Can the H44 swing type replace the H42 vertical check valve? If you know, please answer it. It's urgent.
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I would like to ask everyone, this is the case when the customer originally used the 41 lift check valve. After installation, it was found that there was a backflow phenomenon. After the drawings were sent, I found out that their installation direction was horizontal. If the 41 is installed horizontally, of course there will be leakage. The current situation is that the total length of 41 and 42 is different, with a difference of more than 50, and they cannot be installed even after sending them. Do you have any good ideas? The engineer suggested using H44 swing check valve. I wonder if it will work? Thank you everyone
Swing check valves should be available, which can be installed in vertical and horizontal pipelines.
Thank you. The customer's medium pressure is 0.2mpa. Usually our test pressure is above 0.5mpa. Does it need special treatment? Is there any backflow that will occur according to the normal pressure test? Because the place has already been put into production, it is urgent and must be confirmed, otherwise it will be very troublesome.
Generally there is no problem and there will be no backflow under normal circumstances.………………
It is normal for hard-sealed check valves to have backflow. As long as it's within reason. The manufacturing process of the current valve itself is poor, and the purge after the pipeline installation is completed is still an unstable factor.
The sealing of the check valve mainly relies on the pressure difference between the front and rear of the valve disc to seal. The larger the pressure difference, the better the sealing effect. No matter what kind of valve, there is a leakage rate. As long as there is a slight leakage, the pressure difference will definitely decrease over time, and the sealing effect will also decrease until the pressure before and after the valve disc is balanced. As mentioned above, purging and pressing when driving is very important. If there is foreign matter sticking to the sealing surface, it will easily cause poor sealing effect. This is very, very important. Therefore, the check valve cannot be used as a cut-off and isolation function. The longer it is left, the more serious the leakage will be.
Agree with 7th floor, the check valve cannot be used as a shut-off valve, backflow is normal
Swing check valves can be used, which can be installed in vertical and horizontal pipelines.
I don’t understand why the H41 lift check valve cannot be installed in horizontal pipelines? From the internal structure, H41 has a spring-assisted closing. Theoretically, in some cases, it should be better than the swing check valve. For example, if the pipeline pressure is insufficient, the check valve will have a backflow phenomenon, which is normal within the allowed standard range. Is there any other reason?
H41 is originally installed horizontally and is not recommended for vertical installation. Moreover, the sealing performance of H41 when installed horizontally is better than that of H44.