The natural gas check valve is making clicking sounds
Thread Content
DN400, 55KPa, American standard check valve (swing type); it stops making noise at a flow rate of 4700 cubic feet per hour or higher; before that, the greater the flow rate, the louder the noise and the more the pipeline shakes. Additionally, the DN300 model doesn’t have this issue; I’m seeking help. There is a elbow after the DN400 check valve – will that have an impact?
Are both airflow fluctuations and the weight of the valve disc factors that have an impact?
I guess when the flow rate is below 4700, the gas thrust is not sufficient to counteract the weight of the check valve; moreover, your discharge pressure is too low. Under these combined conditions, it isn’t enough to open the check valve, which opens only when the pressure in front of it rises to a certain level, and that’s what causes the noise.
Agree with the opinion from the 3rd floor; if it makes noise frequently, it means the switch is being used often. Why is the switch being used so frequently? It’s a problem with pressure; sometimes the valve can be opened, and other times it can’t. Check if there is a pressure gauge or something in front of the valve; there you should be able to see the range of pressure fluctuations.
The flow meter before the valve shows a stable pressure of 50 KPa; it sounds whenever the flow rate is stable or increasing (below 4700). Behind the valve is the boiler; the flow rate at full load is 6,000 cubic meters per hour, and the pressure adjustment range is even narrower. Is the selection inappropriate?
I also have a similar check valve here; the selection itself is fine – it’s mainly due to the operating conditions, as the air flow is unstable. If the noise persists for a long time, the valve plate may come loose; in such cases, a shock-absorbing check valve can be used
The answer above makes a lot of sense; you can take it as a reference. I’ve also learned * from it
There’s a clicking sound; could it be static electricity causing sparks?
In rotary check valves, the valve disc keeps vibrating up and down at low flow rates; it is only when the flow rate is high enough that the valve disc can open fully and cease vibrating. When the flow rate drops to a certain level, the pressure exerted by the fluid on the valve plate is no longer sufficient to counteract the weight of the valve plate, causing it to close and pressure to build up in the pipeline. When the pressure becomes high enough, the valve plate opens again; this repeated process generates the aforementioned noise. Throughout the entire sound generation process, as the flow rate increases from low to high, the distance between the valve plate and the valve seat also increases, and the force with which the valve plate impacts the valve seat grows as well; therefore, the sound produced increases as the flow rate rises. So, as you said, when the pipeline flow is less than 4700, the higher the flow rate, the louder the sound; whereas when the flow rate is greater than 4700, the valve plate does not come into contact with the valve seat during vibration, and thus no sound is produced. This kind of noise indicates that it may damage the sealing performance of the valve, so you need to be careful. The solutions are to increase the pipeline flow rate and reduce the weight of the valve plate.
If it’s due to the reasons I mentioned, I think a horizontally installed shuttle-type check valve can solve this problem; if anyone has tried this, they can share their experience
I agree with the view from the 3rd floor; the check valves used for natural gas intake at our plant are installed vertically, and they make a clicking sound even when the device is using a low flow rate of natural gas