DIN 4926-1995《钢制沉井水喷头–ND400~ND1200》
This document lays down the measurements, materials and requirements for steel wellheads. The wellheads serve as the upper end of drilled wells for raising of water.#,,#
This document lays down the measurements, materials and requirements for steel wellheads. The wellheads serve as the upper end of drilled wells for raising of water.#,,#