1. #1
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    Default Pumping - 4" hose as a main suction/feeder question

    I would like to tap into opinion's on the use of 4" hose as a main suction/feeder line for fire pumps.

    We are a very old midsized city (130K) with a diverse population with lots of fire potential. We have our typical old balloon construction housing, along with new construction, high-rises and some old industrial buildings left, along with many apartment complexes. We have seven front line engines and two reserves, along with a tower and a straight stick aerial. The straight stick doesn't have a pump.

    All of our front line pumps are two stage 2,000GPM, including the tower. One reserve is a 1750 and the other is 1500. All of our engines have 5" front suctions and a single side intake valve attached. We just switched over from a dual bed of 3" hose to a single 800' bed of 4" hose, as our main supply line.

    Our hydrant out put goes from very good, to just enough to supply one single hand line, depending on where you are in the city. Most of our hydrants have three ports, one steamer and two 2-1/2" connections, with a spattering of the older sections having 2-2-1/2" ports without the steamer connection.

    Here's the way our suction lines were set up:

    1-25' of 5" fabric suction hose pre-connected to the front suction in the front bin, with NST threads.
    2-25' sections of 3", one each in running board trays, one on each side of the engine.
    The hydrant gate was a mandatory item on the hydrant, every time we put one in operation.

    The new way:

    1-50' section of 4" in the front bin, disconnected, with Storz connections and adapters
    1-33' section of 4" stored in the side tray which could be used as a second feeder with Storz connections and adapters (actually this is kept there as a "make up" line for the 4" discharge line)
    The hydrant gates are being down graded to discretionary

    I've heard all the comments on the 4" hose as a discharge line. What I'm really interested in is the part of the equation between the hydrant and the pumper, as listed above. I ask opinions of engineers (OE's) who have been around the block a time or two.

    I will reserve my comments as not to tip my hand, or offer my opinion. I am all for change, if it is a change to actually make an improvement.

    Thank You.
    Last edited by SEMPERFI3; 11-02-2009 at 09:27 AM.

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    You have alot of info here, but I'll take a stab.

    You actually decreased efficiency by switching to 4" where you used to carry 5" on your front suctions for two reasons. One, its smaller diameter, two its longer. Both work against you, especially for high flows. Additionally, why you wouldnt keep your front suction line preconnected to the rig (unless the rig design doesnt allow for it) baffles me?

    Not sure what your exact question is, but as I read it its about how efficient your new setup for the intake lines is compared to your old one. The answer, not so much. Not being a veteran of the front suction but having one on our rig, I see anything over 25 feet overkill and anything less than 5" hose as undersized. Same should hold true for other intake lines, if you expect to be able to flow maximum efficiency when its necessary. You won;t see any difference unless you do flow testing. Without any flow meters, you can prove the difference by simply hooking up the old setup and comparing intake and discharge gauge readings as well as RPM and then hook up the new setup and record the readings. Flow out of your wagon pipe with an 1 1/2" or larger tip. If your gun has a pressure gauge, even better. Set it for the same pressure each time. The real numbers that you need to look at are the RPM and the Intake (residual) for each "test". The difference will be notable. My guess, higher RPM, lower residual for the 4", the opposite for the 5".

    I'd stick with the gate valves on both ports at all times, hooking a second 4" line into your pump will assuredly give you more water and may even double your capacity (situationally depending).

    Do you have LDH to 2 1/2" adapters to use the LDH hose on the smaller hydrant outlets?

    As far as your layout beds, you have the same effieiency essentially, twin 3's is almost identical to single 4" in flow effieiency and is only one line to lay or pick up. The down side is that unless you got attack grade 4", then you actually arent as capable as before, because your max pressure into the 4" lines would be 180 PSI were on 3" you were able to pump up to 250 or even 350 dependong on the brand of hose you had.
    Last edited by MG3610; 11-02-2009 at 05:46 PM.

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    hydrant gates are always a good idea, I'd still keep them as a necessity. By gating the hydrant this way you can take the initial 4 inch off the steamer if you don't have time to hook up the other hoses. It also lets you hook up additional lines without shutting down the hydrant if you need more water (assuming the hydrant can support it.).

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    Frankly, I don't think the change from dual 3 inch lines to a single 4 inch hose gained you a single thing. Two 3 inch lines have long been considered hydraulically equal to a single 4 inch line. If you gained anything, it is the speed in hooking up only one line over two. Secondly, switching your short lay suction lines to 4 inch from 5 inch handicaps your water supply when the engine is hooked to the hydrant.

    It is impossible to supply anything close to the rated capacity of your 2000 gallon per minute pumpers with a single lay of 4 inch hose. If you are stuck with 4 inch hose I would suggest that you supply your engines with a 4 way hydrant valve (as much as I despise them) and have the first in engine lay in and the second in engine reverse lay a second 4 inch line to the hydrant and then pump both lines. You might then come close to supplying capacity at a large fire. The 4 inch hose will be just fine for the bread and butter house fires when flows rarely ever near 1000 gpm.

