Hydraulic characteristics of the block with a series connection of shut-off and control valves and a non-adjustable multi-stage throttle

The unit is designed to reduce the pressure of water supplied to the fire extinguishing equipment (fire monitor and hand nozzles) from the reservoir pressure maintenance system. The pressure in the reservoir pressure maintenance system is 15-25 MPa. The pressure at the inlet to the fire extinguishing equipment is 0.7-1.0 MPa. With such differences and single-stage throttling, the water velocity can reach 200 m / s. The cause of the destruction of pipeline valves (TPA) is the velocity of the working medium (WM) in the restriction device (RD). The throttle is designed to obtain the required pressure and flow rate of WM, permissible values of WM speeds. The article presents the results of analytical, numerical and experimental determination of the resistance coefficient and throughput of the unit consisting of series-connected shut-off and control valves (ZRA) and a multi-stage unregulated throttle. Based on the research of throttles, stationary and mobile installations designed for fire extinguishing. The installation contains pressure reduction units for water supplied to fire extinguishing equipment (fire monitor and hand nozzles) from the reservoir pressure maintenance system (RPM). The greatest demand is for installations consisting of four pressure reduction units, one unit per hose. The design of the unit allows using river, Cenomanian, and bottom water supplied from the RPM system. The installation is connected to the RPM system using a quick-release coupling. The installation does not require a complex control system, additional safety devices, is easy to connect and operate, has free access to controls and visual control of operation. The installation is supplied on a vehicle trailer or in a stationary version.