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I work in a small Federal Government departmant in Eastern Oregon.
I was talking to one of our new Capt.about changing from 3inch to 5 inch hose. He told me that the chief would not change to 5 inch because it is to heavy and our hydrents have to low pressure.
what can I do to change there minds?
Around here, wagons that don't lay in aren't likely to get water...a line is dropped for every report of fire or smoke in a building, even if it is only a 3" line. The only exceptions are when: A) there's a hydrant for the pumper to hit right in front of the fire building (usually where the truck needs to be!) B) When a truck, squad, or a chief arrives first and reports for units to stand by. Typically when we go for auto alarm, etc. One engine will standby for the reverse lay while we investigate. I've never seen a buiding burn down for lack of water (in a hydranted area), and all we have for the most part is 3".
5 Inch, 5 Inch, 5 Inch, 5 Inch, 5 Inch!!!!
Can I be any more forceful?!
1200' in 100' sections should suffice in most situations. If you have the ability, cary more on the 2nd due piece.
Dont forget to make 1 25' and 1 50' "curb jumpers" for when the hydrant is located infront of the structure, or if an engine is needed to fill tankers from a distant hydrant.
Stay Safe and Stay Low
Brian
Just would like to get some input on the following.
When using 5 Inch LDH, do you connect to your pumper's steamer or do you reduce it and go into a smaller intake. If you have operated both ways in the past, what were your results? what kind of flow rates did you oberserve?
Nice to see someone who can use the search function!
We use piston valves on our steamer connections with a pressure relief valve. The relief valve is important to get the air out of the line when you charge it, you would be surprised how much air it holds. Not something you want going through your pump. The relief valve also is a good indication when you have some lever puller on the pumper sitting on the plug that is being over zealous with the throttle on your supply line. I believe most LDH is rated at 200 psi so you don't want to go crazy with the pressure on them.
The piston valves are a bit of a hassle to take off when you draft, however. There may be valves available that do both, allow hook up to a supply line or to hard suction for drafting.
If you really want to move "big water" hook two fives on your hydrant and feed both sides of your pump. You would be amazed on how much water you can get out of plug. Believe me, you will safely exceed the tested gpm of any hydrant. You are not "making water" or gaining pressure, you're just make the hole that the water flows through bigger.
Yeah, I'd agree with the whole don't go crazy with putting too much pressure on 5". It tends to hurt people "very much badly" when it starts jumping around.
You'll have much less friction loss with the 5" hoseline. I'm quite sure the main supplying the hydrant is not 3", so taking a 5" hose off the hydrant won't give you pressure problems. Always go with the 5" if you can....You can never have too much water. I wouldn't say carry one or the other though. We carry both in the bed. 500' of 5" and 750' of 3".Quote:
Originally Posted by Tom65
We too use 4" PRV's for our LDH, and they flow beautifully.
We have the adapters to use the 2.5 intakes and discharges if desired, and they work well in training to supply our monitors at full pump capacity (1050 imperial pumps). We have not flow tested anything though to see if there is a measurable difference in the two supplies.
Unless you are supplying a large pump over 1500 gpm, I would not expect to notice a large difference between 5 inch into a steamer vs 5 inch into a 3" intake. A short 3" intake is still capable of receiving 2000+ gpms of water with adequate pressure.
We have been using a butterfly valve on the intake side of the pump. In the past we were directed to take the butterfly valve off during drafting operations. This is a time consuming process that requires a rubber mallet and lots of foul language.
Anyway all of our new engines are able to pull a draft through the butterfly valve, give it a try.
Standard supply LDH is 180psi operating, annual test to 200psi.
There is "Attack" LDH that operates at higher pressure for feeding standpipes, possibly master streams in industrial situations.
Normally through the PIV on the steamer when water supply is from a constant source -- hydrant or drafting. To the tank fill when it's a leader line from a tanker dump site.
We use the TFT Ball intake valves on our engines. You do not have to remove them to draft. We have used the piston intake valves in the Past. We recently purchased two TFT Jumbo intake valves. The TFT valves are finished off with 6" hose thread on the pump operator's side and finished off with 5" storz on the other side. Our normal operations call for the 5" supply line to be connected on the side away from the pump operator. If drafting we use the pump operators side. We also carry adapters to hook suction to the storz side and 5" to the drafting side.
The TFT BIV will allow a draft of about 700 gpm to 800 gpm.
The TFT Jumbo intake is supposed to allow over 1000gpm at draft, but we have not had a chance to test it.
We are split, about half the time we are able to use hydrants, the other half we use tanker shuttles.
The 5" hose makes the pump operators job alot easier for us. It allows for the full flow for almost all of our hydrants up to 1000' away. The 5" hose to me is not much worse to load than the canvas 2 1/2" we used to carry.
All you have to do is ask HER!
Same concurrance here in regard to LDH. WE have utilized 5" for nearly 15 years now and it solved much of our supply problems experienced when using dual 2 1/2 or 3" lines. With the LDH you are basically taking the water main and laying it on top of the street. The one thing I can say however in regard to it not being fully charged with water is that you can run the risk of collapsing the hose and you must get all the air out as well. This is true with any supply hose, which is why I am not a fan of putting the LDH intake on the passenger side. I always keep my leg against the hose as I am charging lines and watching my residual, it has been my experience that I can feel the hose softening if a supply issue occurs...long before I will see it on the gauge or hear it in the RPM's.
Tom 65...I feel for you. Some of those arguments as to why your Chief doesn't want to switch are invalid and IMO utterly ridiculous. It takes 6
2 1/2" lines to equal a 5" line. Too heavy? Since when is that an argument for not getting something that works better? Are the irons too heavy? Is it better to lay 2 lines and pack that much hose then just the 1 LDH? Contact Angus and see if they can give you a copy of their Hi-Vol video. It has some good info in there. Thousands of departments can't be wrong. Sexless couplings eliminate the need for many adapters and so forth.
