API 570 Quiz (ASME 31.3 – Quality Factor of Weld-joint and Casting)

In this very first and priority topic, we will try one by one of the Open/Close questions on Module ASME 31.3 – Quality Factor as a part of in-the-exam API 570 Body of knowledge (BOK) If you don’t know how API 510 Certification scheme, … Continue reading API 570 Quiz (ASME 31.3 – Quality Factor of Weld-joint and Casting)

Guide for selecting Gasket type

The Factors to consider when selecting a gasket Operating temperature and pressure, pipe size, temperature cycle, cost, chemical composition of fluid, fire resistance, radiation, etc In general of application, please use Pressure – Temperature chart as below for understanding the capability of each type of gasket. Sheet Gasket (Rubber gasket, Non-asbestos gasket, PTFE gasket, flexible graphite gasket) Rubber gasket is common with black color, but it is different. Compressed Synthetic Fiber Gasket (e.g. non asbestos or asbestos free) PTFE (Poly Tetra Flour Ethylene) Gasket Type: Virgin(Pure), Filled (Compressed Synthetic), Micro-cellular (Closed or Expanded), with thin metal reinforcement. Flexible Graphite Gasket … Continue reading Guide for selecting Gasket type

HDPE Piping (Theory, Features, Heat Fusion, etc.)

1. What is HDPE? High Density Polyethylene Synthetic resin prepared by polymerizing ethylene One of the general-purpose plastics used a lot in everyday life 2. Features and Application 1) Features: excellent weather resistance, environmental stress cracking resistance, water pressure resistance and workability. 2) Use: General sewer pipe (firefighters in domestic apartments, etc.-screw-in, plant UG-Heat Fusion) ※ Weather resistance: Withstands various climates. Difficulty rusting. ※  Environmental Stress Cracking Resistance 3. Heat Fusion Construction: Fusion Weld Machine = HDPE Welding Machine-Electrofusion Machine, etc.  Each company has a different name but the principle is similar. If the machine is installed according to the procedure, it will … Continue reading HDPE Piping (Theory, Features, Heat Fusion, etc.)

What is heterogeneous welding

Welded joint in which the weld metal and parent material have significant differences in mechanical properties and/or chemical composition. Example: A repair weld of a cast iron item performed with a nickel-based electrode. Heterogeneous welding is one way of performing fusion welding with the application of external filler whose metallurgical composition is substantially different from that of the base metals. So if filler material is applied during joining and the metallurgical composition of filler is different from that of the base metal then it is termed as heterogeneous welding. It is to be noted that heterogeneous welding is not a … Continue reading What is heterogeneous welding

What is Autogenous Welding

Autogenous welding is one way of performing fusion welding without the application of external filler material. It is to be noted that autogenous welding is not a particular type of welding process like MMAW, TIG, GMAW, etc.; instead, it is one of the three different ways or modes of doing fusion welding. Note that solid state welding processes are usually autogenous as they don’t use any filler during welding. Tungsten Inter Gas (TIG) and oxy-fuel welding processes can be performed in autogenous mode/way. Various advanced welding processes, such as Plasma Arc Welding (PAW), Laser Beam Welding (LBW), Electron Beam Welding … Continue reading What is Autogenous Welding

Typical welding deposition rate

When welding using a fusion process, the edges of a component are melted together to form weld metal. Table: Heat source, mode of shielding, thickness range and metal deposition rates for various fusion processes Process Heat source Shield Parent metal thickness mm Deposition rate kg/hr Arc MMA Arc Gas/flux 1-100 1-4 MIG Arc Gas 0.5-100 1-8 TIG Arc Gas 0.1-100 1-4 SAW Arc Flux 5-250 5-20 ES/EG Resistance/arc Flux/gas 5-250 5-20 Stud Arc – 4-20 – Gas Oxyfuel Flame Gas 0.6-10 1-2 Power beam Laser Radiation Gas 0.2-25 – EB Electrons Vacuum 0.2-250 – Resistance Spot/Seam Resistance – 0.2-10 – Thermit Thermit Chemical … Continue reading Typical welding deposition rate

How to choose a suitable welding process

Factors which must be taken into account when choosing a suitable welding or joining process are: material type product form: plate or tubular quality and strength requirements degree of mechanization capital cost Although consideration of these factors will identify the most suitable welding process, the choice within a company may be restricted by the cost of implementing a new process, availability of plant or current workforce skill. Welding and joining processes available to the welding engineer can be separated into the following generic types: Fusion arc gas power beam resistance Thermomechanical friction flash explosive Mechanical fasteners Solid state adhesive soldering … Continue reading How to choose a suitable welding process