H42Y、H42W升降立式止回閥正常處于關(guān)閉狀態(tài)，由于管線中進口端介質(zhì)的壓力作用，而克服彈簧阻力使閥門開啟。當進口端介質(zhì)壓力低于出口端時，彈簧將閥芯推向閥座而使閥門關(guān)閉，阻止介質(zhì)逆流，故起止回作用
主要外形尺寸
| 公稱壓力 PN | DN | D0 | D | DI | Md | Z-D | H | b | 重量 (㎏) |
| 16.0MPa | 15 | 15 | 95 | 60 | M24×2 | 3-18 | 240 | 20 | 5.5 |
| 25 | 23 | 105 | 68 | M33×2 | 3-18 | 262 | 20 | 7.5 | |
| 32 | 29 | 115 | 80 | M42×2 | 4-18 | 285 | 22 | 10 | |
| 40 | 39 | 165 | 115 | M52×2 | 6-26 | 285 | 28 | 19.5 | |
| 32.0MPa | 10 | 11 | 95 | 60 | M24×2 | 3-18 | 234 | 20 | 5.5 |
| 15 | 17 | 105 | 68 | M33×2 | 3-18 | 240 | 20 | 6 | |
| 25 | 23 | 115 | 80 | M42×2 | 4-18 | 262 | 22 | 8.5 | |
| 32 | 29 | 135 | 95 | M48×2 | 4-22 | 285 | 25 | 12 | |
| 40 | 42 | 165 | 115 | M64×2 | 6-26 | 316 | 32 | 21 |
