Abnormal noise from the check valve at the outlet of the Roots blower
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The last edit to this post was made by Confide in the wind on 2022-6-21 at 22:04. The check valve at the outlet of the Roots blower makes a loud noise whenever the blower starts up. When the blower is started, it operates at 2 Hz; as the frequency increases gradually, there is no noise at first, but the noise gets louder as the frequency rises. What could be the reason for this?
Two identical fans: one does not make any noise under any operating conditions, regardless of whether there is pressure buildup behind it
This situation occurs most often when the pressure difference across the check valve is small and the flow rate is at its lowest. Horizontal installation is also one of the reasons. Additionally, the gas usage mode of the gas unit is the main cause of this phenomenon. For reference.
Thank you, but there are two fans, one in use and one as a backup, while the other one doesn’t have this feature. Thank you
When this situation occurs, it is necessary to see if the outlet pressure can be reduced by venting or other means in order to increase the flow rate; if the abnormal noises are eliminated, it indicates that there is a problem with the process. Otherwise, the check valve will need to be inspected or replaced. The sound frequency seems to be related to the air usage unit; it’s not clear whether the fan was operating properly at the time the sound was produced. It may also be related to the level of installation of the check valve… It appears that it is still connected to the processing aspects (i.e., the air usage unit). This is for reference only.
A check valve remains open within its normal operating pressure range; otherwise, it stays closed. If it’s just about fixing the problem, you can try replacing it with a brand new one. If data support is desired, the pressure values at the outlets of the two fans can be collected for comparison. It is divided into three stages: startup, acceleration, and maximum speed.
This situation usually only occurs during startup; the airflow isn’t able to keep the check valve open, and it generally doesn’t happen after startup is complete. You can check what the gas flow rate is when this sound occurs, to see if it’s too low when a machine starts up.
“For two identical fans, one of them does not make any noise under any operating conditions, regardless of whether there is pressure buildup behind it. When installing a check valve of this type, it is necessary to ensure that its valve stem is horizontal; check whether the valve stem in this valve is horizontal – it is better to install it vertically. Suspected sticking of the valve stem
First, measure the current flowing through the motor of the fan when it is in operation, and then it is recommended to contact the fan manufacturer for advice