Threaded pipe

Such threads are needed where the sealant would contaminate or react with the media inside the piping, e.g., oxygen service.

Due to the wedging effect of the tapered thread, extreme care must be used to avoid overtightening the joint.

The overstressed female fitting may split days, weeks, or even years after initial installation.

The nominal diameter is achieved some small distance (the "gauge length") from the end of the pipe.

Instead, an O-ring seated between the shoulder of the male pipe section and an interior surface on the female, provides the seal.