Video Aula - transitioned from Raiz SA 335 P22 Soldiers tiger ( Root Pass Welding SA 335 P22 tiger ). Notice

In accordance with ANSI B 16.05 For pipes with wall thickness "t" a maximum of 7/8 " or 22.2 mm, the bevel should be 37.5 ° ± 2.5 º and land of 1/16 "± 1/32" or 1.6 mm ± .8 mm For pipes with wall thickness "t" greater than 7/8 "or 22.2 mm We keep the measures of land But, to the measure of 3/4 "or 19 mm We do a bevel 37.5 º ± 2.5 º and the rest of the thickness "t" We make a bevel of only 10 ± 1 º This will give a smaller weld volume, and with less residual stress in the weld. Fittings and pipes are protected with paints and mill scale to avoid rust we remove these paint and mill scale making the joint completely clean. Watch now how the bevel is very clean. We do not use thermal cutting (torch) to cut this kind of material because it will form martensite in the area cut and will leave the joint weak. Also on the bevels, not used cutting torch we used here a bevel pipe machien that will do the cut to cold. We checked the angle of the bevel with the help of a protractor Ten, twenty, thirty-seven point five We do a test with liquid penetrating on bevels. This is to check for defect in the base metal before of welding After dry the washing we apply the developer. next we apply a varnish antioxidant, for the bevels not rust. To the alignment bars that will be used in the fit-up We cut they of same material of pipe, in other words A335 P22 We use a welding gage named Hi-LO To align the pipes on the inside Note here that there is a misalignment of 2.5 mm In this case the fit-up are rejected The pipes must be fit-up again. During the fit-up also we used the TIG process. In the place where will be put the alignment bars Also We make a preheating to not weaken the base material. the filler metal for this base material will be a rod of 1/8" and especification AWS ER90S-B3 This is a standard torch with valve, model HW 26. We will use this torch which was specially devepelod for welding on construction site. See here that the valve that releases and closes the flow of shielding gas it has a different format Thus, do not has nothing disturbing the hand of welde in the hand torch See how works this kind of valve. Just turn 1/4 turn that the gas is released or closed. another feature this torch is that your head is in especial stainless steel thus ensuring useful lifetime increased on construction site. Here I will also use this collet, which has no slots and has a electric contact in the tungsten electrode much better that this other with slot. We make a preheating with temperature of 200ºC (392ºF) to 250ºC (482ºF) and we keep the interpass temperature between 250ºC (482ºF) to 300ºC (572ºF) Here is the start of the weld in position 6 clock hours. See how it is fed the filler rod by the inside of the pipe. The filler rod lightly touches the weld de pool. it should not enter into the groove and also do not let filler metal on the weld pool. This oxides that appear here, is because this material has chrome, and we are not using any gas purge on the position between 9 to 10 o'clock The filler rod enter inside of groove chanfro But, only the thickness of land. See now the filler rod are lightly above of weld pool. Once again I repeat these oxides that appear here are because of chrome existing in this kind of material and because we are not using any purge gas. See how this torch is lightweight and eases a lot motion of the hands of the welder Note that the power cable is not wrapped on the arm of the welder, Some welding inspectors do not allow the welder do it. See now through the lens. On the position between 11 to 12 o'clock we keep the filler rod in the middle of land (root face) to not have excess of penetration inside the pipe. Here we have the root pass finished Now we start the hot pass See the welder changes the position of torch without interrupting the electric arc Feed the weld pool all the time and do not let lack filler metal on the weld pool. See now on top of the pipe, in the position between 11 to 12 o'clock. Here we have hot pass finished If the filling pass with SMAW process revestido not start immediately after the hot pass with TIG We cover the joint with a welding blanket to the weld coll slowly