Pipe Joint

Pipe Joint


the connection at the ends of pipes that ensures tight sealing and strength. In some cases, pipe joints must also provide for rapid assembly and disassembly or a change in the direction of the line of pipe. The most common types used for general-purpose metal pipes are welded, flanged, threaded, and bell-and-spigot joints.

Welded joints are made between straight sections of pipe of the same diameter by butt-welding the pipe ends. Fittings are welded on where there are bends, branches, or changes in diameter in the line. Flanged joints are used where a line must be disassembled and assembled frequently. They consist of two flanges on the ends of the pipes being connected, a gasket, and fastening studs or bolts with nuts. Welded and flanged joints are used for pipe diameters up to 2,000 mm and internal pressures up to 1,000 meganewtons per m2 (MN/m2).

Threaded joints are made with pipes whose ends are threaded on the outside and fittings that have internal threads. With cylindrical threading, a seal is made by winding packing (usually hemp smeared with red lead) around the joint to fill the gaps between the threads on the pipe and the threads on the fitting. With conical threads, a seal is achieved without the packing. Threaded joints are used mainly for pipes having diameters up to 50 mm; with cylindrical threading, such joints are used for pressures up to 2.5 MN/m2, and with conical threading, for pressures up to 25 MN/m2.

Bell-and-spigot joints are used for pig-iron, ceramic, and concrete pipes that have short flares on one end. The gap between the spigot and bell ends of the connected pipes is sealed with packing material, such as lead, rubber, or cement. The advantages of bell-and-spigot joints include low manufacturing costs and the possibility of shifting the pipes axially. Such joints are used with pipes 50–500 mm in diameter for pressures up to 1 MN/m2.

Tubing with diameters less than 10 mm. used in the oil and gasoline lines of motor vehicles, tractors, and other machines at pressures up to 2 MN/m2, uses special fittings for connections. The tubing ends may be flared, or spherical or conical unions may be used.

Conical flanged glass pipe is joined by means of flange fittings and clamping bolts. The flange fittings, together with rubber inserts that mate with the surfaces of the pipe flanges, are put on the ends of the pipes, and a rubber or fluorocarbon-plastic gasket is laid in the butt joint between the pipes. Springs are often placed between the nuts of the clamping bolts and the flange fitting in order to reduce the possibility of breaking the pipe.

Quick-release pipe connections feature a collar with special clamps that allow the joint to be separated by the unscrewing of only one bolt. Hinged joints permit one pipe to be turned at angles up to 30° relative to the axis of the other pipe. These joints are usually used for pipe diameters of 25–500 mm and pressures up to 1 MN/m2.


References in periodicals archive ?
Tenders Are Invited for Joints Seal P Trap, Pipe Joint, Tee Joint, Door Bend in Ceiling of Kitchen in Basement of Trauma Centre at Aiims in Connection With a/r and M/o to Jpnatc Document cost : INR 885 EMD value : INR 2569 Opening date : 14 Mar 2018 Period of contract : 01 month
But referring to the gas pipe joint, he said: "It's in a tight space, you've got a boiler in front of you, a jig plate in front of you, and that's why testing methods are in place as well.
American Polywater's (APW) GrandSlam Pipe Joint Lubricant solves the common problems associated with other pipe joint lubricants.
The flexible coupling permits a limited amount of linear and angular movement at the pipe joint to accommodate expansion, contraction and deflection.
Digi-Tally's advanced class II eye safe laser pipe tally system measures and records the length of each pipe joint, then automatically creates a complete report file that can be printed, viewed, and saved for future reference, with the goal of providing more accurate, reliable, and cost effective field measurement methods.
Regrettably, accidents do happen and pipe joint failures have been responsible for a number of high profile industrial incidents around the world.
Produced and edited by the American Water Works Association, this reference volume provides a complete survey of best practices regarding applicable standards, manufacturing and testing, design, pipe joint and fitting specifications, thrust restraint design, interior linings and hydraulics, external corrosion protection, installation and purchasing guidelines.
Connections that rely on threaded pipes and fittings are prone to leaks if they're not sealed with either Teflon tape or Teflon pipe joint compound.
Pipe joint compound is applied to pipe threads before assembly.
One other thing, nearly all manufacturers of stoves tell you to secure each pipe joint with three screws or bolts for safety reasons.
Health officials said the rupture probably occurred either because valve malfunctioning pressurized the pipe beyond normal levels or because a pipe joint was damaged due to repeated pump motor vibrations.
1, inadequate sewer pipe joint performance can allow tree root intrusion, which can cause pipe blockage, ground water infiltration and sewage exfiltration.