In hydraulic systems, the presence of solid contaminants—ranging from visible to invisible to the naked eye—in process fluid can severely affect the structural integrity and performance of the system. The particulate matter can interfere with normal fluid flow, allow incompatible materials to mix, and/or cause premature wear (and, ultimately, failure). Avoiding these issues necessitates integrating hydraulic filters and strainers, which capture solid material before it becomes problematic.

For over 60 years, DOMS Incorporated has served as a premier manufacturer of hydraulic system components, including suction filters, suction strainers, reservoir breather filters, and spin-on filters. Given their critical function, we design and construct all of our products for reliable operation even in the most demanding hydraulic environments.

Hydraulic Filters and Strainers From DOMS Incorporated

At DOMS Incorporated, we offer an extensive selection of products for hydraulic systems, including the following:

Suction Filters

Suction filters are designed to remove fine contaminants from the suction line of a hydraulic system. Their porous filtration media captures solid particulates and pollutants that are less than 50 microns in size. They are suitable for use in hydraulic systems with positive pressure and constant flow and generally integrated into the return line.

Our suction filters feature an innovative rounded root and crest pleat design that maximizes filter area utilization for effective long-term performance. They come in models with capacity ratings ranging from 5–200 GPM. Variations with and without relief valves are available.

Suction Strainers

Suction strainers operate similarly to suction filters but are better suited for capturing large particulate matter equal to or greater than 50 microns in size. They are suitable for use in the suction lines of hydraulic systems.

Our suction strainers are also designed to maximize the utilization of the straining area. As they are less flow restrictive than suction filters, they are less susceptible to increases in suction pressure that can cause cavitation within the pump component. However, regular removal of contamination buildup ensures the above problems do not occur. They come in models with capacity ratings ranging from 5–200 GPM. Variations with and without relief valves are available.

Spin-On Filters

Spin-on filters are designed for direct in-line mounting with the piping in hydraulic systems. Their design facilitates installation and replacement, reducing housekeeping requirements. They are an effective and economical filtration solution for low-pressure systems—such as compressors, cooling circuits, fuel transfer lines, hydrostatic charge pumps, lube oil systems, and power transmission systems—that are not at risk of high-pressure surges.

Our spin-on filters employ several types of media—i.e., cellulose media, synthetic media, stainless steel wire mesh, and water-absorption elements—to accommodate the filtration needs of different applications. They are available in single and dual spin-on head variations with or without bypass valves.

Reservoir Breather Filters

Reservoir breather filters remove contaminants from the air entering the hydraulic systems’ tank. Ours come in the following variations: risers, dipsticks, spin-on breathers, and threaded breathers. They are available with cast aluminum cap or nylon construction and with or without pressure valves.

What Are Hydraulic Filters and Strainers?

Suction Filters and StrainersContaminants can enter even the most well-designed hydraulic systems, particularly during maintenance operations or through worn seals. For this reason, most hydraulic systems integrate some form of filtration unit.

Hydraulic filters and strainers are designed to remove solid foreign matter from emulsions, oils, and other process fluids before it cycles through a hydraulic system. They are generally positioned right before or within the system’s reservoir to remove any contaminants introduced during the previous cycle before the fluid enters the next cycle.

While filters and strainers perform similar functions, they are employed for different use cases. Filters are used to remove contaminants that are smaller than 50 microns, while strainers are used to remove contaminants that are 50 microns or greater. Both are available with options for various construction materials, mesh sizes, and performance ratings to suit the requirements and restrictions of different hydraulic systems.

The Importance of Filtration Units in Hydraulic Systems

The high operating pressures and speeds characteristic of modern hydraulic systems make them more susceptible to damage from fluid contamination. Some of the problems that may arise due to the presence of unwanted solid matter in process fluid include:

  • Unintended interaction between incompatible fluids, which can lead to fluid degradation and acid corrosion
  • Internal leakage, which can lead to decreased system performance
  • Particle accumulation at key points in the system, which can lead to sticking, stalling, and component failure

For the above reasons, among others, the integration of appropriate filters and/or strainers is essential to ensuring a hydraulic system continues to run as intended.

Selection Considerations for Hydraulic Filters and Strainers

Hydraulic systems are subjected to different operational and environmental conditions, depending on their exact application. As a result, the ideal hydraulic filter or strainer varies from one system to the next. When choosing one for a particular hydraulic system, some of the factors to consider to ensure the selected component demonstrates the correct performance characteristics include:

  • Type of process fluid(s)
  • Operating pressures
  • Operating temperatures
  • Fluid flow per cycle
  • Filter resistance requirements
  • Filtration efficiency requirements
  • Type and estimated volume of contaminants

Products for Heavy Machinery

In addition to our hydraulic filters and strainers, we offer several other products for use in heavy machinery, including:

  • Diffusers: Diffusers are used to reduce foam buildup as process fluid moves throughout the system. They are typically employed alongside a suction filter, which removes particulate matter before the fluid flows through the diffuser into the reservoir. They are available in several standard sizes, mesh filter sizes, and GPM ratings. For customers with highly specific needs, we can modify the design to accommodate their specifications.
  • Air Filters: Air filters help boost the quality of air in systems, such as motors and air compressors. Ours are designed for a high degree of air permeability to prevent pressure differentials and contamination buildup. They are available with synthetic or stainless steel construction.
  • Pressure and Sight Gauges: Sight gauges facilitate the monitoring of fluid levels in hydraulic systems. We offer sight gauges suitable for use in low-pressure applications.

For additional information about our hydraulic filters and strainers or other products, contact us or request a quote today.