What kind of valve is this?
Thread Content
Friends who know instrumentation can help me see how this valve is controlled?
There is too little content in your picture. I only see a three-way solenoid valve.
Since it has a valve group and a solenoid valve, it can be inferred that it is a regulating valve with an interlocking cut-off function.
The drawing is too small and does not show much content. You did not show the interlocking dotted line part of the automatic control valve.
One branch, one bypass, and the valve is a pneumatic valve. The valve switch or opening is controlled through instrument feedback signals. After the branch pneumatic valve fails, close the inlet and outlet valves of the pneumatic valve, and then open the bypass valve to ensure uninterrupted delivery of media. At this time, the pneumatic valve can be repaired.
This is a pneumatic cut-off valve with a chain. By installing a solenoid valve on the air line of the cut-off valve, the interlocking solenoid valve operates in an emergency state, closing the air line of the pneumatic cut-off valve and expelling air. The cut-off valve returns to its original state of air open or air closed.
It is recommended to read the description on the P&ID home page first. Generally speaking, SDV is shutdown VALUE, which can be understood as an emergency shut-off valve. The setting and design of emergency shut-off valves have corresponding requirements in many specifications, such as GB 50160-2018 "Code for Fire Protection Design of Petrochemical Enterprises", SH 3136-2003 "Code for Safety Design of Spherical Storage Tanks for Liquefied Hydrocarbons", Notice of the General Administration of Work Safety No. 3 [2014] No. 68 on further strengthening the safety management of chemical tank areas, etc. (there are too many to list them all), but it is recommended to take a look at API 553 -2012 Refinery Valves and Accessories for Control and Safety Instrumented Systems. When selecting remote control EBV (SDV), bypass should not be set (refer to 9.4.1 in SH/T3104-2013). This is an error in the figure. In addition, for the interpretation of graphic symbols, please refer to HGT2050 5. IA represents the letter of instrument air, two-position three-way solenoid valve (represented by S/SOV, charged excitation flux, arrow indicates power-off exhaust, you can refer to HGT20581), two slashes represent instrument air pipeline, and said represents cylinder actuator.……