You will not lose any pressure with the 3" diameter hose
Camlock Male Diameter Sizes: 5" (Plug)
3" Aluminum Female Camlock To Female Pipe Adapter
Fully lined with rubber on the inside
NH/NST = National Hose/ National Standard Thread
1.5" NST (NH) Male Hose x 1.5" NPSH Male Pipe Adapter DMH15F15F You will not lose anyChange Threads From 1. 5" NST (NH) Fire Hose To 1. 5" NPSH Pipe Hex Simply screw it on, and you're ready to go. The NST (NH) side of the adapter will allow you to connect the female end of your fire hose. The NPSH side of the adapter can hook into NPSH, PVC, NPS, NPSM, NPSC, IPS, IPSM, IPT, SIPT, MIP, MPT. Specifications 1. 5" NST (NH) Male x 1. 5" NPSH Male Full Brass NST (NH) National Standard Thread (National Hose) NPSH National Pipe Straight Hose