Similar to CG-135 flange but with the mating end of the flange having a precision formed o-ring groove instead of being ground. Joint provides a grease-free vacuum tight seal when used with the CG-139 clamp. O-ring is included with each flange and can be ordered separately, see CG-305.

Item Number	Item Description	PQ
CG-138-01	32mm O-Ring Flat Flange, Tube ID: 27mm, Tube OD: 32mm, O-Ring Size 222	EACH
CG-138-02	57mm O-Ring Flat Flange, Tube ID: 52mm, Tube OD: 57mm, O-Ring Size 331	EACH
CG-138-03	80mm O-Ring Flat Flange, Tube ID: 75mm, Tube OD: 80mm, O-Ring Size 339	EACH
CG-138-04	4.5in O-Ring Flat Flange, Tube ID: 99mm, Tube OD: 105mm, O-Ring Size 348	EACH
CG-138-05	5.5in O-Ring Flat Flange, Tube ID: 130mm, Tube OD: 140mm, O-Ring Size 359	EACH