# Thread: What PSI do yall use?

1. ## What PSI do yall use?

I was just curious about what PSI yall tipically use on a 1.5 or 1 3/4 handline and what yall usually use on a booster reel hose?

2. It all depends on your setup. Where I'm at we usually use a fog nozzle as our primary attack with 1 3/4" line. As a rule of thumb I try to set everything up to where the noozleman will have a 100 psi at the tip (50 psi for a smooth bore), but the noozleman can always ask for more or less as he feels he needs. Since our standard is a 200 ft preconnect our standard is 150 psi at the pump, yes I realize this is a little below 100 psi at the noozle but it took a long time for our standard to get this high. This is only a rule of thumb as every fire is different. On the one department I run for that uses 1 1/2" the pressure is set at 200 and we go from there. It should be noted that for these noozles to function correctly they need 100 psi at the tip. As booster hoses go the only thing we use them for is brush fires and such and the pressure is usually set as needed to overcome friciton loss and depending on the fire. We never use them for anything like a structure or car fires. Friciton loss is the main factor I use to determine what pressure I set at the pump.

3. 200' 1 3/4 with smoothbore 140 psi for 185 GPM

200' 1 3/4 with TFT 190 for 185 GPM

300' 1 3/4 with smoothbore 185 psi for 185 GPM

1" forestry, usually 200 or adjust as needed for trash, brush, etc..

4. how about nozzle reaction?
forse on nozzle man.
stander nozzle pressure is 100 psi at tip.
so 125 gpm = 66 nozzle reaction.
250 gpm = 126 n.r. at 100 tip psi
smove tip @ 50 psi 15/16 is 66 n.r. 185 gpm

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The day that I stop learning about the fire service is the day I quit!

5. My dept's standard is;

1 3/4" and 2" lines w/ TFT intitial pressure is 150 PSI and then adjusted accordingly.

2" line w/ smoothbore initial pressure is 100 PSI and also adjusted accordingly.

On our 5" supply, the initial pressure is 40 PSI.

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6. Our Dept. SOP calls for 170 psi for our 1 3/4" preconnects, which are either 150 or 200 feet long. This was determined using friction loss and nozzle requirements for 200' and the non-adjustable gallonage nozzle we have.

In real life, most officers want about 130 psi so they can get the lead through the inside of a house.

No real standards for our 1" booster line.

7. E.P.=N.P.+ F.L. + EL. +/-

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The day that I stop learning about the fire service is the day I quit!

8. 1" booster @ 30 gpm = 150 ep
1" booster @ 95 gpm = 300 ep

1-3/4" X 200' @ 120 gpm = 120 ep
1-3/4" X 200' @ 275 gpm = 300 ep

9. I work for LAFD and we use 75 psi NP
50 psi FL
for every 100' feet of 1-3/4 hose @ 250 gpm
we dont use 1' reels. We use 1' dbl jacketed hose

10. Larry Welle:
E.P.=N.P.+ F.L. + EL. +/-

What does F.L. mean to you?

I know most folks relate FL to the Hose, however, we are finding as much as 100-psi of FL in pre-connect plumbing. FL in my opinion should relate to each and every object that has water going through it, such as plumbing, hose, valves etc.

EP=NP+ All FL + EL

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Kirk Allen
First Strike Technologies, Inc

11. Pump panel gauge pressure at 210 on a 200 foot 1-3/4" handline with a Heavy Attack Vindicator nozzle flowing 250 g.p.m.

SM-20 fog nozzle on the same line at 240 gauge for 200 g.p.m.

15/16" Smooth bore on the same line at 150 gauge pressure for 185 g.p.m.

This applies to one engine only. The others are different due to major differences in the amount of friction loss within the truck's plumbing and the brand and age of the hose.

You have to flow test each hose/nozzle setup to get true readings. The solid bore knob is easy, just use a pitot gauge. The SM-20 & Vindicator require a calibrated flowmeter. We test the bore first and then use it as a calibration check on the flowmeter.

Don't trust formulas & charts (except for the
solid bore tip flow) there are no places in the formulas for the variables caused by hose construction & plumbing. You have to add them to the total FL, like K.E.A. said. Do not trust the charts from any nozzle manufacturers literature to be accurate with your equipment. They can only give one test and you can bet that it will be the best one. DO THE TEST YOURSELF.

Sorry to edit. I need grammar check to go with the spell checker.

[This message has been edited by DD (edited 03-11-2001).]

12. This is a pet peeve of mine. We run 150' and 200' 1 3/4" preconnects w/TFT automatic adjustable nozzles. They are usually left in the 200 GPM position. Most of the guys pump them at around 120-130 psi. So, the Chiefs bought us bigger hose and new nozzles so we can flow less water than the old 1 1/2"! And we get to build up our muscle by dragging the bigger hose.
So few guys understand (or care) that they are only flowing 110-130 GPM. We have so few fires of more than one room nobody notices the problem.
Of course, the reason why they are pumped so low is we run 3 man engine companies. With the boss carrying tools and the TIC (if he can), the firefighter has his hands full controlling the line by himself. Boy, I'd love to go back to 1 1/2"!

