Hard PVC pipe has a nominal outside diameter 50CM, but soft PVC pipe is generally the largest of 50mm. pvc pipe fittings rigid PVC pipe specifications: GB / T13020-1991 soft PVC pipe specifications: GB / T13527.1-1992 rigid PVC pipe has a nominal diameter units have :( mm) 2.5,3,4,5,6, .. ... 355,400,450,500,560,630,710,800,900,1000 such as PVC-U and PVC-U difference UPVC and UPVC is what we usually say that the PVC pipe, but the wording of the order just not the same . PVC production process, in order to increase the performance of PVC plastics, improve productivity, added plasticizer (such as DOP, DBP, DINP, etc.), and add the plasticizer in PVC products will be relatively soft. Generally, we will not add processing plasticizer in PVC products collectively known as UPVC pvc pipe, also writing PVC-U. Industrial PVC resin is mainly amorphous structure, but it also contains some crystalline regions (approximately 5%) environmental pvc pipe, so there is no clear PVC melting point of about 80 ℃ begins to soften professional pvc pipe, heat distortion temperature (1.82MPa under a load) of 70-71 ℃, under pressure at 150 ℃ begins to flow, and slowly release hydrogen chloride, resulting in discoloration of PVC (from yellow to red, brown, and even black). Industrial PVC weight average molecular weight in the range of 4.8-4.8 million and a corresponding number average molecular weight of 2-1.95 million. The vast majority of industrial resin weight average molecular mass of 10-20 million and the number average molecular weight in the 4.55-6.4 million. Rigid PVC (unplasticized) has good mechanical strength, weather resistance and flame resistance, can be used alone as structural materials used in chemical manufacturing pipes, sheet metal and plastic injection products. Rigid PVC can be used to enhance the material. pvc material processing a pigment in certain metal ions will lead to PVC resin thermal oxidative decomposition. Determination method pigmented polyethylene was heated to 180 ℃ when the change of hue. Since the pigment contained in the metal ions to promote accelerated decomposition of PVC, resulting in change of hue. Meanwhile, note that the same added lake red PVC can produce different color, such as those containing calcium, the color difference is small; manganese is large color difference, which is due to the manganese metal promoter PVC dehydrochlorination due. Sulfide-based colorant (such as cadmium red, yellow, etc.) used in PVC coloring, coloring agents may be due to the decomposition of hydrogen sulfide release. Such colorants should not be mixed with lead stabilizers in order to avoid generating the black lead sulfide. 2. Influence of Pigments on PVC insulation of electrical cable materials as PVC and polyethylene as the electrical properties should be considered after coloring. Especially for its own PVC insulation resistance than polyethylene is poor, so the impact is even greater pigment. Instructions, select its inorganic pigments coloring PVC electrical insulation is better than the organic pigments professional pvc pipe, sea Widex (certified), pvc pipe provided by Widex Qingdao Rubber Material Co., Widex Qingdao Rubber Material Co., Ltd. (www.haihuidaxiangsu.com) is Qingdao, industrial products leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Widex leadership in the sea with the staff warmly welcome all inquiries negotiations to create sea Widex a better future.