When flanged valves are connected directly, should the vertical lines in the middle be drawn or not? How many should there be?
Thread Content
This post was last edited by cust008 on 2026-1-14 at 12:42. It’s a regular homepage image showing a valve with flange connections, with a straight line on each side, something like this. So, how should it be drawn when two such valves are connected directly? I drew three versions; let’s see which one everyone thinks should be chosen? Is it a customary drawing method, or is it specified by some standard?
Some say it should look like the diagram in the first line above, with a short horizontal line added in the middle; this is to indicate that even if the valves are next to each other, a short horizontal line is still needed to show that they are two separate valves rather than one. I have never been able to find out what the original standard requires.
There aren’t many people at Hai Chuan these days; there’s no one to watch it during the day, and only a few people watch it at night. Is everyone this busy with work? Please take the time to answer, even though it’s a very basic question.
Two valves – the third type is the most common. However, in most cases, there is also a drain valve between the two valves. Indeed, as you said, fewer people are posting and reading posts these days, but I keep reading them. If you need any help in the future, feel free to message me directly or add me on WeChat and send me the link
My unit doesn’t have any vertical lines on the left, middle, or right; the elements are directly attached to each other. A note can be added to provide some clarification
Secondly, the vertical line represents a flange connection; the 2 valves are connected directly
Thank you all for your replies. Are there any explicit standard regulations for this? I searched for a long time but couldn’t find it. Also, are these official design documents? The kind with the design institute’s seal. If it’s the manufacturing company itself that is doing it, then there’s nothing to say.
Actually, I understand it the same way: the vertical line represents the pipe flange, not the valve flange. I’m trying to find the relevant standards right now, but I can’t locate them. I’m asking how others handle this; to make it more convincing, I’m also inquiring about how design firms proceed.
Valves usually come with a flange, so it should be the second drawing method