    2000 gpm pumps need at least 5 inch hose, or maybe even 6 inch. I have never understood buying 1500 plus gpm pumps, and especially 2000 gpm pumps and then handicapping them with inadequate supply lines.
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    Default 4" soft sleeve hook-ups

    Several things raise their ugly heads in your description of supply set-ups on 2,000 gpm engines. First, many manufacturers treat front suctions like auxiliary intakes and do not minimize the elbows nor maximize the size of the waterways from the bumper to the pump intake manifold. Crawl under the rigs and examine the piping arrangements and sizes. Perform some tests using the side steamer intake and measure the maximum flow, then change to the front suction and see what sorts of restriction this causes for the engine.
    Second is the abandonment of the “Hydrant Dressing Practice” of attaching a gate valve to one outlet. If you are connected to a very good hydrant, this practice will allow the connection of a second engine to the hydrant without shutting down. Also, in the case of debris in the line blocking one intake, it will be possible to dump the rocks, snuff box lids and soda cans out of one line without shutting down the engine completely.

    Now to the question: Four inch LDH has a loss of around 100 psi per hundred at 2,000 gpm. Your 33 ft piece will loose 33 psi from the hydrant to the engine. Dual 3” lines each 25 ft long will have a loss of about 100 psi per hundred feet or a loss of 25 psi in 25 feet. (1,000 gpm per line) Either way the losses are very similar between the hydrant and the engine, provided you can reach the hydrant with the 25 ft sections. If you continue to dress the 3 headed hydrants and use both a 33 ft piece of 4” and parallel a 25 ft piece of 3”, the losses will be very close to 12 psi with the 4” line carrying 1350 gpm and the 3” line carrying 650 gpm. On hydrants supplied by 8” or smaller feeds, this dual line hook-up probably won’t make much difference, but the larger the main and the lower the initial pressure (static) on the hydrant the more significant will be the hookup practices. You may be able to get the correct amount of water into the engine, but sending it down the block using 4” lines becomes a bit of a challenge. Since 4” LDH has a loss of around 100 psi per 100 ft., you should expect to be able to move the full 2,000 gpm down the block only 200 feet before reaching the maximum capacity of both your engine and the test pressure of the LDH. With engines over 1250 gpm, one should seriously consider 5” or larger LDH. Using 5” LDH you should be able to relay 2,000 gpm slightly over 600 feet before reaching the 150 psi rating of your 2,000 gpm pumps.
    The previous three posters all had very valuable suggestions concerning your proposed changes in the hose used to supply the engines. Doing some controlled tests can't be over emphasized.

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    Quote Originally Posted by KuhShise View Post
    Several things raise their ugly heads in your description of supply set-ups on 2,000 gpm engines. First, many manufacturers treat front suctions like auxiliary intakes and do not minimize the elbows nor maximize the size of the waterways from the bumper to the pump intake manifold. Crawl under the rigs and examine the piping arrangements and sizes. Perform some tests using the side steamer intake and measure the maximum flow, then change to the front suction and see what sorts of restriction this causes for the engine.
    Second is the abandonment of the “Hydrant Dressing Practice” of attaching a gate valve to one outlet. If you are connected to a very good hydrant, this practice will allow the connection of a second engine to the hydrant without shutting down. Also, in the case of debris in the line blocking one intake, it will be possible to dump the rocks, snuff box lids and soda cans out of one line without shutting down the engine completely.

    Now to the question: Four inch LDH has a loss of around 100 psi per hundred at 2,000 gpm. Your 33 ft piece will loose 33 psi from the hydrant to the engine. Dual 3” lines each 25 ft long will have a loss of about 100 psi per hundred feet or a loss of 25 psi in 25 feet. (1,000 gpm per line) Either way the losses are very similar between the hydrant and the engine, provided you can reach the hydrant with the 25 ft sections. If you continue to dress the 3 headed hydrants and use both a 33 ft piece of 4” and parallel a 25 ft piece of 3”, the losses will be very close to 12 psi with the 4” line carrying 1350 gpm and the 3” line carrying 650 gpm. On hydrants supplied by 8” or smaller feeds, this dual line hook-up probably won’t make much difference, but the larger the main and the lower the initial pressure (static) on the hydrant the more significant will be the hookup practices. You may be able to get the correct amount of water into the engine, but sending it down the block using 4” lines becomes a bit of a challenge. Since 4” LDH has a loss of around 100 psi per 100 ft., you should expect to be able to move the full 2,000 gpm down the block only 200 feet before reaching the maximum capacity of both your engine and the test pressure of the LDH. With engines over 1250 gpm, one should seriously consider 5” or larger LDH. Using 5” LDH you should be able to relay 2,000 gpm slightly over 600 feet before reaching the 150 psi rating of your 2,000 gpm pumps.
    The previous three posters all had very valuable suggestions concerning your proposed changes in the hose used to supply the engines. Doing some controlled tests can't be over emphasized.
    Kuhshise,

    With regard to your comment about reaching your 150 PSI pump capacity limit, is that how you determine the distances you can move the 2000 GPM?

    I always understood the pump rating at draft with no gain of pressurized water to be increased substantially by a water source (read: good source) such that pressures well into the 180 PSI range (Max hose pressure for supply LDH) are easily achievable versus the 150 you refer to. Obviously, at draft and with the correct number of suction lines in the water 150 becomes more of a reality, but in hydrantville, I don't see why you use this figure (150) as a max.

    Am I missing something?

