Detailed Product Description

1. Stopper The stopper on top can be made from glass or Teflon. It is imperative that it fits tightly, so that the solution does not leak out when the separatory funnel is inverted. If a ground glass joint does not fit perfectly, a minute amount of grease is applied to the upper part of the joint to get a better seal. The stopper has to be removed when draining the lower layer. If the stopper were not removed, a vacuum will build up above the liquid part and prevent the solution from draining. After some time, the vacuum will suck air in (from the stem) and the phases will mix again. 2. Stopcock plug The stopcock plugs can be made from glass (left side) or Teflon (right side). It is important to have a good seal here as well. Again, a very small amount of grease can be applied to the glass plugs (shown on the left) to improve the seal and allow for better movement of the plug. The grease should be used sparingly, because it will clog up the hole in the plug! The glass plug has to be held in place with a metal clip. Teflon plugs usually possess a thread (some glass manufacturers offer those version for glass plugs as well), which allows to place a nut on it to hold it in place. Teflon plugs should not be lubricated! In order to find out which plug is needed, the glass joint has to be examined. Glass stopcocks require a ground glass joint (looks milky if clean and is rough on the inside). Teflon stopcocks use a polished joint (clear). Do not attempt to fit a glass stopcock into a teflon joint! The slopes on the plugs are slightly different and the joint will break!