pack a gate valve under pressure

[agattt]

If a gate valve is shut (closed) can the packing be replaced around the stem by removing the nut around the stem while there is Pressure in the line?

Thanks.

[SewerRatz]

If the gate valve has a packing nut like the one pictured here yes you can do it since there is the bonnet retaining the stem in place for you.

[agattt]

Thank you for your reply.

Yes, my valve looks like that. The non packing bolt is square not hexagonal. It looks like I will need to take off the handle to pull the packing bolt off enough to replace the packing.

thanks.

[hj]

You can repack the stem with the valve all the way open or all the way closed. It will only leak when it is partially open or closed. Usually the packing nut only has to be tightened to stop a leak, however.

[agattt]

I close or open it when I go away. It is the house main. While tightening the nut has helped it also makes it harder to open or close. Eventually I want to replace it with a lever ball valve but not eager to spend the $ right now. If I can change the packing with it off then I don't have to get the water turned off at the street.