Basics for Piping Engineer
Basics for piping engineer
The following basics are what a piping engineer is expected to know:
1) A welder who has not carried out welding work for more than six months must be re-qualified.
2) When pipes are galvanized with zinc, the zinc coating must be at least 10 microns, to be effective. A human hair is about 50 microns in diameter.
3) Cathodic Protection uses anode like aluminum, magnesium or zinc. These three metals will corrode, thus saving the steel pipes.
4) Stainless steel 304L and 316L contain less than 0.03 % carbon. They are useful for welding rods because of the low carbon content which reduces the corrosion and brittleness at the edge of the welds.
5) For pipes with diameter up to 300 mm, if the dent exceeds 6 mm, cut off the damaged portion as a cylinder.
6) For pipes with over 300 mm diameter, if the dent is 2% of the diameter or more, cut off the damaged portion as a cylinder.
7) All pipelines must be hydrostatically tested for a minimum period of 24 hours.
8) All tie-in-welds must be 100 % radio graphically inspected.
9) The most common electrodes for piping is 1/8 inch diameter, E 7018. The recommended ampere is from 115 to 165. This rod is designed for all-position welding, with high linear speed. If these rods are exposed for more than four hours, they must be re-dried before use. The recommended oven temperature is from 700 to 800 degrees F. The drying time is from 1 to 2 hours. The best thing to do is to put all the unused rods in a heater while the welding job is in progress.
The following basics are what a piping engineer is expected to know:
1) A welder who has not carried out welding work for more than six months must be re-qualified.
2) When pipes are galvanized with zinc, the zinc coating must be at least 10 microns, to be effective. A human hair is about 50 microns in diameter.
3) Cathodic Protection uses anode like aluminum, magnesium or zinc. These three metals will corrode, thus saving the steel pipes.
4) Stainless steel 304L and 316L contain less than 0.03 % carbon. They are useful for welding rods because of the low carbon content which reduces the corrosion and brittleness at the edge of the welds.
5) For pipes with diameter up to 300 mm, if the dent exceeds 6 mm, cut off the damaged portion as a cylinder.
6) For pipes with over 300 mm diameter, if the dent is 2% of the diameter or more, cut off the damaged portion as a cylinder.
7) All pipelines must be hydrostatically tested for a minimum period of 24 hours.
8) All tie-in-welds must be 100 % radio graphically inspected.
9) The most common electrodes for piping is 1/8 inch diameter, E 7018. The recommended ampere is from 115 to 165. This rod is designed for all-position welding, with high linear speed. If these rods are exposed for more than four hours, they must be re-dried before use. The recommended oven temperature is from 700 to 800 degrees F. The drying time is from 1 to 2 hours. The best thing to do is to put all the unused rods in a heater while the welding job is in progress.
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