Shutoff valve care and other questions

Hello,

I came across this forum while going through a plumbing remodel, and I have found it very informative.

I wonder if someone could answer a few questions I have.

I recently finished up a repipe. This project started when I discovered that my shutoff valves were not functioning correctly and I could not shut off my water. After noticing peoples attitudes about polybutylene pipes, I decided that I did not want was was essentially an unsupportable system. This house is on its third piping system now.

Anyway, how should I take care of the new shutoff valves? Should I open them up all the way or only partially? Will one or the other cause damage over time? I used to keep the valves opened just enough to get decent water pressure, and I wonder if that caused issues with buildup or something.

While the walls were open, I took a good look at some of the old fixtures. They were completely covered in green scale and, on the hot water side, white powder. The white powder completely covered the connector and was growing up the old pipe. What is this stuff? I've also noticed this white powder forming on the fixtures at work, and the office building almost brand new.

Valves should be fully open.

Unless they are ball valves, I was always taught to fully open valves and then to screw back clockwise 1/4 turn.

Stops them seizing and leaking.

Ian Gills said:

Unless they are ball valves, I was always taught to fully open valves and then to screw back clockwise 1/4 turn.

Stops them seizing and leaking.

Click to expand...

You mean gate valves?

Ahh, more plumbing controversies... To fully open valves or not. When will it ever end¿¿¿

The company I work for says to turn 'em back a smidge to keep them from seizing as well. These are not 1/4 turn valves but multi turn.

kingsotall said:

Ahh, more plumbing controversies... To fully open valves or not. When will it ever end¿¿¿

The company I work for says to turn 'em back a smidge to keep them from seizing as well. These are not 1/4 turn valves but multi turn.

Click to expand...

I was always told on gate valves you go to full open and then back a quarter turn, this way if the gate does seize on the stem, then you can turn the valve in both directions to break it free.

kingsotall said:

Ahh, more plumbing controversies... To fully open valves or not. When will it ever end¿¿¿

The company I work for says to turn 'em back a smidge to keep them from seizing as well. These are not 1/4 turn valves but multi turn.

Click to expand...

And then you have to tighten the packing nut,all the way open on multi turn
valves compresses the packing.so you don`t have that little drip.And even then you
still have to give the packing nut a little turn.But then that was the we were told to do it.

Oh, you guys went to the same school as my guys. Forgot about that tighten the packing nut, even on one right outta the package.