| Was the stopcock originally glass? Glass stopcocks are made in one taper, and most PTFE ones are a different taper, so they are not interchangable.
I have seen a few odd sized PTFE ones, and a few companies may have made PTFE ones that fit into glass stopcock joints, but they are very hard to
find and rare. Glass ones come a few standard sizes, like #2 (typically found on 30 up to 500 ml sep funnels) and #4 (typically found on 500 ml and
larger sep funnels) but there are smaller and larger ones out there. Teflon ones come in similar sizes, but are a different angle, with a 2, 4, and
6 size, but not the same as the glass ones. These are all the simple straight bore ones, when you get to three way or vacuum stopcocks, there are
many more "standards", so it is very hard to match them. |
