Khoom siv:
Siv rau hauv kev lag luam thiab pej xeem cov dej txias, dej kub, cua sov, cov kav dej kub, hluav taws kub-siv hnub ci piping thiab central deployment piping, thiab lwm yam.
Kev ua raws li tus qauv:
| GB/T 19228 YB/T 4204 |
| GB/T 12771 QB/T 2467 |
| JIS G3448 |
| TS EN 10312-3S |
