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 570 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 Chill Plate in Welding

In general, butt joint welding is divided into two-sided welding welded on both sides and the back gouging must be applied due to poor welding quality at the first welding layer of the first one-sided welding. (Call completed joint penetration, See What is CJP in welding) For one-side welding method, a backing material, which is a backing material that prevents melting of molten metal, is attached to the backside of the base material, and then the welding wire is lowered to form an arc between the base material to weld the base material. Welded Chill Plate (or Permanent backing strip, … Continue reading What is Chill Plate in Welding

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