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    MG3610: I used a 50 psi supply pressure ( incoming) thus reaching about 200 psi discharge into the 4" hose. (absolute maximum with supply hose) and a friction loss of 100 psi per 100 ft, to get the 200 foot of distance from the relay pumper at the hydrant to the attack engine on the scene. For 5" supply line, I use a Q squared divided by 15 to estimate friction loss. This is about 25 psi per 100 ft or 150 psi loss between engines for a 600 ft lay. Assuming the attack engine would like 20 to 30 psi incoming, then thesupply engine must discharge around 180 psi or very close to the maximum normal discharge allowed for LDH. Also assuming a 30 psi incoming at the relay engine setting the net pump pressure at (180 - 30 = 150) so it would be at the pump design point for the 2,000 gpm pumps in the discussion.

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    Quote Originally Posted by KuhShise View Post
    MG3610: I used a 50 psi supply pressure ( incoming) thus reaching about 200 psi discharge into the 4" hose. (absolute maximum with supply hose) and a friction loss of 100 psi per 100 ft, to get the 200 foot of distance from the relay pumper at the hydrant to the attack engine on the scene. For 5" supply line, I use a Q squared divided by 15 to estimate friction loss. This is about 25 psi per 100 ft or 150 psi loss between engines for a 600 ft lay. Assuming the attack engine would like 20 to 30 psi incoming, then thesupply engine must discharge around 180 psi or very close to the maximum normal discharge allowed for LDH. Also assuming a 30 psi incoming at the relay engine setting the net pump pressure at (180 - 30 = 150) so it would be at the pump design point for the 2,000 gpm pumps in the discussion.
    I got ya, so for the sake of gauge readings we are looking at 180 on the gauge not 150 at the supply engine, right?

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    Right!!! Oh! I'm TOO SHORT !!! That's what the better half has been saying for 47 years.

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    Thanks for your replies. I wanted to give you just enough information so I could try to get a more non-bias opinion. I kind of tipped my hand though when I said I'm all for change, if it's for the better.

    I have been in the fire service for 32 years now, a driver for 28 years and I thought I missed something.....I thought a more slippery water had been invented and we didn't have to worry about friction loss any more.

    Over the years, my love of fire apparatus and being an "OE" kept me from ever wanting to be promoted. This along with being involved in the maintenance division, allowed me to have a say into what went on our rigs right down to the model air dryer we wanted. As I age now, I am still asked to be involved with the rigs and that will taper off too. As far as I know the hose loading changes we have made, were never discussed with any of the drivers.

    I have been and always will be a fan of two stage pumps, as I feel they are more efficient. About 20 years ago 1-3/4" line came into vogue, around here anyway, so we were conceivably going to be flowing at higher pressures. Our single stage pumps were screaming to provide those pressures to supply the 1-3/4" lines. With the higher RPS's, required with the single stage pumps, we also had allot of heat build up "dead heading" if the drivers didn't pay attention. The last item, the two stage will do the same job with allot less noise around the fire scene, due to the lower RPM's.

    The reason I was only asking about the suction is, we have purchased all this 4" supply hose and I know we are never going back or up grading to 5", so it's a dead issue. I feel I can still press to have the front suction issue at least addressed, as we still have those hoses laying around for now.

    When we had two 800' loads of 3" instead of a single load of 4" or 5", we went and tried flow meters on the front suction, instead of putting the flow meters on multiple lines. Flow meters are notoriously inaccurate, but our set up actually has worked pretty well for us over the years and when I performed the pump tests, they were always checked for accuracy.

    I really never paid much attention to the difference in the friction loss in 4" vs 5", because we never had any. The difference blew me away. It's like if your going to make the plunge to LDH why buy 4"?

    MG3610 is right on. I did a flow test on one of our medium flow hydrants and I found I could only get 900 gallons out of the 33' section of 4" suction and 1350GPM out of the 25' section of 5", this was with 10psi residual pressure, for each set up. On our best main (24" 80psi res) we were able to get 2350 with the 5" and 1,800 with the 4". In my opinion, the less flow and pressured hydrants will be causing us real problems in the future if we don't "dress the hydrant" as they say. In one memo we were told that the hydrant gate was going to be removed completely.....what are they thinking? A comment was made to me, "when do we ever pump over 1,000GPM anyway". My come back is, then lets buy 1,000 GPM midi pumpers and we'll save alot of $$$$!

    Also answering the question, I take exception to the fact that none of the front suctions are supposed to be pre connected. Along with this, we have to put additional adapters on before we can charge the hydrant. It may only be an extra minute or two, but that is an eternity when the guys are waiting at the other end for water. The 50' section is to be left un-coupled because they want you to use either the 33' or the 50' section in the bins, to possibly splice into the 100' length of 4", if you are leading out. They have now taken away our access to our 3" except for a couple of short lengths carried in the wells, to hook to a stand pipe. If you want to hook a second line to the hydrant, you have to put the gate on the 2-1/2" hydrant port and then another adapter and use 4"! One officer who I was showing was asking what we were doing hooking the 4' hose to the 2-1/2" port.

    nameless also had a good answer putting the hydrant gate on every time.

    FYRED UP had the best WTF are you doing come back. There is a side issue to our 2,000 GPM pumps. Waterous pumps up to 2,200 GPM are the same price as a 1,500 GPM, as they are basically the same pump. You have to pay for whatever discharges you want and you have to go thru the extra work to test them every year. Back in the 1990's some apparatus Mfg's were pushing the much cheaper, marginally capable engines in a much less expensive chassis. The engine would turn the 1,500GPM pump when new but when you get a few years on it, what then? Being a fan of a true heavy duty rig, with a large block engine and trans and everything else to match, I pushed to get the higher volume pumps, that were beyond the marginal engine's reach, just in case someone got a wild hair.

