Spiral Weld Pipe : Pipe having a helical seam produced by automatic submerged-arc welding. At least one pass shall be made on the inside and at least one pass on the outside. (Spec 5L)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}