We now offer you an expanded line of accessories for hydraulic lines and reservoirs! Finish off your hydraulic circuit with filter service indicators, pressure gauges, test points assemblies, valves, flanges, reservoir level gauges, sight glasses, a variety of tank and filler breathers, caps, vents, plugs, strainers, diffusers, magnets and more.

T.R.A.P. Breathers – NEW Technology!

T.R.A.P. BreathersKeep moisture and dirt OUT of your hydraulic reservoir with Donaldson’s innovative new technology, the Thermally Reactive Advanced Protection (T.R.A.P.™) breather! It senses moisture and begins working faster and lasts longer than desiccant breathers. This is an entirely new technology that provides better protection for your oil or hydraulic fluid.
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Pressure Gauges

Pressure GaugesMechanical bourdon tube pressure gauges with glycerin-filled stainless steel bezels and cases in a variety of face diameters are easy to install for continual monitoring of system pressure.
Pressure Gauge Specs


ValvesIn-line check valves to 200 gpm flow, ball valves for low, medium and high pressure (up to 7250 psi), two-way and three-way, standard and T-handle styles, also split flange ball valves.
Valve Specs

Strainers & Diffusers

Strainers & DiffusersStrainers remove larger particulate from the fluid in your reservoir or sump. Diffusers reduce aeration, foaming, turbulence and noise caused by return lines.
Strainer Specs

Sight Glasses

Sight GlassesLeak-free sight glasses come in plastic or metal for use with a variety of fluids. Steel models work well in high pressure and high temperature applications. In areas of low light, prism lens sight glasses provide quick, accurate readings.
Sight Glass Specs

Reservoir Magnets

Reservoir MagnetsTrap and hold ferrous metal contaminants, typically located in the tank. If not contained, these contaminants will cause collateral damage to significant components!
Reservoir Magnet Specs

Suction & Return Flanges, Weld Risers

Suction & Return Flanges, Weld RisersThese flanges are designed for tank top mounting and provide a seal to the pipe and reservoir without welding.
Flange & Weld Riser Specs

Filter Service Indicators

Filter Service IndicatorsService indicators — electrical, visual, pressure, or differential – tell you when to change the filter. Mount on the filter head or connect remotely to your central control panel.
Indicator Specs.

Test Points

Test PointsTest points can be used as a connection into the hydraulic system on the suction side, pressure side or return. They allow connection for pressure and temperature transducers and provide ports for fluid sampling so you can monitor system cleanliness. Assemblies, adapters and hoses allow access to hard-to-reach lines.
Test Point Specs.

Port Flanges

Port FlangesFor connecting components on a hydraulic line we offer split flanges, gage port spacers, elbow flanges, blanking flanges, 4-bolt NPTF and SAE threaded flanges, flat socket weld and butt weld flanges in a broad range of sizes. O-Ring and flat face models, Schedule 61 and 62 options.
Port Flange Specs


BreathersAvailable in a wide range of styles, materials and sizes. Breathers provide clean airflow into reservoirs and other storage devices where there is an exchange of air during changing fluid levels. Breather caps with pressure relief and vacuum breakers limit air exchange and provide a positive suction at the pump inlet. Styles include spin-on, filler breathers, bayonet style with dip stick options, pressure filler breather caps and more. Prevent airborne contaminant from entering the tank!
Breather Specs

Fluid Level Gauges

Fluid Level GaugesGauges that show the oil level, or the oil level AND oil temperature. Steel and polyamide options. Models suitable for pressurized reservoirs.
Fluid Level Gauge Specs

Caps, Plugs & Vents

Caps, Plugs & VentsDonaldson’s range of plastic plugs, caps and vents are a rare find! They’re great for small power units and gearboxes.
Reservoir Magnet Specs