    KuhShise brought up the front suction piping and is also correct. When the LDH question first came up, I asked if we could just do away with the front suction, as it's far more efficient going in the side. To add insult to injury, some manufacturer's are crossing the piping over to the drive's side of the rig, about at the mid point near the transmission. This keeps the valve away from the DPF, as it gets so hot! With a 5" front suction, the most I could ever get was between 750 and 950 GPM at draft. I believe the only remaining saving grace to a front suction, is that it keeps the hose lay in line with the rig and it will keep some sort of lane open around the rigs. Coming off the side intake or discharge will immediately block the street. Large cities use this theory, as the new FDNY rigs have a front suction along with an LDH front and rear discharge. Chicago carries all that ugly LDH on the front bumper. Functional I guess , however it's butt ugly.

    The decision makers now in place, came on well after I was on the job and I consider most of them my friends. I however still have to be careful not to over step my bounds regardless of how flustrated I become.

    Thanks again to all, I may be old, but not dead yet!

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    Best thing you can do is get rid of that dang front suction! If you are looking for a connection in-line with the apparatus go to a rear suction instead. A front suction generally has to be plumbed into a downward facing ANSI flange on one of the pump's intake fittings behind the operator's panel. The sheer number of elbows and bends required to make it fit in, on, and under the apparatus make it a horrible way to bring water in.

    A rear intake generally runs a straight shot along the frame rail and then directly into the back of the same fitting. It's a longer run of pipe, but with almost no bends in the pipe the friction loss is minimal even at high flows.


    With regard to your initial question about changing hose, the question really comes down to which one of those suction lines that you were carrying got connected as a general rule. If it was the 5" on the front, then you took a step backward, if it was the 3" on the side, you took a huge leap forward.

    As for replacing the 3" in your hose bed with 4", you absolutely took a step forward there. Would 5" have been better? Sure. But you could also argue then that everyone should just get it over with and buy 6".

    My department ran 4" for all of our main supply and relay hose. Guess what we found? You know those 2.5" side ports on the hydrants? We would get maybe another 350 or so GPM out of those when we ran 2.5" hose from there to an intake. When we used an adapter and ran 4" from that same 2.5" hydrant nozzle we could get flows near 1000 GPM. Granted this is all dependent on the residual hydrant pressure, but you get the idea.

    Another thing we discovered: when you need to hook into an FDC you get better flow by running a single 4" than you could by running two 2.5" (I know you have been using 3", but again, you get the idea here). When you're pumping to the ladder pipe on your stick you can do the same thing, or if you really need big water run dual 4" lines. I'm not saying there's anything wrong with the way you guys were doing it previously, just trying to point out that sometimes a little bit of outside-the-box thinking can create a huge benefit.

    If there is one big advantage to standardizing on all 4" as opposed to keeping that 5" on the front it is that you will only need one kind of adapter for your LDH instead of having to carry adapters for both 4" and 5". At some point somebody would screw that up and delay getting water to the engine, and now you're stuck with an empty tank while somebody scratches their head over why the hose won't connect and then has to go get a different adapter.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    Quote Originally Posted by Johngagemn View Post

    You know those 2.5" side ports on the hydrants? We would get maybe another 350 or so GPM out of those when we ran 2.5" hose from there to an intake. When we used an adapter and ran 4" from that same 2.5" hydrant nozzle we could get flows near 1000 GPM. Granted this is all dependent on the residual hydrant pressure, but you get the idea.
    Now if you really want to make those gated inlets work, try this. And you have all the stuff you need to make it happen, right there where you work.

    Two 3-1/2 8-bolt elbows and a 3-1/2" valve. If you don't already have it, an 8-bolt flange in the bottom of the steamer inlet casting. Bolt one elbow to the steamer inlet, facing either forward or aft, whichever way you have the room. Bolt the valve to that elbow, with the valve PARALLEL to the frame/pump house skin panel. Bolt the other elbow to the free end of the valve, with the free end flange pointed out. Add whatever you need to adapt to hose line connections (we use 3"). Only two 90s plus the entrance into the steamer inlet in the whole thing. Now see how much water you can move through it!

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    Quote Originally Posted by chiefengineer11 View Post
    Now if you really want to make those gated inlets work, try this. And you have all the stuff you need to make it happen, right there where you work.

    Two 3-1/2 8-bolt elbows and a 3-1/2" valve. If you don't already have it, an 8-bolt flange in the bottom of the steamer inlet casting. Bolt one elbow to the steamer inlet, facing either forward or aft, whichever way you have the room. Bolt the valve to that elbow, with the valve PARALLEL to the frame/pump house skin panel. Bolt the other elbow to the free end of the valve, with the free end flange pointed out. Add whatever you need to adapt to hose line connections (we use 3"). Only two 90s plus the entrance into the steamer inlet in the whole thing. Now see how much water you can move through it!
    We did it even simpler than that. Just take the 4" and run it to one of your other main inlets. Now you've got zero restriction in the plumbing.

    By the by, we actually make both single and dual auxiliary suction manifolds that are designed to install in exactly the way you're talking about. They use a single 8-bolt elbow and the manifolds terminate in four bolt flanges that can accommodate an Elkhart or Akron suction valve. In most cases it is a relatively easy thing to retrofit to give yourself additional inlets.

