main function is to enable hydraulic actions such as moving, stopping, or positioning cylinders and motors by manually shifting a spool or piston inside the valve body.

The construction of a manual control valve includes a valve body in which a spool or piston is moved by a hand lever. The levers often have several fixed positions (e.g. neutral, working, or float position), with the neutral position often allowing pressure-free circulation of the fluid.

Typical materials:

• Valve body: cast iron or aluminum
• Spool/piston: carbonized, hard-chromed steel
• Lever: stainless steel or aluminum
• Seals: hydraulic-resistant plastics such as NBR or POM

Manual control valves are used in a wide range of applications, especially where simple, direct, and robust control without complex electronics is required:

• Agricultural and construction machinery (e.g. tractors, excavators, sweepers)
• Industrial equipment (e.g. presses, conveyor belts)
• Vehicle technology and other hydraulically controlled devices

The advantages of manual control valves include:

• Robustness and reliability even under harsh conditions
• Ease of operation without electronics and with direct feedback
• Low maintenance requirements due to solid construction and corrosion-resistant materials
• Long service life with proper use
• Cost advantages in purchase and maintenance

Important specifications for selection:

• Working pressure and nominal flow rate
• Spool configuration (e.g. 3/2, 4/2, 5/2, or 5/3 way)
• Type and number of functions
• Compatibility with screw connections and installation dimensions
• Material compatibility with hydraulic fluid
• Options such as pressure relief valves, float position, or check valves

For optimal performance and long service life, regular maintenance is required:

• Cleaning and lubrication of moving parts
• Replacement of seals
• Use of suitable filters (e.g. NAS 1638)

With proper installation and care, high-quality manual control valves achieve a service life of several years to decades, depending on operating conditions.

• Spring-centered: The lever automatically returns to the neutral position after being released.
• Detented: The lever remains in position until it is manually moved.

Pressure relief valve (PRV): Regulates the maximum working pressure (e.g. 160–315 bar) and protects the system from overload. It is usually adjustable.

A monoblock valve is a manual control valve in which all functions and sections are integrated into a single compact block housing. This simplifies installation and provides a robust design.

Available options:

• Single section
• Multiple sections (e.g. 2 or more) to control several hydraulic consumers simultaneously