Tubing sealers, whether hand held or desk mounted, heat seal liquid filled plastic tubing on command to develop sealed liquid filled easily separable segments serially attached to one another. The sealer generates a source of RF energy to heat seal the plastic tubing on placement of the tubing between a fixed jaw and a tubing compressing moveable ground jaw. The moveable ground jaw serves as a heat sink to dissipate heat and prevents a heat buildup during rapid repetitive operation of the sealer. The configuration of the moveable ground jaw coming in contact with the tubing primarily, but in combination with the degree of compression of the tubing and the RF power applied, controls both the integrity of the seal and the ease with which the sealed segments of tubing can be separated from one another.