Why Does It Always Have to be Done That Way?
Myth 9: The nozzle pressure for a smooth bore tip on a handline should be 50 psi. Pressures higher than this will produce a broken stream as well as a handline that is hard to control.
Reality: I’m not quite sure where this myth came from, I know it’s been around since the turn of the last century. Smooth bore tip nozzles are rated so a specific size will flow X amount of GPM at a 50 pound nozzle pressure. Successful handlines have been used with nozzle pressures reaching 150 psi. Are these high flowing lines hard to control? Standing up, yes. The key is to get on the hose in either the crouched or sitting position, thus allowing the nozzle reaction to be directed into the ground. The higher pressure smooth bore handlines are more than likely going to be used in an exterior large flow attack versus an interior attack.
500 GPM is being delivered through a 1-3/8” tip at 80# NP