Hydraulic fittings are designed to connect tubing, pipe, and hose to various components used within the hydraulic system, such as valves, cylinders, or pumps. They provide a tightly sealed connection, prevent leakage, maintain a safe level of pressure, and direct the flow of hydraulic fluid.
Permanent fittings tend to be most common for hydraulic applications since they are permanent and the most reliable. Reusable fittings are connected with a wrench and a vise and are more expensive and time-consuming to assemble.
The 3 most common connection methods for hydraulic fittings are:
1. Interference Thread (Pipe Thread) Connectors: These were among the first type of threaded connectors developed and are widely used. They have a tapered thread by which a seal is made by deformation of the threads and require a thread tape or compound. Due to thread deformation, interference connections are generally used in permanent applications where the connection is not meant to be taken apart repeatedly. NPT (National Pipe Tapered) style pipe threads have been widely used for more than 100 years. NPT is a U.S. standard for tapered threads used on pipes and fittings.
2. Mechanical Seat Connectors: These were developed due to tapered thread limitations and are very common in most fluid power systems. Both male and female components have tapered seats. The seal is made by establishing contact between the male flared and female coned seat. Mechanical connections are still considered a permanent connection but are more friendly to applications with occasional disconnections. They do not require a sealing compound and may have issues in high-vibration environments. Common mechanical seat thread types are JIC 37° and SAE 45°.
3. O-Ring or Soft Seal Connectors: These are even newer and use a soft seal O-ring connecter to prevent leakage. They perform well in resisting vibration but can be affected by extreme temperatures and some types of fluids. They are among the best leakproof seals and are widely used in critical applications. Common O-Ring seal connections are Flat Face O-Ring, Flange Face Seal, and BOSS O-Ring.
At OmegaOne, we carry stainless steel hydraulic couplings and adapters, including barbed, crimp, compression, flare, threaded, and weld on.
Do you still have questions about the different connection methods for hydraulic fittings?
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