What’s ORB Fittings?
Commonly known as O-ring boss (ORB) fittings, these components are defined by the SAE J1926 standard. This standard specifies the dimensions for both the male and female parts.
The male part features threads according to the Unified Thread Standard (UNF/ASME B 1.1) and includes a groove for an O-ring. The female part has a seat or chamfer where the threads begin. When the male and female parts are connected, the rubber-like O-ring is compressed between the two seats, creating an extremely tight seal that compensates for dimensional variations.
Due to the variety of standards used for fluid conveyance worldwide, you might need a fitting with ORB connections on one end and NPT, NPS, AN, or JIS connections on the other. These fittings are typically made from high-strength carbon or stainless steel to withstand the high-pressure applications they are designed for.
ORB Thread Size Chart
Advantages of ORB Fittings
ORB fittings offer several advantages. They are widely available in various configurations, including unions, tees, swivels, and bends, making them suitable for diverse applications. The O-ring provides an exceptionally tight seal that can withstand high pressures, which is particularly useful for hydraulic and other automotive applications. Additionally, these fittings allow for some flexibility, enabling them to be reassembled multiple times without the risk of cracks or deformation due to over tightening.
Disadvantages of ORB Fittings
Ironically, the O-ring, which is the key to ORB fittings’ effectiveness, can also be a point of vulnerability. To function under high pressures, the O-ring must also endure high temperatures. While the fittings themselves are made from high-grade steel capable of withstanding these conditions, the O-ring may melt or crack, leading to leaks. Furthermore, the O-ring must be compatible with the media it carries; otherwise, it may erode and cause a connection failure.
According to the sizing table, multiple thread standards can share the same pitch. Therefore, selecting an undersized fitting can result in a loose connection. Similarly, choosing a longer fitting than specified can lead to an improperly compressed O-ring.
QC Hydraulics has specialized in ORB (O-Ring Boss) hydraulic fittings for over 20 years. Our extensive experience and dedication to quality ensure that we provide the best products to meet your needs. If you have any requirements or specific demands for ORFS fittings, please do not hesitate to contact me. Our team is ready to assist you with expert advice and top-notch customer service to ensure you get the perfect solutions for your hydraulic systems.