|
Lines NPS 2" and larger are usually butt-welded. This is the most economical and leak proof way of joining large diameter piping. A disadvantage of this type of joint is that weld metal may intrude inside of the piping. This may affect flow in services of fibrous material that may build up and clog the piping. A backing ring can be inserted in between the joint to prevent this. Socket Welded or Screwed joints are most commonly on lines of NPS 1 ½" and smaller. Socket welding has an advantage over screwed connections. By being a welding connection the absence of leakage is assured. This is a big factor when dangerous fluids or gases are being carried through the line. Also the is no chance of weld material entering the bore of the pipe. The joint is made by fillet welding around the circumference of the pipe. One disadvantage of socket weld joints is the 1/16" recess in the joint holds or pockets liquid. For this reason care in selection of this joint must be made, especially in services which could corrode away the welded joint in the pocket. Bolted flange joints: Flanges are expensive. Flanges are used to bolt to flange nozzles on equipment and for process lines that require periodic inspection and/or cleaning. The flange joint is made by bolting together two flanges and have a gasket placed in between them to create a leak proof seal. |
| Back to Main Site Page | Comments? | Back to Pipe Categories Page |
