Galvanized single piece steel tube for boring well comprises a filter zone arranged in slotted bridge filter arrangement having slotted bridges, which extend itself in longitudinal direction of the steel tube

摘要

The galvanized single piece steel tube for boring well, has a filter zone (2) arranged in slotted bridge filter arrangement for drilling well. The filter arrangement consists slotted bridges embossed-out from the tube wall. The slotted bridges extend itself in longitudinal direction of the steel tube in which inner- and outer sides are galvanized, and are overlapped with one another. The slotted bridges are arranged against each other in circumference direction and are transferred group wise in ring zone on the circumference of the tube and group wise in axial direction of the steel tube. The galvanized single piece steel tube for boring well, has a filter zone (2) arranged in slotted bridge filter arrangement for drilling well. The filter arrangement consists slotted bridges embossed-out from the tube wall. The slotted bridges extend itself in longitudinal direction of the steel tube in which inner- and outer sides are galvanized, and are overlapped with one another. The slotted bridges are arranged against each other in circumference direction and are transferred group wise in ring zone on the circumference of the tube and group wise in axial direction of the steel tube. The free passage of the filter zone is 8-10% of the total area of the filter zone. The wall thickness-, slit width-, bridge width-, average slit length-, slotted bridge opening- and division of the steel tube are 4-6 mm, 4.5 mm, 5.3 mm, 17 mm, 0.5-1 mm and 37 mm respectively. The length of the steel tube is 6 m.