If You Are A Piping Engineer
A welder who has not carried out welding work for more than six months must be re-qualified, because after a rest of six months, most welders do not have steady hands anymore. Their welds will not pass the x-ray tests.
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. There are cheats who don’t stick to this standard. But if they are caught the penalty will be very expensive.
Cathodic Protection uses anode like aluminum, magnesium or zinc. These three metals will corrode, thus saving the steel pipes. This is the method piping engineers used to solve their corrosion problems.
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. Contractors who want to cut corners must know that their corrupt means may cause the lives of other people in future. Moreover they may be legally held responsible if lives are lost or properties are damaged in future.
For pipes with diameter up to 300 mm, if the dent exceeds 6 mm, cut off the damaged portion as a cylinder. This is the piping standard and it is impossible to get away with it if the matter is exposed. One manager may help you to cover up the matter at the moment. What would happen if the next manager takes over?
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. Again this is the standard so that no one can nail you down in future.
All pipelines must be hydrostatically tested for a minimum period of 24 hours. Contractors who cheated on this had to carry out the reworks. Many cases happened in the past. The reputation of the contractor had gone into the drain.
All tie-in-welds must be 100 % radio graphically inspected. The latest plant explosion happened in China this month, and at least 119 people died. Some others are still missing. If the tie-in-welds were properly radio graphically inspected, the ammonia pipeline would not have leaked.
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. If you don’t follow these instructions, your welds will not pass the radio graphical tests. Won’t it be expensive to carry out the rework?
That joint next to the red clamp has been done by a semi-skilled welder.
If you need further reference, please log on to: http://www.spedweb.com/
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. There are cheats who don’t stick to this standard. But if they are caught the penalty will be very expensive.
Cathodic Protection uses anode like aluminum, magnesium or zinc. These three metals will corrode, thus saving the steel pipes. This is the method piping engineers used to solve their corrosion problems.
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. Contractors who want to cut corners must know that their corrupt means may cause the lives of other people in future. Moreover they may be legally held responsible if lives are lost or properties are damaged in future.
For pipes with diameter up to 300 mm, if the dent exceeds 6 mm, cut off the damaged portion as a cylinder. This is the piping standard and it is impossible to get away with it if the matter is exposed. One manager may help you to cover up the matter at the moment. What would happen if the next manager takes over?
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. Again this is the standard so that no one can nail you down in future.
All pipelines must be hydrostatically tested for a minimum period of 24 hours. Contractors who cheated on this had to carry out the reworks. Many cases happened in the past. The reputation of the contractor had gone into the drain.
All tie-in-welds must be 100 % radio graphically inspected. The latest plant explosion happened in China this month, and at least 119 people died. Some others are still missing. If the tie-in-welds were properly radio graphically inspected, the ammonia pipeline would not have leaked.
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. If you don’t follow these instructions, your welds will not pass the radio graphical tests. Won’t it be expensive to carry out the rework?
That joint next to the red clamp has been done by a semi-skilled welder.
If you need further reference, please log on to: http://www.spedweb.com/
No comments:
Post a Comment