... petroleum handling, chemical processing, dry bulk handling, agricultural, and water, etc.Adaptor x Female NPT/BSPT Standard: ... 1) Precisely machined for accurate fit, join fast and save effort2) Recess holds gasket firmly in place assuring ... proper placement,3) Smooth face of groove and great resistance to vibration.4) Size:1/2", ... 10) We are qualified member of NFPA. quick connect hose coupling