WU LEEMIN Oil Suction Filter

Product introduction

The WU/XU Series Suction Filters are installed on the suction line of hydraulic pumps, 

positioned between the reservoir and the pump inlet. This installation configuration requires

 the filter to offer high flow capacity with minimal pressure drop. Accordingly, 

these are coarse filters with relatively low filtration precision, specifically designed to protect

 the hydraulic pump from contaminants that may be drawn from the tank.

The series includes both WU (standard) and XU (with differential pressure indicator) models, 

offering flexible options for various hydraulic system requirements.

Key Features

1. Pump Protection – Effectively prevents contaminants and particles suspended in the tank oil from 

entering and damaging the hydraulic pump.

2. Visual Clogging Indication – Since the suction filter is installed externally to the oil tank, 

the integrated indicator provides clear visual confirmation when filter element replacement is required.

3. Tool-Free Maintenance – The filter element can be serviced or replaced without dismantling the suction 

pipe or removing the tank cover, significantly reducing maintenance downtime and labor.

4. High Flow Capacity – Designed with large filtration area to accommodate high flow rates while 

maintaining low resistance, ensuring adequate pump suction performance.

5. Durable Metal Mesh Media – Constructed with corrosion-resistant metal mesh that withstands 

repeated cleaning and provides reliable long-term service.

Product Specifications

Parameter Specification

Model WU / XU Series

Filter media Metal mesh (corrosion-resistant)

Filtration precision 80–180 μm

Nominal pressure 0.6 MPa

Nominal flow rate 16–1,000 L/min (wide range for various system sizes)

Installation location Suction line (external to oil tank)

Application field Hydraulic station lubrication systems, pump protection

Applications

1. Metallurgical Industry – Filtration for hydraulic systems of rolling mills, continuous casting machines, 

and various lubrication equipment in steel and metal processing plants.

2. Petrochemical Industry – Separation and recovery of products and intermediate products during 

refining and chemical production processes.

3. Power Generation – Oil purification for gas turbine lubrication systems, boiler lubrication, 

speed control systems, and bypass control systems in thermal and nuclear power plants.

4. General Hydraulic Systems – Suction line protection for hydraulic power units, machine tool hydraulics,

 and mobile equipment hydraulic systems.

FAQ 

Q1: What is the difference between WU and XU series models?

A: The WU series is the standard suction filter model. The XU series includes an integrated differential

 pressure indicator that provides visual warning when the filter element becomes clogged, enabling timely maintenance.

Q2: What filtration precision does this filter provide?

A: The WU/XU series offers filtration precision ranging from 80μm to 180μm, depending on the selected metal mesh grade. 

This is classified as coarse filtration, specifically designed for pump inlet protection where low

 resistance is the primary requirement.

Q3: Why is a coarse filter used on the suction line rather than a fine filter?

A: Suction line filters must have very low pressure drop to prevent pump cavitation. 

Fine filters would create excessive resistance, restricting oil flow to the pump. 

The suction filter serves as a primary protective barrier, with finer filtration typically handled downstream in

 the pressure or return lines.

Q4: Can the filter element be cleaned and reused?

A: Yes. The metal mesh filter element is washable and reusable. It can be removed, cleaned with appropriate solvent, 

and reinstalled. However, we recommend replacing the element if it shows signs of damage, corrosion, 

or if cleaning does not restore adequate flow.

Q5: How can I tell when the filter element needs servicing?

A: For XU models, the differential pressure indicator will show a visual signal when the element becomes clogged. 

For WU models, we recommend monitoring pump inlet pressure or establishing a regular maintenance

 schedule based on operating hours. A noticeable increase in pump noise or reduced system 

performance may also indicate filter clogging.

Q6: What is the maximum operating pressure for this filter?

A: The nominal pressure rating is 0.6 MPa (6 bar). As a suction-side filter, it operates under negative

 pressure (vacuum) conditions. Excessive vacuum caused by severe clogging can damage the filter 

and cause pump cavitation.

Q7: What types of hydraulic fluids are compatible?

A: The metal mesh media and housing materials are compatible with most mineral-based hydraulic oils,

 synthetic hydraulic fluids, and lubricating oils. For water-based or aggressive fluids, please consult our

 technical team for material compatibility verification.

Q8: Is the filter suitable for continuous operation?

A: Yes, the WU/XU series is designed for continuous operation in industrial hydraulic systems. 

Regular inspection and timely element cleaning or replacement are essential to maintain system reliability.

Q9: Can I install this filter on the return line instead of the suction line?

A: The WU/XU series is specifically designed for suction line installation with low-pressure drop characteristics. 

For return line filtration, we offer dedicated return-line filters. Please consult our product catalog for the appropriate solution.

Q10: Do you offer custom flow ratings or connection sizes?

A: Yes, we offer a wide flow range from 16 to 1,000 L/min with various connection sizes. 

Please contact our technical sales team with your specific requirements for customized solutions.

Product Details