Posted By James Albert a fluid mechanics question... we intend to take our fire hose to say 'x' m height. what will be the pressure at the hose end at this height when water is pumped at 'y' bar pressure. what will be the nozzle reaction and what weight of water will act downwards? if someone can explain with some formulas and real values i will be grateful.

Posted By Brian Dawson Why not convert bars to head of water. 1 bar is equivalent to 401.65 inches of water. That should be a starting point.

Posted By Robert K Lewis James I shall revert to my chem eng days and as an engineer ask the following questions 1) Will the hose be taken up vertically or on an incline. 2) If an incline at what angle 3) Is it a new or old hose 4) In what direction is the hose nozzle pointed, as a vector to a vertical line. 5) Is it to discharge into open space or is there a nearby building face. 6) At what angle to such face will the water strike. As a manager I would say that you are asking the managerial questions. Some years ago the IChemE magazine had a satire on the Manager in a balloon basket and an engineer - see if you can find it. The real answer could no doubt be calculated by people like Frank but I am only good at designing chemical plant. PS Do not forget the precise lay of the hose on the ground before it commences the rise to x feet will also affect the calculation. PPS Most will have empirical tables for this as it is quicker. Bob

Posted By John Lewis From a non-technical, relying on experience viewpoint, the water issuing forth at the top is always less than you expect. Managers rarely realise that when you ask for X booster pump. John

Posted By Robert K Lewis For those interested the story of the man in a balloon is something like this: THE LOST BALLOONIST A man was hot air ballooning across the English countryside and was becoming perplexed because he was lost and there were no obvious landmarks to be seen. Inspiration strikes "I will descend from these heights and see if I can find out where I am" At the 100 foot level he spotted a lone figure walking the landscape. "Hello" he called. The walker looked around him in a startled fashion and suddenly realised it was a voice from above. "Hello" he called back in an uncertain manner. "Can you help me?" "Possibly, what do you want?" "Where am I? I have been drifting around for hours". "Ah" said the man "You are currently suspended in a basket attached to a large spherical object constructed of cloth of some description which is held in a state of buoyancy by large quantities of hot air. This air is heated to temperature by means of propane-fired gas burners." "I see that you are an Engineer" "How" he asked? "Well you have made a series of detailed statements about matters so specific that nobody really understands what you are saying. They help nobody and least of all me when you should have realised that what I was asking is how to find the route I should be on when I do not know where I am to start with" "I see that you then are a manager," replied the walker. "How do you know that?" "You descend from dizzy heights and call down to people below asking them imprecise questions with minimum information and expecting them to provide accurate answers but in the form in which you want them. You think that our time is totally yours and expect us to read your mind in order to service your needs, and thus achieve your goals".