It can prevent the water from flowing backward.
| Part Name | Material |
| Body | Cast iron |
| Seat | Cast iron |
| Sealing | Brass |
| Disc | Cast iron |
| Size: | DN50-DN300 |
| Norminal pressure(MPA) | 1.6 |
| Suitbk temperature | ≤200°C |
| Seal test(water) | 1.8mpa |
| Shell test(water) | 2.4mpa |
| Seal test (gas) | 0.6mpa |
| Suitable medium: | steam,water,oil |
| Face to face | BS 5153 |
| Flange end | BS4504 PN10/16 |



