American Society for Testing and Materials (ASTM). Current edition approved Oct. 1, 2005. Published November 2005. Originally approved in 1964. Last previous edition approved in 2001 as A 523 – 96 (2001). 5 p. This specification covers seamless and electricresistance-welded steel pipe used as conduit for the installation of high-pressure pipe-type electrical cables in NPS 4 to NPS 12, inclusive, with nominal (average) wall thicknesses 0.219 to 0.562 in., depending on size. Pipe having other dimensions (Note 2) may be furnished, provided such pipe complies with all other requirements of this specification.