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Learn about the various types of pipe fittings and connectors, including flared, threaded, welded, brazed, and flange connectors. Discover how these fittings create positive seals in fluid power systems and understand the different types of seals used.
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Pipe fitting • Threads on pipe fittings are tapered and rely on the stress generated by • forcing the tapered threads of the male half of the • fitting into the female half or component port. • Tightening the assembly's nut draws the fitting into the flared end of the tubing, resulting in a positive seal between the flared tube face and the fitting body. The flare fittings are designed for use with thin-wall to medium-thickness tubing in systems with operating pressures to 3,000 psi
It handles average fluid working pressures to 3,000 psi and is more tolerant of vibration than other types of all-metal fittings. • Tightening the fitting's nut onto the body draws a ferrule(ring) into the body. This compresses the ferrule around the tube, • causing the ferrule to contact, then penetrate the outer circumference of the tube, creating a positive seal.
Three basic types now are available: SAE straight-thread O-ring boss fittings, face seal or flat-face O-ring (FFOR) fittings, • and O-ring flange fittings. The choice between O-ring boss and FFOR fittings usually depends on such factors as fitting location, • wrench clearance, or individual preference. When a sleeve fits well, the arm is free to move, twist
A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. Threaded connectors: • These connectors are used in some low-pressure fluid power systems and are usually made of steel, copper, or brass, and are available in a variety of designs. • Threaded connectors are made with standard pipe threads cut on the inside surface. The end of the pipe is threaded with outside threads. Standard pipe threads are tapered slightly to ensure tight connections. Flange connectors: • Bolted flange connectors are suitable for most pressures now in use. The flanges are attached to the piping by welding, brazing, tapered threads (for some low-pressure systems), or rolling and bending into recesses.
Welded connectors: • The subassemblies of some fluid power systems are connected by welded joints, especially in high-pressure systems which use pipe for fluid lines. Brazed connectors: • Silver-brazed connectors are commonly used for joining nonferrous (copper, brass, and soon) piping in the pressure and temperature range where their use is practical. Use of this type of connector is limited to installations in which the piping temperature will not exceed 425°F and the pressure in cold lines will not-exceed 3,000 psi. Flared connectors: • Flared connectors are commonly used in fluid power systems containing lines made of tubing. These connectors provide safe, strong, dependable connections without the need for threading, welding, or soldering the tubing. The connector consists of a fitting, a sleeve, and a nut. • The fittings are made of steel, aluminum alloy, or bronze. This type of connector eliminates all tube flaring, yet provides a safe, strong, and depend- able tube connection. This connector consists of a fitting, a sleeve or ferrule, and a nut
Seal is relatively soft, non – metallic ring, captured in a groove or fixed in a combination of rings, forming a seal assembly, to block or separate fluid. • Fluid power seals are usually typed according to their shape or design. These types include T-seals, V-rings, O-rings, U-cups and so on. • The T-seal is always paired with two special extrusion-resisting backup rings, one on each side of the T. • The backup rings T-seals are used in applications where large clearances could occur as a result of the expansion of the • thin-walled hydraulic cylinder.
V-rings can provide excellent service life; otherwise, problems associated with friction, rod and seal wear, noise, and leakage can be expected. • The V-ring is the part of the packing set that does the sealing. It has a cross section resembling the letter V, from which its name is derived.