
Safety valve as the best device for extra-pressure protection, will automatically open and fully discharge to protect the equipment pressure form going on rise when an equipment pressure lowers to the setting valve.
Safety valve cover is enclosed is order to protect dust and foreign matters from getting in and protect toxic and combustible media form over-flow. While the opened cover of the open-type safety valve, which benefits to lower the temperature inside of the spring chamber is mainly used for the pipeline and container with steam medium and the safety valve with aheat-scatterer is suitable for the medium with a tempera-ture over 350℃
For the safety valve with a wrench, it can be opened manually with the wrench when the medium’s pressure is up to over 75% of that at which the valve opens.
Fully-opened safety valve’s height of opening ≥the diameter of the flow path with a large amount of discharge, the height of opening for a micro-open safety valve the diameter of the flow path.

| Design reference | API RP520 |
| Structural length | API 526 |
| Flanged ends | ASME B16.5a |
| Test &inspection | API527 |
Note: The dimension of connecting flange can be designed according to customers’ requirements.
| No. | accessory name | Sign of Materials | ||||||||
| C | C6 | S | SM | SL | Mc | M | H | |||
| 1 | Body | WCB | WC6 | CF8 | CF8M | CF3M | WCB | Monel | Hast.C | |
| 2 | Seat | 304/316 | 304/316 | 316 | 316L | 316L | Monel | Monel | Hast.C | |
| 3 | Adjust ring | CF8 | CF8 | CF8M | CF8M | CF3M | CF8M | Monel | Hast.C | |
| 4 | Valve Clack | 304 | 304 | 316 | 316L | 316L | 630 | Monel | Hast.C | |
| 5 | Valve Clack Holder | 420 | 420 | 630 | 630 | 316L | 316L | Monel | Hast.C | |
| 6 | Guide | 304 | 304 | 304 | 316 | 316L | 316 | Monel | Hast.C | |
| 7 | Spring Seat | WCB | WCB | 420 | 420 | 420 | 420 | 420 | 420 | |
| 8 | Spring | 50CrVA | ||||||||
| 9 | Stem | 420 | ||||||||
| 10 | Bonnet | WCB | WC6 | CF8 | CF8M | CF3M | WCB | Monel | Hast.C | |
| 11 | Bellows | 316L | Monel | Hast.C | ||||||
Note: Major parts of the valve series and materials of sealing surface differ according to casual working condition and customers' special requirements.