In the flat position with the pipe being rolled or rotated the push travel angle works best. Pipe Welding in the flat position requires that the Welder make some adjustments to the normal angles and length of the welds during welding. If a chill ring is used the root pass may be made using E-7018 since it is not necessary to penetrate through the pipe.
After tacking the chill ring on the inside of the pipe, the pins are removed. When the chill ring is used the root opening is determined by the pins on the chill ring.
The chill ring works like a backing bar in groove welding and becomes a part of the welded joint. The picture below shows the tacks in a flat position pipe.įor some applications a chill ring may be used instead of an open root. When testing the tack may be removed using a cutting wheel to get a consistent root weld around the joint. The tacks must be strong enough to hold alignment while welding the root pass and should penetrate enough to become a part of the root pass. If part of the root gap is too narrow you may not be able to penetrate through the pipe in those areas.Īt least 4 tack welds should be placed around the pipe at 12 o’clock 6 o’clock 3 o’clock and 9 o’clock. If part of the root gap is too wide the key hole will open up too much while welding and instead of penetration you may have burn through (more than 1/8 reinforcement) on the inside. The root gap around the pipe must be consistent. It is extremely important to set up and tack weld the pipe properly, if the pipe is not aligned on the inside it is difficult to obtain the proper penetration through the pipe.
The pipe is assembled for welding by placing one piece on top of the other with a 1/8 electrode without flux on it between the pipe. The pictures below show the pipe beveling machine and the edge preparation. The slag is removed and the edges are ground smooth for welding a 1/8 landing or flat is applied to the pipe. The pipe coupons for welding are cut using the pipe beveling machine. The pipe welding positions covered are the 1G flat and rolled position, the 2G horizontal position, the 5G vertical position and the 6G fixed position as shown below. Welding pipe to pipe requires a higher degree of skill and is the topic of this supplement. When welding pipe to pipe the joint is similar to a vee groove and is often open root. When welding pipe flanges and some joints configurations the weld applied may be a fillet weld. Welding pipe is like welding any other structural shape and welding can take place in any of the normal positions for welding.
0 kommentar(er)
