The PD series plugs are designed for use on flared JIC fittings and will seal low-pressure requirements with light finger tightening. May be used on 37 degrees flare fittings without gaskets. : : B: 1.06, C: 2.47, D:.38, P NTUBE IN: 1-1/2, TOFITTHRSZ: 1-7/8-12.