Hello all
I was removing the backflow preventer in preparation for winter. The unit is a series of components and union joints. Whenever I turned one piece to loosen, the other side would tighten. I was able to remove the device by tightening one of the union pipes a good amount, allowing me to remove one side. This got me curious from a general plumbing perspective. If you have to fit a pipe into a fixed space with a connector, it seems like you would have to tighten the union all the way on one side, insert the otherside and thread back the otherway. So if you had six threads on one side, when you loosen that side and connect to the otherside you would have 3 threads on each.
What's the guideline/rule of thumb when doing something like this?
I was removing the backflow preventer in preparation for winter. The unit is a series of components and union joints. Whenever I turned one piece to loosen, the other side would tighten. I was able to remove the device by tightening one of the union pipes a good amount, allowing me to remove one side. This got me curious from a general plumbing perspective. If you have to fit a pipe into a fixed space with a connector, it seems like you would have to tighten the union all the way on one side, insert the otherside and thread back the otherway. So if you had six threads on one side, when you loosen that side and connect to the otherside you would have 3 threads on each.
What's the guideline/rule of thumb when doing something like this?