PART 8: TECHNIQUE VARIABLES Key Notes: The mean of Weaving will increase the heat input, hence the Toughness will be reduced accordingly. The change from multi-pass to single-pass will reduce the toughness significantly, the deduction of R.O.L and omission of bead tempering concepts will reduce the weld metal’s mechanical in general.   Continue reading Welding Inspector & WPS (PART 8 – FINAL)

PART 7: ELECTRICAL CHARACTERISTICS VARIABLES Key Notes: * In case of WPS with CVN impact test and no PWHT requirement: As common sense dictates, the Welding inspector will take a look on Weld bead profile firstly. The increase of Weld bead (Width) or reduction of R.O.L (Run out length) which makes toughness deduction. From the Welding engineer point of views, the limitation of welding weaving bead should to be mentioned wisely as below example for SMAW:   Continue reading Welding Inspector & WPS (PART 7)

PART 6: GAS VARIABLES Key Notes: * The mixture of %Nitrogen in DSS welding shielding gas. Normally, the shileding gas used for DSS welding is Pure Argon (100% Ar) with the right techniques. But the Ferrite content (FN)  will be a big trouble to the Welding quality, however, the small quantity of %Nitrogen (2-5%) will help to protect the FN from over the range of (40-70 FN). Above information for your reference only, further discussion about the DSS/SS-welding metallurgy will be carried out in separated topic. * The deletion of backing purge when welding SS. “TIG (GTAW) welding of the … Continue reading Welding Inspector & WPS (PART 6)

PART 5: PRE-HEATING AND HEAT TREATMENT VARIABLES Normally, there’s no issue on this variable because almost the PWHT Heating devices are working in order with the correct set-up temperature range and monitoring/record system. EXAMPLE OF AN PWHT PROCEDURE: Continue reading Welding Inspector & WPS (PART 5)

PART 4: POSITION VARIABLES Key Notes: * For the ASME PQR running without CVN impact test: Any PQR position can qualified for ALL position. (QW 203) * For the ASME PQR running with CVN impact test: It’s advised to run PQR 6G (or 3G, 5G) position for qualifying all the positions of piping welding onsite/workshop. Hence, there will be no any issue later on. * For the AWS D1.1 PQR, to qualified all position, at least Three (3) PQR 2G/3G/4G qo be carried out as per Tab 4.1 But there’re still flexibility gap if the project can optimize the Rule of … Continue reading Welding Inspector & WPS (PART 4)

PART 3: FILLER METAL VARIABLES Filler metal variable is very sensitive item in WPS those mainly affect to the weldment mechanical and properties. Ideally, all the variables have to be kept as the same with PQR. There’re still some flexible gap, however, the below experienced lesson learns may help to resolve the common problems with WPS those relating to the changes of Filler metal variables. Key Notes: * ASME IX QW 404.12 vs 404.33 – AWS specification changed. * AWS D1.1 THE ABILITY TO RESOLVE ABOVE PROBLEMS IS LESS POSSIBLE (WE CAN CHANGE THE BRAND NAME OR REDUCE FILLER STRENGTH … Continue reading Welding Inspector & WPS (PART 3)

PART 2 : BASE MATERIAL VARIABLES Key Notes: * WPS – CVN with min.thickness is 16mm (ASME IX & AWS D1.1) * AWS D1.1 ONLY: TAB 4.1 –> (28) Diameter range for pipe welding is > 600 mm (24 inch) * Example of ASME IX 11&5 QUESTION: How about the unlisted material like SS400 Flange welded to API 5L pipe * Example of AWS D1.1 29&1 SPECIAL NOTE: ASME IX only! Example of Thickness combination by various PQR to make new WPS (with the same variables of mother PQR, even the CVN).   Continue reading Welding Inspector & WPS (PART 2)

First glances of Welding Codes Application: Initial Concepts of Variables: B2.1 VARIABLES D1.1 VARIABLES ASME IX VARIABLES The Changes of Variables affecting to WPS qualification status: KEY NOTES: *  Groove changes mean : U —> V, J —> V, X —> V ect., (excluded the T-Y-K Jacket joints) *  CJP groove mean of using Backing/Backgouging  * Groove weld is different with Fillet weld (Weld type including Groove & Fillet) WPS with Groove type can cover the Fillet, but Fillet WPS can cover only Fillet weld ASME IX FILLET JOINT QUALIFICATION B2.1 FILLET JOINT QUALIFICATION D1.1 FILLET JOINT QUALIFICATION * ONLY … Continue reading Welding Inspector & WPS (PART 1)