国产成人在线观看_青青草91视频_日韩一二在线_天天操91_国产精品内射后入合集_四库成人免费视频

Forged steel globe valve overall design, there are three kinds of flange valve bonnet is bolt type bonnet, through the concave and convex surface connection, stainless steel band and flexible graphite wound gaskets, ring joint may be adopted according to the demand, the second is welding type bonnet, after thread sealing welding, and the rigid welding according to the requirements can be directly used, the third is the sealing cover, since the seal bonnet joint with thread.Products are widely used in petroleum, chemical, pharmaceutical, electric power and other working conditions of the pipeline.