Contamination Control in Hydraulic Systems

Product | 15 Jan 2019

Around 75% of all system failures can be attributed to the contamination in the hydraulic system besides human error. As such, proper filtration and monitoring has always played an exemplary role in keeping the hydraulic system intact. Without enough preventive actions to stop fluid contamination, negative effects can escalate to the point of component failure, causing downtime. This downtime and loss of production are directly responsible for a company’s lost revenue. Eliminating contamination thus becomes an integral function of managing a hydraulic system.

Role of Fluids in a Hydraulic System

The fluid performs four basic functions in a hydraulic system:
1. It creates force and motion as the fluid flow is converted into pressure.

2. By occupying the space between metal surfaces, the fluid forms a seal providing a pressure barrier while excluding contaminants.

3. It provides lubrication to the metal surfaces.

4. Cools down system components.

There are a number of fluid options available from mineral oils to water based fluids to eco-friendly fluids. The fluids vary in their features of viscosity, lubricant capacity, anti-wear protection, density, resistance to ageing, materials compatibility etc.

Reasons for Contamination of Fluids

Contamination of fluids is commonly caused by dust, dirt and sludge. The fluid passes through and touches various components inside the hydraulic system where it picks up additional impurities caused by the wear off of the components, abrasion, leakage of seals etc. Contaminants can also enter through breather caps, imperfect seals and other openings.

What is Hydraulic Filtration?

All the hydraulic fluids have a certain level of contamination already present in them which concentrates even more once they enter the system and pass through its various components. Hydraulic filtration is the process of separation of contamination from the hydraulic oil. Hydraulic Filter is a component of the Hydraulic System, incorporated to maintain fluid cleanliness as per design needs.

Depending on their location in the system, the filters are classified into 3 types
1. Suction Strainer/Filter
2. Return Line Filter
3. Pressure-line Filter

Suction filter is located on a suction port of the pump or submerged in the reservoir and attached to the suction line leading to the pump. High-efficiency filters are usually prohibited in the suction side as high differential pressure can cause pump failure. These filters usually consist of metal wire mesh and must be selected properly to avoid any possible pump cavitation.

Return line filters are designed to be installed in-line or mount directly onto the tank cover. The filter collects all flow from the system and filters the oil before it returns to the tank. Such an arrangement ensures that the oil in the reservoir will be cleaned to the desired ISO specification.

Pressure Line filters are located on the pressure line, directly protecting one or more components e.g. proportional valves and servo valves. This filter is generally installed between the pump outlet and the rest of the components in a hydraulic system. They usually have filter elements made of glass fiber.

Fleetguard, one of the best filter manufacturers in India, develops and manufactures a wide range of hydraulic filters. They offer filters required for troubleshooting and addressing the performance demands of any hydraulic system. Fleetguard product range includes filter housings, filter heads, replacement cartridges, spin-on head & assemblies, catering to high, medium and low-pressure hydraulic systems thereby protecting industrial machinery, components and heavy-duty–mobile equipments.