Manual fire monitors are widelyused in marine, offshore, industrial and many other corrosive environments to stop unwanted fires.Fixed Monitors spend most of their lives stationary. Howeverwhen unwanted fires are perceived they can frequently be the only practical wayof applying foam or water to distinguish fire. Although simple in principle, fire monitorsare sophisticated engineering pieces of work designed to deliver a preciseperformance after long periods of inactive. Just like another engineeringchallenge the design of a fire monitor can take many arrangements depending onthe exact hazard it is anticipated to protect and the mechanism and techniqueof operation the designer uses to complete the final layout.
When designing a fire monitorthe designer must balance performance, operational life and ease of use bearingin mind the cost. It is vital thus, that monitors are robust and will have a longservice life, even under harsh conditions. Fixed fire monitors are often found anywherewhere there are considerable Class B fire risks whereas mobile or portable firemonitors are frequently utilised to safeguard various risks by moving themonitors around the site. Almost all industrial fire hazards are subjectto fire monitor protection, however some of the more popular applications mayinclude; refineries, chemical plants, helicopter landing pads, fuel distributiondepots and process plants etc… Although most fire monitors are permanently securedto pipework and designed to distinguish particular installations, in certaincircumstances monitors are mounted on trailers that can be moved from one fire hazardto another. But mobile monitors need a water supply, and usually this is deliveredby hoses or portable pumps. The jet reaction force for a portable fire monitorcan differ from few kg, for small ground monitor to over a tonne for largertrailer-mounted units. Portable monitors must be secured so that it cannot moveonce the full water flow andpressure is applied. The design of pump pipes that make up a monitor iscritical as they serve several functions.
They contain water or foam while permittingthe jet to be moved in both the vertical and horizontal planes, the pipes must havegood strength to resist pressure and reaction forces produced by the water andthey must be robust to accommodate the mounting of further items such aslevers, nozzles and hydraulic actuators etc.; all of this must be accomplishedwith a design that is cost effective, has a tolerable pressure loss, willresist corrosion and is not heavy. The design of a monitor is a negotiationbetween cost, weight and performance.