What is Mock-up test for In-service Welding

Following the concerns of welding defects for in-service maintenance hot works, the Mock-up test should be performed to increase the confidence level of works. See this: In-service and maintenance welding defects Mock-Up Testing ;  This comes at a Mock-up Testing for In-service welding or welding On-stream … For onstream welding, while there is fluid flowing inside the pipe or equipment The most important is the safety that is not going to burn through the weld and weld it must not happen Hydrogen cracking (HIC) according to the method used to prove that the simulated welding or the Mock-up test.  In conducting a mock-up test, the workpiece must look like or represent the actual work in the matter including:  (1) Type ( Material Spec.), and the thickness of … Continue reading What is Mock-up test for In-service Welding

In service and maintenance welding defect

In-Service Welding Concerns;  When welding, repairing or modifying pipelines or equipment that are currently being used (In-Service), the most worrying is the leak of the fluid inside. While or after doing On-line Welding. The two main reasons that cause the leak are: Burn Through: While welding at the melting area of ​​the welding, the strength will be reduced. We may not be able to withstand the Pressure at  Service value. Weld Cracking or Hydrogen Induced Cracking (HIC) from welding. The additional concern in welding is the cooling rate. Since the inside of the pipe or equipment has fluid flow, it may … Continue reading In service and maintenance welding defect

AWS D1.1 2020 Changed notes

Below is a summary of the material changes made to the 2020 edition of AWS D1.1. Format changes – moving to 11 clauses from 9. This change was made to improve clarity and it includes the addition of reference tables, formatting to mimic the normal progression of welding procedure qualification, as well as other updates to improve ease of use. Additional requirements are added when using shielding gases for use with prequalified welding procedures. Revision of the requirements for the qualification of WPSs using waveform technology (Heat input, auto-calculation, and record.) Revisions made to the qualification requirements for inspection personnel … Continue reading AWS D1.1 2020 Changed notes

Slip-on Flange ASME B31.3 limitation

Slip-on Flanges Limits per ASME B31.3;  In the ASME B31.3 Piping Code, restrictions on slip-on flanges are specified as follows:  Use welding Double-Welded for  Service that causes Severe erosion, Crevice corrosion, and Cyclic loading  Service that is combustible, toxic and harmful to people  Service at temperatures below -101 C 2. Do not Slip-on Flanges with Service with high pressure than ASME B16.5 Flange Class 2500. 3. Avoid  Slip-on Flanges with  Service that changes the temperature up – downtime (, Many the Large Temperature Contact of Cycle), especially with  Flanges are not covered  Insulation, which will cause a change in the temperature of the  Flange and.  Pipe quickly and may lead to thermal fatigue cracking … Continue reading Slip-on Flange ASME B31.3 limitation

Tension Test Acceptance Criteria for Welding Procedure Qualification

Tension Test Acceptance Criteria for Welding Procedure Qualification per ASME IX;  To qualify the welding procedure according to the ASME Section IX, the mechanical properties of the test coupon must be tested. Tension Test, which is the test of the strength of the weld by The principle of ASME is that Weld Metal must be stronger than or equal to the strength of Base Metal. Therefore, the result of the Tension Test will have Acceptance Criteria as follows. The workpiece is torn/break at Base Metal: Ultimate Tensile Strength (UTS) or Failure Stress of the workpiece must be greater than 95% … Continue reading Tension Test Acceptance Criteria for Welding Procedure Qualification

What is Lamellar tearing

Welding Defects – Lamellar Tearing;  Lamellar Tear is a crack that is a step in the base metal under the welding line. The cracks lie parallel to the work surface, especially with the Rolled Steel Plate. Lamellar Tear is caused by Tensile Stress in Through-Thickness direction. This comes from the shrinkage of the weld and the base metal itself has impurities or inclusions that are parallel to the work surface Thus causing a tear or crack Lamellar Tearing up. Continue reading What is Lamellar tearing