The 80 series is has a special flare structure made up of flare-type hybrid tube fittings that make use of an inner ring. A ring is inserted into the inner diameter of the flared tube to enhance both pull-out and leak resistance. Under the special flare structure, the inner portion of the end is trimmed significantly such that the flare end becomes flat when the nut is tightened. Doing so creates a structure that does not accumulate contaminants, while improving the liquid displacement characteristics. At the same time, pressure loss is reduced with the flat inner diameter. With the threaded part on the outer circumference of the tube, the 80 series realizes a compact size that is up to 36% smaller than that of the 60 series. Piping can be easily fastened in place with the mounting hole on the tube fitting body.