GB/t229钢管金属低温冲击试验方法
2.1.1.1钢管应按现行国家标准《金属低温冲击试验方法》(GB/t229)的要求进行试验,其指标应不低于规定值的下限。
2.1.1.2燃气钢管的弯头、三通、异径管应采用机加工管件,其质量应符合现行和国家标准《钢制对焊无缝管件》GB12459的要求。
2.1.1.3管道焊接按现行国家标准《工业金属管道工程施工及验收规范》(GB 50235)和《现场设备及工业管道焊工施工及验收规范》(GB 50236)的有关规定进行。
2.1.1.4法兰安装前应进行外观检查,符合JB/T74《管道法兰及垫片技术条件》的要求
1) 法兰公称压力应符合设计要求。
2) 法兰密封面应光滑,无毛刺和径向沟槽。法兰螺纹应完整无损伤。凹凸法兰应能自然配合,凸面高度不应低于坡口深度。
2.1.1.5法兰垫片应符合JB/T74《管道法兰和垫片规范》的要求
1) 石棉橡胶垫片、橡胶垫片、软塑料垫片等非金属垫片应柔软,无老化、变质、分层现象,表面无破损、起皱等缺陷。
2) 金属垫片的加工尺寸、精度、光洁度、硬度符合要求,表面无裂纹、毛刺、沟槽、径向划痕、锈斑等缺陷。
3) 金属包层垫片和缠绕垫片应无径向划伤、松动、翘曲等缺陷。
2.1.1.6材料到达现场后,应按要求提供相应的材料证明文件。
National standard for steel pipe - metal low temperature impact test method (GB / t229)
2.1.1.1 the steel pipe shall be tested according to the requirements of the current national standard metal low temperature impact test method (GB / t229), and its index shall not be lower than the lower limit of the specified value.
2.1.1.2 machine made pipe fittings should be used for elbows, tees and reducers of gas steel pipes, and their quality should meet the requirements of current and national standard "steel butt welded seamless pipe fittings" GB12459.
2.1.1.3 pipeline welding shall be carried out in accordance with the relevant provisions of the current national standards code for construction and acceptance of industrial metal pipeline engineering (GB 50235) and code for construction and acceptance of field equipment and industrial pipeline welders (GB 50236).
2.1.1.4 the flange shall be visually inspected before installation, and shall meet the requirements of JB / T74 specification of pipeline flange and gasket
1) The nominal pressure of flange shall meet the design requirements.
2) Flange sealing surface shall be smooth and smooth without burr and radial groove. Flange thread shall be complete without damage. The concave and convex flange shall be able to fit naturally, and the height of convex surface shall not be lower than the depth of groove.
2.1.1.5 flange gasket shall meet the requirements of JB / T74 specification of pipeline flange and gasket
1) Non metallic gaskets such as asbestos rubber gasket, rubber gasket and soft plastic gasket shall be flexible without aging, deterioration or delamination, and the surface shall be free from defects such as breakage and wrinkles.
2) The machining dimension, accuracy, finish and hardness of the metal gasket shall meet the requirements, and the surface shall be free of cracks, burrs, grooves, radial scratches, rust spots and other defects.
3) The metal clad gasket and spiral wound gasket shall be free of radial scratch, looseness, warpage and other defects.
2.1.1.6 after the materials arrive at the site, corresponding material certification documents shall be provided as required.
钢管国家标准《金属低温冲击试验法》GB/T229
2.1.1.1钢管按现行国家标准《金属低温冲击试验法》GB/T229的要求进行试验,其指标不得低于规定值的下限。
2.1.1.2燃气钢管的弯头、三通、异径接头、宜采用机制管件,其质量应符合现和国家标准《钢制对焊无缝管件》GB12459的规定。
2.1.1.3管道焊接应按现行国家标准《工业金属管道工程施工及验收规范》GB50235和《现场设备、工业管道焊接工施工及验收规范》GB50236的有关规定执行。
2.1.1.4法兰在安装前应进行外观检查,并应符合《管路法兰与垫片》JB/T74规范要求:
1)法兰的公称压力应符合设计要求。
2)法兰密封面应平整光洁,不得有毛刺及径向沟槽。法兰螺纹部分应完整,无损伤。凹凸面法兰应能自然嵌合,凸面的高度不得低于凹槽的深度。
2.1.1.5法兰垫片应符合《管路法兰与垫片》JB/T74规范要求:
1)石棉橡胶垫、橡胶垫及软塑料等非金属垫片应质地柔韧,不得有老化变质或分层现象,表面不应有折损、皱纹等缺陷。
2)金属垫片的加工尺寸、精度、光洁度及硬度应符合要求,表面不得有裂纹、毛刺、凹槽、径向划痕及锈斑等缺陷。
3)包金属及缠绕式垫片不应有径向划痕、松散、翘曲等缺陷。
2.1.1.6材料到场后,应按要求提供相应材质证明文件。
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