Hydraulic Tube Fittings Deliver Leak-Free Performance and Long Life

Tube Fittings for Today’s Hydraulics The latest fluid connectors deliver leak-free performance and long life despite shock, vibration, and extreme pressures. • 37° flare fittings are the most widely used, but they're not always the best choice. • Fitting and ports with elastomeric seals withstand high pressure, severe shock, and vibration. Tube fittings are essential to hydraulic systems, connecting tubing and hose to pumps, valves, cylinders, and other components. Modern connectors deliver years of leak-free performance despite high operating pressures, pressure spikes, corrosion, vibration, and other abuse. And they come in a near-endless variety of sizes, shapes, and styles to suit most any application. Here are some key considerations to match a fitting to the job. Selecting the proper fitting for a given application is an important part of system design. This selection process is driven by the following fluid system parameters: size, temperature, application, media, and pressure, often referred to as the acronym STAMP. Consider the tube outside diameter (OD) and wall thickness for all tube fittings. Most types are limited due to tube wall thickness. Flare-type fittings typically have a maximum tube-wall limitation, while flareless bite-type fittings have minimum wall limitations. Select tube OD and wall thickness based on pressure, flow rate, temperature, and other ambient conditions. Temperature range for fittings depends on material, plating, and type of seal. The accompanying table lists temperature ranges for the most common fitting and seal materials. System environment obviously influences fitting selection. Steel fittings usually have protective coatings to resist corrosion. For more-corrosive environments, stainless steel and brass are viable options. Also consider the severity of the application, such as whether operating conditions are static or dynamic, and potential consequences of failure when selecting fittings. The fluid media must be considered when selecting fitting and seal materials.