    Now, if you REALLY want to go big or go home you can go with the pant-leg suction on your main inlet. There's nothing like dual 6" inlets on one side to be able to bring in big water. FDNY is using this configuration on the officer's side of their new pumpers. It allows them to draft 2000 GPM from one side of the truck.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    Quote Originally Posted by Johngagemn View Post
    We did it even simpler than that. Just take the 4" and run it to one of your other main inlets. Now you've got zero restriction in the plumbing.

    By the by, we actually make both single and dual auxiliary suction manifolds that are designed to install in exactly the way you're talking about. They use a single 8-bolt elbow and the manifolds terminate in four bolt flanges that can accommodate an Elkhart or Akron suction valve. In most cases it is a relatively easy thing to retrofit to give yourself additional inlets.

    Now, if you REALLY want to go big or go home you can go with the pant-leg suction on your main inlet. There's nothing like dual 6" inlets on one side to be able to bring in big water. FDNY is using this configuration on the officer's side of their new pumpers. It allows them to draft 2000 GPM from one side of the truck.
    We have the pantleg discharge on one of our engines. We have gone to Waterous valves exclusively because they are the only ones that open and close easily under our high hydrant pressures. Also, in the life of our '89 Quality/Duplex, I rebuilt one of the 3-1/2" pantleg valves about 10 years ago. About a month ago I did the first of our 2-1/2" full flow valves. Not too shabby. Very pricey valves, but when you look at it in terms of total cost of ownership (cost of periodic rebuilds plus downtime on the vehicle) over the life of the vehicle, it's actually a decent buy.

    I had been doing the plastic ball valves about once a year. Same valve with the steel ball lasts longer, but still doesn't to open and close well under pressure.

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    Quote Originally Posted by SEMPERFI3 View Post
    Thanks for your replies. I wanted to give you just enough information so I could try to get a more non-bias opinion. I kind of tipped my hand though when I said I'm all for change, if it's for the better.

    I have been in the fire service for 32 years now, a driver for 28 years and I thought I missed something.....I thought a more slippery water had been invented and we didn't have to worry about friction loss any more.

    Over the years, my love of fire apparatus and being an "OE" kept me from ever wanting to be promoted. This along with being involved in the maintenance division, allowed me to have a say into what went on our rigs right down to the model air dryer we wanted. As I age now, I am still asked to be involved with the rigs and that will taper off too. As far as I know the hose loading changes we have made, were never discussed with any of the drivers.

    I have been and always will be a fan of two stage pumps, as I feel they are more efficient. About 20 years ago 1-3/4" line came into vogue, around here anyway, so we were conceivably going to be flowing at higher pressures. Our single stage pumps were screaming to provide those pressures to supply the 1-3/4" lines. With the higher RPS's, required with the single stage pumps, we also had allot of heat build up "dead heading" if the drivers didn't pay attention. The last item, the two stage will do the same job with allot less noise around the fire scene, due to the lower RPM's.

    The reason I was only asking about the suction is, we have purchased all this 4" supply hose and I know we are never going back or up grading to 5", so it's a dead issue. I feel I can still press to have the front suction issue at least addressed, as we still have those hoses laying around for now.

    When we had two 800' loads of 3" instead of a single load of 4" or 5", we went and tried flow meters on the front suction, instead of putting the flow meters on multiple lines. Flow meters are notoriously inaccurate, but our set up actually has worked pretty well for us over the years and when I performed the pump tests, they were always checked for accuracy.

    I really never paid much attention to the difference in the friction loss in 4" vs 5", because we never had any. The difference blew me away. It's like if your going to make the plunge to LDH why buy 4"?

    MG3610 is right on. I did a flow test on one of our medium flow hydrants and I found I could only get 900 gallons out of the 33' section of 4" suction and 1350GPM out of the 25' section of 5", this was with 10psi residual pressure, for each set up. On our best main (24" 80psi res) we were able to get 2350 with the 5" and 1,800 with the 4". In my opinion, the less flow and pressured hydrants will be causing us real problems in the future if we don't "dress the hydrant" as they say. In one memo we were told that the hydrant gate was going to be removed completely.....what are they thinking? A comment was made to me, "when do we ever pump over 1,000GPM anyway". My come back is, then lets buy 1,000 GPM midi pumpers and we'll save alot of $$$$!

    Also answering the question, I take exception to the fact that none of the front suctions are supposed to be pre connected. Along with this, we have to put additional adapters on before we can charge the hydrant. It may only be an extra minute or two, but that is an eternity when the guys are waiting at the other end for water. The 50' section is to be left un-coupled because they want you to use either the 33' or the 50' section in the bins, to possibly splice into the 100' length of 4", if you are leading out. They have now taken away our access to our 3" except for a couple of short lengths carried in the wells, to hook to a stand pipe. If you want to hook a second line to the hydrant, you have to put the gate on the 2-1/2" hydrant port and then another adapter and use 4"! One officer who I was showing was asking what we were doing hooking the 4' hose to the 2-1/2" port.

    nameless also had a good answer putting the hydrant gate on every time.

    FYRED UP had the best WTF are you doing come back. There is a side issue to our 2,000 GPM pumps. Waterous pumps up to 2,200 GPM are the same price as a 1,500 GPM, as they are basically the same pump. You have to pay for whatever discharges you want and you have to go thru the extra work to test them every year. Back in the 1990's some apparatus Mfg's were pushing the much cheaper, marginally capable engines in a much less expensive chassis. The engine would turn the 1,500GPM pump when new but when you get a few years on it, what then? Being a fan of a true heavy duty rig, with a large block engine and trans and everything else to match, I pushed to get the higher volume pumps, that were beyond the marginal engine's reach, just in case someone got a wild hair.

