Shoot me a good address and I will get you a couple inline pressure gauges to use.
I place one in the preconnect and the other at the inlet of the nozzle. Bring your static pressure up to 100psi and make sure all the gauges on the panel and those installed are reading within 5psi. We commonly see panel gauges way off because they never get tested so we never know when they're off.
Then when flowing water, assuming your pumping 150 on the #1 discharge. If the gauge in the preconnect reads 120, then your losing 30psi of loss before the pressure even gets to the hose.
Next read the pressure at the nozzle. If it reads 100 psi, then you now know the "measured" loss in the hose, which for this crude example, is 20psi of loss, yet most folks would take the discharge pressure of 150 and subrtract the nozzle pressure and insist the hose FL is 50 instead of using the actual hose inlet pressure of 120. They just fail to take into account the plumbing.
Remeber that as the flow goes up, so too with the FL, expenentialy.
Do you have a truck scale near by? Any place with a truck scale might let you put the pumper on the scale, weigh it full then flow water for a given time, then do the math on the weight after flowing. Its crude but it will tell you flow. The problem with that is it wont tell you where the problems are.
I feel your pain on no one listening. The FL numbers we see in some brands of hose is criminal. Not even close to the forumlas.
Another option is if you have hydrants in your area you can use city funds to get a flow meter to "TEST" the hydrants. Then once they buy into that you will have a flow meter to use for anything else you want to test.
And the old seet of the pants as to how long it takes to drain the tank with the handline gets you close and I have had some argue that it was one number until they were blue in the face only to confused when I asked how much water was still in the hose, plumping and pump before they shut down the pump? They just dont seem to understand all the variables in between the tank and their nozzles.
Dont get discouraged because even after showing people with flow meters and pressure guages I have been accused of "rigging" the flowmeter to show poor numbers for their stuff.
Its a week position at best but some people just arent open to the truth.
When Bobby Halton was the Training Chief in Albuqerque they were flowing 75 gpm, not 150+ as they thought. What seperates the leaders from the followers in this business is what they do with that kind of information. Chief Halton ended up flow testing EVERYTHING and made changes to ensure they were getting the flows they expected. The followers just ignore the facts. Those are the ones that scare the hell out of me.
I have been trying to get anyone to listen when I say that we don't KNOW for sure what we are getting from the pumpers.
I have asked for flow meters and in line pressure gauges, but I get the "Budget" response. I'm now trying to get containers to clock the flow against, but today I was out running the rig by myself. There is not a lot of interest in getting real numbers right now.
PS I did find the name brand of the 1.75 inch hose that we run on our attack lines (Key 800) and got the reported friction loss from the PDF file on your website. Thanks for that info.
Now I'm getting "It can't be that high, the nozzles are flowing what they are supposed to, yada".
Is there a source for friction loss in various makers of 1.5 and 1.75 hose? I am trying to get real numbers for our discharges and crosslays. I don't have access to flow meters or in-line pressure gages and when I used a hydrant defuser attached to a Blitz fire, I got an unbelievable psi number
If you have some time I would like to discuss with you some issues about fire flows and why we need to up to gpm on attack lines. I am doing this as a project for my instructor 1 class and would like some input if you have a free moment.
Thanks for clearing up some of the 'vindicator' issues. Here in Canada we use mostly fog nozzles, but I don't want to start that debate!
I agree that we're not getting enough water on most fires with our current nozzle. We've been lucky, no one has ever got hurt due to a lack of GPM. But the day is coming...you can't keep increasing fire load in a residence and keep the same amount of GPM flowing that worked 40 years ago!
Take care, thanks again.
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