13. gunnyv, can I have some clarification on what you said about the TFT being left in the 200 gpm position. Automatics have a flow range not an actual selection for the flow. It is based on what is pumped to it.

14. We recently purchase a new low friction lose hose to replace our High Combat 1 3/4" lines. With this on our Pierce's we have been able to cut our friction loss amazingly. We didn't believe we could get this reduced friction loss but tested it on each of our units to account for the pre-piping. We run 200' of this line on a pre-connect with a smooth-bore stacked tip nozzle (1" and 1 1/8"). This is giving us 200 GPM @ 110 Engine Discharge Pressure or 250 GPM @ 160 Engine Discharge on 1 3/4" lines. Our Truck uses the same hose with a 15/16" tip and is getting the 185 GPM @ 105 Engine Discharge Pressure. I can't think of the name of this hose off the top of my head but if you are interested you can email me.

15. onycs: Does Snap-tite Ponn Conquest sound familiar? If its not Conquest let me know, I would love to try some in future testing.

In our testing all over the country we have found the conquest to provide the best flow with the least amount of friction loss across the board.

Before you start Larry, so there is no confusion, I dont concern my self with the ID of the hose!

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Kirk Allen
First Strike Technologies, Inc

16. Yeah Conquest is the stuff. It is great hose. We just got the chief to order 600' of 1.75" in addition to the 400' we tested. On our new engine we are also going to try and get the conquest in our 2.5" or 3" (still some debate on 2.5" or 3") In all your testing is there really any difference in the standard LDH 5" compared to conquest 5" LDH - I heard they do make it in 5"?

17. What about pressure relief valve settings? We use 1 3/4" hose with preconnects of 200' and used to keep the relief valve set at 120 psi. We have now switched to a setting of 200 psi as standard. A lot of the guys think this is too high to be safe with our 2 and 3 man companies. They also think that the operator will not remember to re-adjust the setting once on the scene. Any comments?

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18. It is a good point to check with the nozzleman for adequate pressure. He is the one that has to fight the fire so if he wants more or less then he's the boss. Knowing standard pressures is good but not the law. I recently was training with a fellow firefighter getting ready for an engineer's test. He read all the books on pumping he could find. We connected 50' of 1 3/4" line and charged the line. Well he read that the FL on 100 feet of 1 3/4" was 64psi. He never bothered to look at me and see how I was doing with the line. After he cranked it up and my feet left the ground I shut the line down. He swore that the gauges were wrong because he read the friciton loss correctly. I told him he was incorrect but he refused to listen. 8 hours later he informed me he had misread the book. It should have been 64psi for 200ft. That is the difference between book knowledge and truly knowing what you are doing.

19. We run 200ft preconnect 1 3/4 in. lines with akron turbojet constant gallonage nozzles set at 150gpm. To get this we run 170 psi at the pump.
I think the best thing is the new flow meters instead of pressure meters. You throttle up until you reach the desired gpms. You know the gpms you flow has to come out the other end. There is no figuring friction loss or any other calculations. We plan to spec these on our next pumper.

20. For 1-1/2 with set gallonage fog nozzle 100psi + 30lbs. friction loss per 100'

21. 180 GMP with a 100 PSI automatic nozzle 200 ft of 1.75 (that Is 1 3/4) Factoring in friction loss of the hose and the Engines Pre-Connected plumbing (that is a PUMPER) the pressure is 225 at the pump and the nozzle you fight fires with the 15/16 smooth bore with is a 50psi tip at 186GMP same hose same plumbing 175psi at the pump with .5% (that is 1/2%) Class A foam from the Foam Pro.

22. 180 gpm automatic nozzle at 100 psi for 200' of 1 3/4" line you should run around 180 psi engine discharge pressure. 225 is about 45 psi extra friction loss. Either your calculations are wrong or you have some lowsy pre-plumbing or bad hose. I would hate to be the nozzleman on the end of that hose. For 186 gpm 15/16" solid bore you should be around 135 psi engine discharge. Again that is a great deal of extra if you are at 175 psi. Just a thought.

I agree with the comment earlier though. Book knowledge can get you into trouble. It is important to understand hydraulics but you should also understand what your nozzleman needs to manuever the hose. A stream is only as good as it is manueverable. I usually start my guys out 10-30 psi lower than the hydraulic math says then increase it when they ask for it. This works great for our department.

Ron Sanders
Engineer/FF/EMT

23. Roger, you are right that the plumbing is poor on this rig, and you proved the point that no two rigs are the same; nor can you assume that both crosslays are plumbed the same. The point is, each pre-connect needs to be flow tested, the way it is done around here is a smooth bore and a pitot gauge the neighbors have a TFT flow meter the same hose and smoth bore on a crosslay on our Eng. 3 is pumped at 155 psi for 186 gpm. Take care of your crew and your rig STAY SAFE.

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