With more folks moving to fabric 4 and 5-inch LDH it is still important to be aware of the maximum operating pressures of appliances and Storz couplings used in your LDH system. While it probably is very rare that we would pump that new 300 psi rated fabric 5-inch LDH at 300 psi, if we do....then there is a good chance that we are over-pressurizing some other system component. The good news is that we generally pump LDH at pressures under 200 psi....but at the big fire where folks are screaming for more pressure in the relay or to the aerial tower....be mindful of your devices and be sure your system relief valves are set to protect those devices and the hose.