Any chemical, physical, radiological, or biological substance in a drinking water is definde as "contaminant" (Environmental Protection Agency). Drinking water always has some amount of contaminants, they does not necessarily indicate that…

One can connect parts together in many ways. The most usual are fastening by bolts or rivets, soldering and welding. Welding is a process that creates a continuous joint upon large materials surfaces. This is the main feature of welding, e…