Joint TypeShapeAngle

Lap joint0 to 5

T-joint

5 to 90

Edge joint0 to 30

Corner jointGreater 30 less than 135

Butt joint

135 to 180

Cruciform joint90

Angle of bevel: the angle at which the edge of a component is prepared for making a weld.

V preparation for a MMA weld on carbon steel plates, this angle is 30.U preparation for a MMA weld on carbon steel plates, this angle is between 8-12. single bevel preparation for a MMA weld on carbon steel plates, this angle is 50. J preparation for a MMA weld on carbon steel plates, this angle is between 10-20.

Root face: the portion of a fusion face at the root that is not bevelled or grooved. 1-2 mm

Gap: minimum distance at any cross section between edges, ends or surfaces to be joined. 1-4 mm.

Root radius: the radius of the curved portion of the fusion face in a component prepared for a single J, single U, double J or double U weld.in case of single and double U preparations 6mmin case of single and double J preparations 8 mm

backing strip :- thickness of this backing strip is minimum 6 mm

Section 15X-rays used in the industrial radiography of welds generally have photon energies in the range 30keV up to 20MeV. Up to 400keV they are generated by conventional X-ray tubesAbove 400keV X-rays are produced using devices such as betatrons and linear accelerators.All sources of X-rays produce a continuous spectrum of radiation.Conventional X-ray units are capable of performing high quality radiography on steel of up to 60 mm thick.betatrons and linear accelerators are capable of penetrating in excess of 300 mm of steel.-raysThe early sources of -rays used in industrial radiography were in general composed of naturally occurring radiumThulium 90, Ytterbium 169, Iridium 192 and Cobalt 60In terms of steel Thulium 90 thickness of 7mm 90keV X-rays physical dimensions of less than 0.5 mm. Ytterbium 169 12mm 120keV X-rays physical dimensions of 2-3 mm Iridium 192 10-75 mm 500 keV X-rays 2-3 mmCobalt 60 40-150 mm 1.2 MeV X-raysDye penetration method:-bellow temperature of 5c penetrant become viscous and above 60c it dry out.The principal factors affecting the type and degree of distortion are: Parent material properties Amount of restraint Joint design Part fit-up Welding procedure joints made in a single pass using deep penetration have little angular distortiondepositing an 8mm-leg length will result in the deposition of 57% additional weld metal.In the case of the flanged plate, the load should act on the flange to prevent local damage to the web at the load pointsDistortion is corrected by spot heating on the convex sideTMCP = Thermo-Mechanical Controlled Processingnormalisedafter working the steel (rolling or forging) to size, it is heated to ~900C and then allowed to cool in air to ambient temperature.solution annealedafter hot or cold working to size, steel heated to ~1100Csolution heat treated and rapidly cooled by quenching into water to prevent any carbides or other phases from formingapplied to austenitic stainless steels such as 304 & 316 gradesPwht is To enable welded joints to be machined to accurate dimensional tolerancesSoak temperature 700C to ~760C. soak times are 1h per 25mm thicknessOxy fuel cutting.oxygen purity below 95% cutting becomes a melt-and-wash action that is usually unacceptable.fuel gases used are acetylene, natural gas (methane), propane, propylene and MAPP gas (methylacetylene propadiene mixture).oxy-fuel cuts are characterised by: large kerf (1mm)arc-air gouging => it is approximately 5 times faster than chippingin MMA welding stable weld pool must be maintained.Section 20Shock:- Primary voltage shock - 230 or 460 volts Secondary voltage shock - 60 to 100 voltsMost welding equipment is unlikely to exceed open circuit voltages of 100VDuty cycles are based on a total time of 10 minutesType of lightWavelength (nanometres)

Infrared (heat)>700

Visible light400-700

Ultraviolet radiation ~300C) H will diffuse quite rapidly and escape into the atmosphere rather than be trapped and cause embrittlement.To reduce cold cracking ,applying a suitable pre-heat temperature (typically 50 to ~250C)maintaining the pre-heat temperature (or raising it to ~250C) when welding has finished and holding the joint at this temperature for a number of hours (minimum 2 hours) to facilitatethe escape of H (called post-heat)iron sulphides that remain liquid when the bead has cooled down as low as ~980C, whereas bead solidification started at above 1400C.Adjustable fillet gauge

Measures fillet welds from 3-25 mm (1/8-1") with 0.8 mm (1/32") accuracy. It uses an offset arm, which slides, at a 45 angle to make fillet weld length measurements. This gauge also measures weld throat thickness to 1.5 mm (1/16").

Fillet weld gauge

Measures weld sizes from 3mm (1/8") up to 25mm (1")In general, thicker materials will require higher preheat temperatures, but for a given Ceq% and arc energy/heat input, preheat temperatures are likely to remain similar for wall thickness up to approximately 20mm.Preheat temperature is the temperature of the work piece in the weld zone immediately before any welding operation (including tack welding!) normally expressed as a minimum, but can also be specified as a range.

Interpass temperature is the temperature of the weld during welding and between passes in a multirun weld and adjacent parent metal immediately prior to the application of the next run normally expressed as a maximum, but should not drop below the minimum preheat temperature

Preheat maintenance temperature is the minimum temperature in the weld zone which shall be maintained if welding is interrupted shall be monitored during interruptionsection 24INSTRUMENTS FOR CALIBRATION be at least twice, and preferably five times, more accurate than the accuracy required for the Grade of equipment