Hydraulic Filter

Oils, emulsions, and other hydraulic fluids are filtered using hydraulic filters. They're essential components of every hydraulic system. The goal of such a system is to use pressurised hydraulic fluid to activate a hydraulic cylinder (also known as a hydraulic motor).

A basic hydraulic system is made up of various parts:
  • A hydraulic fluid reservoir that permits power transmission to be transported via the system. Hydraulic fluids are usually made of oil or water and have little to no compressibility.
  • A filter that removes pollutants from the environment.
  • A pump is used to circulate hydraulic fluid throughout the system.
  • Fluid transfer lines (tubes, pipes, and/or hoses) to and from the hydraulic cylinder.
  • A control valve that allows the cylinder to be extended or retracted.
  • Finally, a linear motion is provided by a hydraulic cylinder.
Importance of Hydraulic Filters in a System

Modern hydraulic systems operate at higher pressures and longer cycle times, increasing the system's sensitivity to contamination as both of these characteristics grow. Fluid impurities are a common cause of hydraulic system failure and can result in a variety of issues, including:

  • Unintentional mixing of incompatible fluids, resulting in fluid breakdown and acid corrosion.
  • Internal leakage reduces component efficiency and precision (pump, motor and valve).
  • Particle accumulation in key places generates sludge, which causes parts to stick.
  • Particle accumulation in areas of low tolerance, resulting in component seizure.

Preventing contaminating particles from cycling through the system is the apparent solution to these issues. As a result, a hydraulic system's filter must be clean and efficient.

Specifications

An engineer must first determine the hydraulic system's characteristics and specifics before selecting a filter type as mentioned below. Among the important variables are:

  • Fluid flow per cycle optimal resistance of the filter quantity of contaminant the filter is expected to contain for a specified period of time
  • Hydraulic fluid type and operating pressure
  • Fluid cleanliness is excellent.

Types: Hydraulic filters are frequently categorised according to their intended use in a hydraulic system. The table below lists the various types of filters.

In-line: It might be suction side (before the pump) or pressure side (after the pump but before valves and cylinders); the inlet, output, and medium are all aligned.

Off-line: A separate pump and filter that is directly connected to the reservoir; frequently used to augment main system filters.

Tank: It may be mounted on or within the fluid reservoir, and it may have an external head for easy access and media change.

Spin-on: An in-line head is screwed onto a threaded canister; it is simple to install and cost effective.

Return line: Filter is mounted directly on the return line; alternatively, it can be spin-on, in-line, or tank-mounted.

Duplex: Actually a valve/filter combination that allows flow to two distinct filters while filter maintenance is performed.