Valve jam fault

1. Open the bypass valve of the safety valve at the top of the high-flash vapor separation tank (to prevent the safety valve from activating), and control the flash pressure properly； 2. Open the direct discharge valve at the bottom of the high flash tank, and control the level of the high flash liquid (make sure that people in the vicinity are evacuated during discharge) ； 3. Close the cut-off valves before and after the liquid level control valve for converting high flash point to true flash point, and carry out online treatment on the liquid level control valve. Processing completed; normal operation resumed, OK.

What was said upstairs is quite risky; generally, valves have internal leaks. It’s dangerous to handle this online – the water supply can be disconnected and the load reduced appropriately, until the valve is repaired before the supply is reconnected. This post was last edited by Coal Miner on 2009-2-16 22:23]

According to the moderators as well, doing so could achieve the goal, but it’s too dangerous and should not be encouraged. In addition to the method mentioned by the moderator, we can also reduce the load on the gasification furnace, cut off the drainage from the gasification furnace and the carbon scrubber to the systems downstream, and handle that valve as soon as it is ready – I have done this before, and it should work fine.

Upstairs, I don’t agree with you. How long can it be feasible to cut off the drainage? What are the dangers of cutting water open? Please give me some advice.

There was sticking in the high flash angle valve connecting to the gasifier, which led to high flash pressure and water contamination, affecting the stable operation of the system. The following actions were taken: 1. When trying to switch or adjust the valve from the control room, the angle valve stuck, causing the liquid level in the gasifier to drop rapidly. The personnel in the control room quickly closed the angle valve or the flow control valve (which had severe internal leakage). At the same time, interlocks related to the gasifier’s liquid level were activated on the ESD system, with two of the liquid level sensors being bypassed to prevent the gasifier’s liquid level from dropping too fast and causing it to shut down. 2. Simultaneously inform the personnel on site to quickly close either the valve in front of or behind the flow control valve, or any one of the valves in front of the angle valve, in order to maintain the liquid level in the vaporizer; meanwhile, the personnel in the control room should keep the high flash pressure under control. 3. Before opening the angle valve, the personnel on site open the valve leading to the sedimentation tank, and use the pressure in the high-flash tank to perform a backwash. The washed black water is sent to the sedimentation tank to see if it can dislodge the ash and debris blocking the angle valve. At the same time, contact the instrumentation staff to go to the site to prepare for repairing the clogged angle valve. 4. If the above measures do not work to relieve the jamming of the angle valve, and when the liquid level in the vaporizer drops to 26%, the personnel in the control room shall manually shut down the system to prevent the gas from R1301 from escaping into the high-pressure flash tank, which could lead to overpressure accidents in the equipment. Precautions during processing: 1. Strictly maintain stable liquid level in the gasification furnace (control the flow rate of quench water). 2. The control room ensures stable pressure and liquid level in the high-pressure flash tank. Regarding the handling of blockages or stuck valves in angle valves with high flash point to true flash point, those upstairs have already explained it very clearly. It depends on whether it is a level control valve assembly or angle valves used in a one-on-one switching configuration to determine the appropriate approach. This post was last edited by xuqinger on 2009-2-18 16:41]

Personally, I think one should open the valve fully, strike around the valve body, and then try to close it to see if that works. If the branch line is blocked, one can strike the blocked area. This is just for reference; other methods have already been mentioned by those above. This post was last edited by Langtaosha on 2009-2-17 at 23:16.]

It is also possible to reduce the system load to the flow rate at startup, keep the control system pressure below 10 kilograms, and divert the black water to the startup pipeline for processing. While this approach prevents the gasification system from stopping operation, the subsequent systems will definitely have to be shut down. I believe this is the safest option; I do not agree with the suggestion from the second floor, as it is too dangerous. Last edited by xuqinger on 2009-2-20 07:57.]