`High-pressure refinery vessels with shielded arc welding`

Narrator: Now let's look at the petroleum industry that provides the fuel and lubricants to keep our cars and trucks, railroads and airplanes moving efficiently up and down and across our country. In 1930, with the introduction of shielded arc welding, the oil men turned to welded construction for refinery pressure vessels, by which in some cases they were able to maintain pressures up to 5,000 pounds per square inch, or more than 150 times the pressure in your automobile tires. Such high pressures combined with high temperatures are not possible with any other method of construction.