What are the common standards for threaded flanges?

　　To introduce the standard of threaded flange, we should first know some common quantities of threaded flange, such as nominal diameter DN, steel pipe outer diameter A, and some connecting dimensions D, center diameter K of bolt hole, bolt hole diameter L, bolt hole number n, threaded Th, flange thickness C, flange neck N, R, flange height H, theoretical weight kg, pipe thread specifications Rc, Rp or NPT. The unit is in inches.

　　Threaded Flanges DN is 10 mm, A is 17.2 mm, D is 90 mm, K is 60 mm, L is 14 mm, n is 4, Th is M12, C is 14 mm, N is 30 mm, R is 3 mm, H is 22 mm, weight is 0.64 kg, specifications are 3/8 inches;

　　1/2" 304 Female NPT Stainless Steel Threaded Flange DN is 15 mm, A is 21.3 mm, D is 95 mm, K is 65 mm, L is 14 mm, n is 4, Th is M12, C is 14 mm, N is 35 mm, R is 3 mm, H is 22 mm, weight is 0.71 kg, specification is 1/2 inch;

　　Threaded Flanges DN is 20 mm, A is 26.9 mm, D is 105 mm, K is 75 mm, L is 14 mm, n is 4, Th is M12, C is 16 mm, N is 45 mm, R is 4 mm, H is 26 mm, weight is 1.02 kg, specifications are 3/4 inches;

　　Threaded Flanges DN is 25 mm, then A is 33.7 mm, D is 115 mm, K is 85 mm, L is 14 mm, n is 4, Th is M12, C is 16 mm, N is 52 mm, R is 4 mm, H is 28 mm, weight is 1.23 kg, specification is 1 inch; DN is 32 mm, then A is 42.4 mm, D is 140 mm, K is 100 mm, L is 18 mm, n is 4, Th is M16, C is 18 mm, N is 60 mm, R is 30 mm, weight is 1.96 kg, specification is 11 inches;

　　Threaded Flanges DN is 40 mm, A is 48.3 mm, D is 150 mm, K is 110 mm, L is 18 mm, n is 4, Th is M16, C is 18 mm, N is 70 mm, R is 5 mm, H is 32 mm, weight is 2.31 kg, specifications are 11/2 inches;

　　Threaded Flanges DN is 50 mm, A is 60.3 mm, D is 165 mm, K is 125 mm, L is 18 mm, n is 4, Th is M16, C is 20 mm, N is 84 mm, R is 5 mm, H is 34 mm, weight is 3.04 kg, specification is 2 inches.