    KuhShise brought up the front suction piping and is also correct. When the LDH question first came up, I asked if we could just do away with the front suction, as it's far more efficient going in the side. To add insult to injury, some manufacturer's are crossing the piping over to the drive's side of the rig, about at the mid point near the transmission. This keeps the valve away from the DPF, as it gets so hot! With a 5" front suction, the most I could ever get was between 750 and 950 GPM at draft. I believe the only remaining saving grace to a front suction, is that it keeps the hose lay in line with the rig and it will keep some sort of lane open around the rigs. Coming off the side intake or discharge will immediately block the street. Large cities use this theory, as the new FDNY rigs have a front suction along with an LDH front and rear discharge. Chicago carries all that ugly LDH on the front bumper. Functional I guess , however it's butt ugly.

    The decision makers now in place, came on well after I was on the job and I consider most of them my friends. I however still have to be careful not to over step my bounds regardless of how flustrated I become.

    Thanks again to all, I may be old, but not dead yet!
    You have some good insight. Stick around here and be a regular contributor.

    Did you try two 4" lines off a hydrant at all and figure out flow capabilities?

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    Quote Originally Posted by Johngagemn View Post
    Best thing you can do is get rid of that dang front suction! If you are looking for a connection in-line with the apparatus go to a rear suction instead. A front suction generally has to be plumbed into a downward facing ANSI flange on one of the pump's intake fittings behind the operator's panel. The sheer number of elbows and bends required to make it fit in, on, and under the apparatus make it a horrible way to bring water in.

    A rear intake generally runs a straight shot along the frame rail and then directly into the back of the same fitting. It's a longer run of pipe, but with almost no bends in the pipe the friction loss is minimal even at high flows.


    With regard to your initial question about changing hose, the question really comes down to which one of those suction lines that you were carrying got connected as a general rule. If it was the 5" on the front, then you took a step backward, if it was the 3" on the side, you took a huge leap forward.

    As for replacing the 3" in your hose bed with 4", you absolutely took a step forward there. Would 5" have been better? Sure. But you could also argue then that everyone should just get it over with and buy 6".

    My department ran 4" for all of our main supply and relay hose. Guess what we found? You know those 2.5" side ports on the hydrants? We would get maybe another 350 or so GPM out of those when we ran 2.5" hose from there to an intake. When we used an adapter and ran 4" from that same 2.5" hydrant nozzle we could get flows near 1000 GPM. Granted this is all dependent on the residual hydrant pressure, but you get the idea.

    Another thing we discovered: when you need to hook into an FDC you get better flow by running a single 4" than you could by running two 2.5" (I know you have been using 3", but again, you get the idea here). When you're pumping to the ladder pipe on your stick you can do the same thing, or if you really need big water run dual 4" lines. I'm not saying there's anything wrong with the way you guys were doing it previously, just trying to point out that sometimes a little bit of outside-the-box thinking can create a huge benefit.

    If there is one big advantage to standardizing on all 4" as opposed to keeping that 5" on the front it is that you will only need one kind of adapter for your LDH instead of having to carry adapters for both 4" and 5". At some point somebody would screw that up and delay getting water to the engine, and now you're stuck with an empty tank while somebody scratches their head over why the hose won't connect and then has to go get a different adapter.
    I can get up to 1800 GPM from my front suction off a hydrant (thats just messing around, never really "tested it". Did 1100 with 12' of suction hose drafting too. Its got a swivel connection and 25' of 5" hose. Our rig has a 1250 Hale Qflo. Its fast and easy to hook up and affords me the ability to make a hookup (if I am close enough to use it) much faster than pulling out donut rolls and hooking up pieces to parts etc. With 2 1/2" x 4" storz gate valves, I can get more water into my main pump inlet if I need it. In my front bumoer suction hose well, the 25' section is preconnected to the swivel and no adapters are required for connection to the hydrant. The hose is packed in a horseshoe and unside the center is the gate valve with storx adapter already attached. nect to the well is a set of wrenches and a mallet mounted on the bumper. one stop shop. If I'm not in a position to use the front suction, I most likely have laid out from a hydrant and in that case I have a 25' and a 50' section of 4" in my hose well along the side and the main intake already has the appropriate adapter on it.

    Obviously, if I know I am looking for maximum water, I'll use my main pump intake(s) but the front intake offers speed and versatility for initial water.

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    Cool Determining Size of Supply Line

    Originally posted by MG3610

    You have some good insight. Stick around here and be a regular contributor.

    Did you try two 4" lines off a hydrant at all and figure out flow capabilities?
    I think this is the right direction to go..... You must have figured-out your max. flow(s) and based your size of your Supply Line based on the capabilities of your Water System, that's why you made the change. If your Water System can't supply 5" Hose then why carry it? Good solid thinking.....

    DISCHARGE RATES BY OUTLET SIZE

    Outlet Size: Flow Rate:

    2 ˝” 250 gpm

    3” 375 gpm

    3 ˝” 500 gpm

    4” 625 gpm

    4 ˝” 750 gpm

    5” 1,000 gpm

    I realize that more water can be pumped through a Pump than these, but it's always been a good General Rule.....

