How about the development and application of API standard safety valve? - 5

Release time:

2024-04-16

Through the test, these models have enough accuracy and reliability, and can be used in engineering research.

Through the study of the internal flow field of the safety valve, we have a new understanding of the internal flow of the safety valve. In the whole flow passage of safety valve, the throat of valve seat is the smallest geometric flow section. Therefore, in the process of engineering calculation and design of safety valve, the flow passage area is assumed to be the actual minimum aerodynamic flow area in the whole flow passage. If the flow field is in critical or supercritical flow state, the sound velocity will be reached at the throat of valve seat.

In the past, it has been proved that the critical section of safety valve is not at the throat of valve seat, but downstream. But what kind of flow field shape is it, and what is the mechanism of this phenomenon? These difficult questions can be easily solved by flow field simulation.

The flow of medium in the valve seat throat is subsonic. The actual aerodynamic critical section is located on the side of the cylinder formed between the valve seat and the valve disc.

In conclusion, API standard safety valve has remarkable characteristics and advancement compared with JB safety valve. In recent years, API standard safety valve has been widely used in China. Based on the analysis of current situation, the following suggestions are put forward:

1) Safety valve manufacturers, inspection units and user departments shall fully and completely understand, be familiar with and master API standards

(ASME Code) relevant contents and requirements.

2) The design unit and manufacturer shall strictly follow the requirements of API standard (ASME Code) to design, select materials and manufacture safety valves.

3) Each manufacturer shall carry out sufficient performance research on the API standard safety valve to show the characteristics of the API standard safety valve. Each manufacturer shall determine the discharge coefficient of the safety valve through the qualified testing department for the use of user selection.

4) At present, the production means and test conditions of domestic safety valve manufacturers are far behind those of foreign manufacturers, especially in terms of test conditions. Therefore, it is suggested that the manufacturer and inspection unit of safety valve should create conditions to meet the requirements of safety valve performance test. For example, the test device and container shall be of sufficient size and capacity. This involves the accuracy of reseating pressure and the judgment of mechanical properties.

5) The user of safety valve shall put forward clear ordering requirements for safety valve to the supplier (manufacturer), ask for relevant documents (such as certificate of conformity, quality certificate, test report, etc.) and conduct acceptance of necessary items when receiving the goods.