Petrotrim Services provides the "NEW" style Body Bushing.
Some other companies provide the "OLD" style Body Bushing.
Below is the difference between the two different styles, NEW vs. OLD.
The new Body Bushing is designed to overcome the following problems.
1) Eliminate pressure trapping in the valve cavity when the gate is either fully open or closed.
2) Eliminate the tendency for the Seat Ring and Body Bushing to seal on the pressure side of the gate. (Upstream sealing). This effect increases the force to move the gate.
In most cases the Teflon Seal Ring is the same one used on the Stellite Seat Ring.