A seal assembly capable of low temperature service is disclosed. It
features upper and lower metallic backup rings that are specially shaped
to act as a spring to keep the sidewalls of such rings in contact with
the inside and outside surfaces to be sealed to prevent extrusion of the
seal material even in low temperature situations. Inner and outer grooves
are provided. O-ring seals, used for the ID of the seal, are manufactured
to have a slightly greater diameter than the groove into which they will
be installed. The greater length provides stored energy to promote
sealing functionality in cold temperature situations. The O-rings used
for the OD of the seal are manufactured to have a slightly smaller
diameter than the groove into which they will be installed. The shorter
length provides stored energy to promote sealing functionality in cold
temperature situations.