Is it possible to install a wafer-type butterfly valve on a lined pipe together with a check valve?
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While installing the outlet piping for a process water pump, I encountered such a problem and would like to ask for everyone’s advice: There is a check valve followed by a wafer-type butterfly valve at the pump outlet. The piping required is plastic-lined pipe. I wonder if it’s possible to install the butterfly valve directly after the check valve? (That is, is it feasible to have no flanges between the two valves?) ) Because in some cases, when the butterfly valve or check valve is opened/closed, its valve disc may strike the inner wall of the lined pipe.
No, because when the butterfly valve is opened, the valve disc gets blocked and cannot be fully opened
For wafer-type butterfly valves, a pair of flanges is required for clamping; the length of the double-headed bolts should be sufficient to accommodate the two flanges, the butterfly valve itself, along with two gaskets, two nuts, and the screws, leaving a margin of 1–2 turns. Such valves cannot be installed directly behind check valves.
If it can be ensured that the valve disc is not obstructed when the butterfly valve is opened, allowing it to open fully, it can also be installed on a check valve. However, under normal circumstances, the check valve should be installed behind the valve to facilitate maintenance; if the butterfly valve is connected directly to the check valve, it makes maintenance difficult. It is inconvenient to operate for any future valve replacement or maintenance.
I strongly agree with the view from the 4th floor. However, the problem in this case is that the valve disc of the butterfly valve comes into contact with the lining. Hehe, this is a tricky issue; perhaps it would be better to grind it until there is no more contact. I remember doing the same thing when working on piping systems for different projects in the past
I’m not quite sure whether the butterfly valves and check valves mentioned on the 4th floor being connected directly makes it difficult to replace or maintain the valves. Could you be more specific? Thank you! This post was last edited by jerrypan on 2008-4-3 15:37.]
If the butterfly valve can be opened without touching the check valve, a wafer-type check valve can also be used; they can be installed and removed together. Hehe, but it’s rare to see the case where they don’t touch it.