Tube OD [mm] Nominal pressure [bar] L 6, 8, 10 500 L 12, 15, 18 400 L 22, 28, 35, 42 250 S 6, 8, 10 800 S 12, 14, 16 630 S 20, 25, 30, 38 420 1.3 Union nuts: SERIE L (light gauge) SERIE S (heavy gauge) [...] nut 6 8 10 12 15 18 22 28 35 42 M 12 x 1.5 M 14 x 1.5 M 16 x 1.5 M 18 x 1.5 M 22 x 1.5 M 26 x 1.5 M 30 x 2 M 36 x 2 M 45 x 2 M 52 x 2 6 8 10 12 14 16 20 25 30 38 M 14 x 1.5 M 16 x 1.5 M 18 x 1.5 M 20 x 1