CYLINDRICAL PROTECTIVE MEMBER AND POLYETHYLENE PIPE WITH CYLINDRICAL PROTECTIVE MEMBER FOR GAS

PROBLEM TO BE SOLVED: To provide a technology related to a cylindrical protective member for covering outside of a polyethylene pipe for gas, in particular the cylindrical protective member of which installation work is easily carried out by folding back a sheet at its center in a width direction and keeping its both ends in the width direction in double-folded state, arranging fixed parts and non-fixed parts alternatively at both ends to form a cylinder shape there.SOLUTION: A cylindrical protective member covers an outside part of a polyethylene pipe of prescribed length for gas that is buried in the ground. The cylindrical protective member 1 is manufactured by a process in which a sheet 2 having substantially the same length as that of polyethylene material for gas and having a width larger than an outer peripheral length of the polyethylene pipe for gas is folded back at its center 2c in width direction, keeps both ends 21 in its width direction under double-folded state, and fixed parts 22 and non-fixed parts 23 are alternatively arranged at both end parts 21 to form a cylindrical shape. The sheet 2 is a product in which at least two woven sheets of synthetic resin flat yarn are laminated, a length of the fixed parts 22 is 400 mm to 800 mm, a length of the non-fixed parts 23 is 70 mm to 200 mm and a tear strength of the fixed parts 22 is 20 N to 40 N.SELECTED DRAWING: Figure 1 【課題】ガス用ポリエチレン管の外側を覆う筒状保護部材に係り、特に、シートを幅方向中心で折返して、幅方向の両端部を二重にした状態で、両端部に固着部と非固着部とを交互に設けて筒状に形成して、ガス用ポリエチレン管の施工が容易な筒状保護部材とした技術である。【解決手段】地中に埋設される所定長のガス用ポリエチレン管の外側を覆う筒状保護部材であって、筒状保護部材１は、ガス用ポリエチレンと略同じ長さと、ガス用ポリエチレン管の外周長さよりも大きな幅とを有するシート２を幅方向中心２ｃで折返して、幅方向の両端部２１を二重にした状態で、両端部２１に固着部２２と非固着部２３とを交互に設けて筒状に形成し、シート２は、少なくとも合成樹脂製のフラットヤーンの織布２枚をラミネートしたものであり、固着部２２の長さを４００ｍｍ〜８００ｍｍとし、非固着部２３の長さを７０ｍｍ〜２００ｍｍとし、固着部２２の引裂強さを２０Ｎ〜４０Ｎとしたものである。【選択図】図１