    We carry 5" Supply Hose with Storz and we've been trying to convince our Chiefs to go with 4" with a small adapter instead of "The Football" that we currently have in all of our L.D.H. Hose Beds. Our hydrants have 4" and 4 1/2" discharges so it makes since to us to switch. Plus, the weight and cost difference is a bonus.
    "Be LOUD, Be PROUD..... It just might save your can someday when goin' through an intersection!!!!!"

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    Quote Originally Posted by mikeyboy View Post
    Originally posted by MG3610



    I think this is the right direction to go..... You must have figured-out your max. flow(s) and based your size of your Supply Line based on the capabilities of your Water System, that's why you made the change. If your Water System can't supply 5" Hose then why carry it? Good solid thinking.....

    DISCHARGE RATES BY OUTLET SIZE

    Outlet Size: Flow Rate:

    2 ˝” 250 gpm

    3” 375 gpm

    3 ˝” 500 gpm

    4” 625 gpm

    4 ˝” 750 gpm

    5” 1,000 gpm

    I realize that more water can be pumped through a Pump than these, but it's always been a good General Rule.....

    We carry 5" Supply Hose with Storz and we've been trying to convince our Chiefs to go with 4" with a small adapter instead of "The Football" that we currently have in all of our L.D.H. Hose Beds. Our hydrants have 4" and 4 1/2" discharges so it makes since to us to switch. Plus, the weight and cost difference is a bonus.
    The part you may be overlooking is that if your water system is weak, 5" hose will deliver the same flow of 4" hose quite a bit farther (less friction loss). In essence, it almost makes more sense for the poor water system to use 5" and the better system to use 4"

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    Quote Originally Posted by MG3610 View Post
    The part you may be overlooking is that if your water system is weak, 5" hose will deliver the same flow of 4" hose quite a bit farther (less friction loss). In essence, it almost makes more sense for the poor water system to use 5" and the better system to use 4"
    Mike, your point on using 5" on a weaker system is right on. It's one of the best uses for LDH. The only down side is the length of time it would take to get the first water to the attack engine. At one gallon per foot, with a 2000' lay (not unheard of) and 500 gpm flow, you've got four minutes just to get the water there. But even though it's not best practice, it's easily doable without a relay engine. That being said, I'm a proponent of using 5" on pretty much any system.

    In the days of laying a single line 2-1/2 as your water supply we'd burn a building down and complain to the newspaper reporters of low water pressure. The reality is, the water was there, we just weren't doing what was needed to get it from where it was to where it was needed, nor did we have the stuff to do it with.

    For an example of 5" on a large water system, go into East Coast 911. Root through their commercial section and look for Lower Moreland, Pa. 2/12/2007. On the second page there is a series of photos of our Quality/Duplex. You'll see one 5" line coming in, but what you don't see is the second 5" line coming in on the other side (parallel laid in on arrival). I'm supplying a Squrt, two ladder pipes and a ground monitor. You might even see me in a couple of the shots. Still had plenty of water at the guzintas, but ran out of guzoutas to put it through.

    Of course, you'll also see what transpired about three or four hours into the job. And you can expect some comment from FWDbuff as soon as he sees this.
    Last edited by chiefengineer11; 11-08-2009 at 04:34 PM.

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    Quote Originally Posted by chiefengineer11 View Post
    Of course, you'll also see what transpired about three or four hours into the job. And you can expect some comment from FWDbuff as soon as he sees this.
    Next time, let it burn a few minutes longer so that we have to replace that godforsaken piece of crap, or at the very least, repaint it red!
    Last edited by FWDbuff; 11-08-2009 at 03:47 PM.
    "Loyalty Above all Else. Except Honor."

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    Thanks again for all your replys.

    You guys sound like your pretty used to higher pressure, higher flow hydrants than we are. A fifty or sixty pound static hydrant is common place and in some areas of the city and it will immeadiatly fall on it's face until you look up and you're under 5psi.That's why I'm so against using a single 4" for a front suction hose, as your losing too much between the hydrant and the engine.

    Before the new system was in place, we had a 25' section of 3" preconnected suction hose on the RH and LH side of the engine, in the running board hose wells. We would use a single 3" to supply the pumping engine on the run of the mill house fire and possibly two if the second engine in, saw that we had a fire. If the second engineer was thinking, he would hook his pumper to the hydrant. If not, he just connected straight to the hydrant which would leave us open to supply problems and it would make my blood boil. More than once I have seen drivers scratch their heads why we didn't have the water we needed, when they knowingly lead out with a 400' single length of 3", and didn't connect their pump to the hydrant, to make it a relay operation! I would say didn't you pay attention in FAE class? The 5" front suction would (should) be used, with a hydrant gate, if the engine lead out, or if the first engine was lucky to be positioned correctly, at the fire. Remember we engine guys have to leave room for the truck company! Once again, only if the driver was thinking water supply, was this done correctly. Another on going problem is, most of us will shrug our shoulders and make whatever is given to us, work. I will continue to push to get the 25' section of 5" back with on, with the old fashoned NST threads and all.

    In one of the replies it stated that all of their tools were carried the extended front bumper. What a concept! We sometimes almost have to run a circle around the engine to gather all the tools needed. We carry a hydrant bag on one side of the engine, in which the adapters are carried. The hydrant bag is a good idea if we do a forward lay, however we need some of the same equipment on the front bumper also. Right now only a hydrant wrench is carried in the front well. My next test will be to compare how long it takes to hook up with the old and the new set up.

