Quick Coupling: 1) Type: A, B, C, D, E, F, DC, and DP; 2) Size ... 2-1/2", 3", 4",5"&6 brass quick Couplings are used in a wide variety of applications for petroleum handling, chemical processing ... handling, agricultural, and water, etc. 1) Material: brass 2) Type: A, B, C, D, E, F, DC, and DP.3) ... Smooth face of groove and great resistance to vibration. 5) P. S. We are the qualified member of NFPA. Brass ...