The pipes are used for carrying sewage, water, oil or gas. Therefore, the weld seams produced during the manufacture of the pipe must be absolutely leaktight.
用于传输城市污水，水，油或者天然气的管道在焊接时必须保证严格的密封以防止泄露。
2
The standard covers dimensions and gaging of plastic tapered National Pipe Threads (NPT) for leak-tight joints, and it is now referenced in all ASTM Standards for plastic piping products.
V47 temperature actuated valve features light weight, small volume and long life. The valve body is made of high temperature seal components for avoiding valve body Hugging tight or leak.