The Use of Hydraulic Fittings
August 3rd, 2022
Hydraulic fittings connect conductors such as hoses, pipes, and tubes in hydraulic systems. Most fittings have male and female components that connect to form the connection. These connections help control and direct the flow of hydraulic fluid in the conductors while preventing leaks and maintaining pressure. Different accessories allow designers to change the flow direction, line height or diversion. Crimping is the most common method of assembling hoses and fittings. Once the crimp specification for a particular hose and fitting has been checked, the crimper is adjusted to the appropriate crimp diameter setting. The next step is to lubricate the fitting, place it on the end of the hose, and place it in the crimper.
Some hydraulic fitting manufacturers offer a no-skin option on their hoses. Scraping is the process of removing part of the hose cap or even the inner tube before connecting the hose ends. This step is not required for unskinned hoses. Many people prefer the no-skin option because it assembles the hose faster and reduces the risk of hose damage during the crimping process.
Fitting geometries include crosses, plugs, elbows, etc. It is important to note this when identifying connected threads. Often, a connection from one standard appears to pass through another standard port, but there isn't enough engagement to be safe. Also, most fittings are brand specific to some hoses and may not work with other brands. While fitting sizes generally correspond to conductor sizes, there may still be differences in fitting options for one size of pipe or tubing.
Accessories are made from many different materials, including stainless steel, brass, plastic, monel, and more. Not always, but usually the fittings match the conductor material used in the system. Multiple materials create accessories with a wide range of performance capabilities. Most hydraulic fittings have specified pressure and temperature ratings as well as size and dimension standards set by SAE.