Internally pressurized seals

A method of thermally stabilizing an internally pressurized seal having a first seal ring mounted in fixed axial and rotational relationship and sealed with respect to one of a pair of relatively rotatable components, and a second seal ring that is axially moveable but fixed rotationally and sealed with respect to the other of the pair of relatively rotatably components, the second seal ring being urged resiliently towards the first seal ring so that a radial sealing face of the first seal ring engages a radial sealing face of the second seal ring, a process chamber being formed at an inboard side of the first and the second seal rings, the process chamber opening to outside of the first and the second seal rings, and a barrier chamber being provided at an outboard side of the first and the second seal rings, the barrier chamber opening to inside of the first and the second seal rings, the method comprising the steps of:

• ensuring that heat transfer from a process fluid in the process chamber to the first and the second seal rings predominantly occurs at outer regions of the first and the second seal rings adjacent the sealing faces;
• and
• ensuring that heat transfer between the first and the second seal rings and a barrier fluid predominantly occurs at radially extending faces of the first and the second seal rings adjacent their sealing faces.