    To answer another question, I tried with the last batch of new engines to do away with the front suction, to no avail. My time is short now anyway and I doubt we will be buying any new rigs, before I am out. I seriously doubt we will do an FDNY thing either, even though it is the ultimate set up. A rear suction wouldn't work, because no body would want to give up any compartment space. I've seen a rear suction on a couple of rural rigs, but not for a very long time on any of the city rigs in the area. Back in the 1970's, I remember Chicago having a few. I like to use the front suction for a "port-a-tank" operation, to keep the layout "in line" and I have drafted out of the river with the front suction, to augment a water supply issue, on a mutual aid call.

    Since 99% of our stand pipes are 2-1/2" threads we use two very short lenghts of 3" to a divider and then feed that with the 4". One engine stays near the stand pipe and with our new high rise SOP we lead out with the second engine, to make it a relay operation.

    Another question, yes I tried using dual 4" lines coming in and there was a marked improvement. All I really took time to do is mark the increased residual pressure, as I lost the accuracy of my front suction flow meter when we added the second one to the side intake. I didn't take time to figure out how much it helped us. I was just taken back by the extra time it took to put all the adapters on the hydrant.

    Back in the 1970's when we had our first front suction provided on our ALF, it had only a 4-1/2" pipe, which ran through the wheel well, so you had to have ice water in your veins if you didn't hook up the hydrant gate. All of our rigs now have 5" pipe but with all the wigs and wags in the piping, it isn't all that efficient as stated before.
    Last edited by SEMPERFI3; 11-09-2009 at 10:16 AM. Reason: a couple paragraphs were cut off from the length

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    I'm still calling this new set up one step forward and one step back.

    To add to what FWD buff wrote , when I came on we had some real junkers with rust holes thru and thru, to the point you would get all wet riding in the jump seats! I never thought I would see the day when our oldest front line rig is only six years old and all are painted red!


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    Here is ours. We also have a 25' section of 4" in the center well, seen in use in the photo below. The gate valve has the storz adapter already hooked to it. so you can make both hydrant connections without having to retrieve anything from any other compartments; everything needed is on the bumper and the LDH wrenches are mounted on the officers side panel to assist locking the connections if necessary. The photo shows a configuration that gave us 2040 GPM from that hydrant (our pump is a medium sized 1250 GPM single stage).



    The below photo shows that we have our steamer inlet reduced from 5 to 4" and have a 4" adapter on our 3" aux suction inlet. It gives us quite a few options.


    Semperfi, If you get stonewalled by admin, are you guys allowed to add your own accessories to the rigs. You can usually find cheap adapters wrenches etc and such on Ebay and sometimes you gotta spend a little coin out of pocket when you care and know theres a better way to do something (as long as you cant get jambed up for it).
    Last edited by MG3610; 11-09-2009 at 12:34 PM.

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    Quote Originally Posted by MG3610 View Post
    I can get up to 1800 GPM from my front suction off a hydrant (thats just messing around, never really "tested it". Did 1100 with 12' of suction hose drafting too. Its got a swivel connection and 25' of 5" hose. Our rig has a 1250 Hale Qflo. Its fast and easy to hook up and affords me the ability to make a hookup (if I am close enough to use it) much faster than pulling out donut rolls and hooking up pieces to parts etc. With 2 1/2" x 4" storz gate valves, I can get more water into my main pump inlet if I need it. In my front bumoer suction hose well, the 25' section is preconnected to the swivel and no adapters are required for connection to the hydrant. The hose is packed in a horseshoe and unside the center is the gate valve with storx adapter already attached. nect to the well is a set of wrenches and a mallet mounted on the bumper. one stop shop. If I'm not in a position to use the front suction, I most likely have laid out from a hydrant and in that case I have a 25' and a 50' section of 4" in my hose well along the side and the main intake already has the appropriate adapter on it.

    Obviously, if I know I am looking for maximum water, I'll use my main pump intake(s) but the front intake offers speed and versatility for initial water.
    If those numbers are correct then you are extremely lucky, and/or the plumbing had to have been run in such a way that you have severely sacrificed ground clearance by running it in a straight shot under the axle.

    Here is a link to an excellent article by Larry Davis about front suctions:
    http://www.gotbigwater.com/content/a...rticles_05.pdf

    It was published in Fire Engineering a few years back and I've always found it to be an excellent reference for people to read to truly understand how horrible front suctions are for pump performance. While Larry's primary focus was on rural water supply, as he notes in the article the same principles also affect operation from hydrant. I wish he was still around to keep educating people about water supply as he was truly a genius in that field.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    MG3610 I really like the handkerchief type hose wells especially for the front suction. It's a very good use of available space. The tools go without saying. The only down side is protection from the elements. What a concept 5" suction hose with NST threads! It looks like you can rip the hose out of there and just as importantly re-load it all pretty easily. As far as getting our own fittings I am afraid all the rigs must be alike (although some are not) so there won't be any chance on getting our own. Gotta fight this head on.

    And Johnny gage (pardon my nick name) even with all the down sides to front suctions and even if all the evils be known to all people, they are just too popular. A front suction is like a blond bomb shell of sorts. Your kicking a dead horse. The rear suction pictured is a pretty cool set up, beacuse you slide the hard suction off and hook it right up to the port-a-tank.


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