Time to hear from the Party Pooper....... We do not use anything larger than 3 inch for supply line, and have no interest in changing. Here's the scoop:
Water Supply...... We have a largely outstanding water system, with only a few problem areas, which are being addressed.
Apparatus....... About 6 or 7 of the approximately 90 Engines in the County carry LDH. One Station ( www.clintonvfd.org ) operates several Engines with 2,000+ GPM Pumps and large loads of 5 inch hose. they respond as the Water Supply Company on all 2nd Alarms County Wide.
Operations...... Our SOPs are pretty tight on water supply, here's an example: Box Alarms get 4 Engines, 2 Trucks, (Ladders) and a Squad (Heavy Rescue) The first Engine drops a Supply line at the Hydrant nearest the Fire on his way in. (Dual lines for Heavy Smoke/Fire visable) 2nd Engine picks up the Hydrant and pumps the line to the First Engine. 3rd Engine drops a line at a different Hydrant, stretches in to the Building, 4th Engine picks up the 3rd Engine's line. We ALWAYS put an Engine on the Hydrant. ALWAYS.
It sounds like you are set for your situation. You also have the luxury of the number of pieces available to you and one company set up as your water supply for big jobs county wide.Quote:
Originally Posted by hwoods
Most places are not as fortunate as you are with redundant 2 and 1 responses (2 engines and a ladder X 2).
When I took over as Chief we did not have LDH. We needed it and now have used it for about 8 years now. Even the people who did not want it did not complain that they had a 5" line supplying them at the working fires they were running the attack engine at.
Chief,Quote:
Originally Posted by hwoods
Even so, you could still flow more water at lower pump discharge pressures if you made the change to 5" and used your same SOP.
Quote:
Originally Posted by MemphisE34a
Bob's right, of course, and there is no one single reason that most of us don't like the stuff. For instance, I bounce over charged 3 inch line on a regular basis, but NOBODY drives over charged 5 inch. (I did see a Camaro try it once, the line burst and threw the car about 10 - 12 feet, almost turned it over) and the usual complaints about the weight when repacking it. And, our "Bread and butter" Fires don't require that kind of Fire flow. As I noted above, we have a system, and it works well for us. :)
I have read with interest some of these comments concerning the use of LDH. There are several entries asking for help with practices that enhance the movement of large volumes of water. TRAINING6604 asked about reducing the LDH to 2 1/2 “, and putting the water into the gated intakes (Pony Suction). This is definitely not the way to connect LDH. Generally, 2 ½ “ pipe is designed for flows up to 250 gpm, at this flow an elbow has about 1.5 psi loss but the losses increase by the square of the flow. (Hazen – Williams formula) Putting 500 gpm through the elbow will cause a drop of about 6 psi per elbow and 1000 gpm will cause 24 lbs loss. Combine this with the fact that most pony suctions have at least three (3) – 90 degree bends you will rapidly negate any advantage that you gained by laying 5” in the street. It is best to attach a 6” X Storz directly to the steamer connection. A combination gate and relay relief valve set at 150 to 180 psi will ensure that the attack engine is able to continue to supply attack lines without interruption while switching over from tank water to the LDH supply. You will need to set the operating point of the relief valve above the highest hydrant pressure that you normally encounter in your system. We have some hydrants in our system that approach 200 psi static, but with increasing fire flow, rapidly drop below our SOP set pressure for relief valves at 180 psi.
Repeated radio chatter by pump operators can be reduced to nearly none by the following actions.
1. Initial attack lines on residential fires (2- 1 ¾ + 2 ½) - Connect the relay engine to the hydrant, but do not place the pump in gear. Allow the hydrant to push right through the engine. Hydrants in the range of 50 to 60 psi at 600 gpm will deliver adequate volume to the attack engine at a distance of 700 feet or more. (Fl=K*Q*Q*L) Fl=1/15 * 6 * 6 * 7 or Fl = 16.8 psi Losses in the relay pump would be about 20 psi so at 600 gpm the attack engine would see at least 14 psi on the intake (compound) gauge. Why place the relay engine in the loop? Just in case there is a sudden increase in the required water. Be aware that the pump will be rotating due to the water flow, and it might be necessary to temporarily stop water flow (attack pumper switches to tank supply for 10 seconds or so) while the engineer shifts into pump gear.
CAUTION! If you place the relay engine in gear, you can expect to generate about 60 to 80 psi above incoming hydrant pressure. Thus discharge pressure would be 140 psi and incoming at the attack engine would be 125 psi. Now the attack engine at idle will be developing 200+ psi making it difficult for the attack crews to control nozzles and hose lines and defeating any pressure governor control or relief valves.
2. Multiple apartment or small commercial structure (10,000 sq ft.) calls for about 1000 gpm (3 – 1 ¾ + 2 – 2 ½) or some similar combination . Place the relay engine in gear, but keep the rpm just slightly above idle and not more than 100 psi discharge pressure. As long as the attack engine has an incoming pressure below 80 psi, the relief valve or pressure governor should be able to control pressure fluctuations.
3. In the event that master streams will be supplied (2 – master streams with 1 ¾” tips) 1600 gpm can be delivered by the relay engine at 150 psi and still have about 40 psi incoming at the attack pumper.
4. Maximizing the relay engine at 180 psi should result in the delivery of nearly 2000 gpm through the 700 feet of 5” hose. If you are running the attack engine, you can carefully take the intake pressure right down to zero without risking failure of the relay. Contrary to some thinking, you can ‘t “suck the intake shut” , but might cause cavitation if you turn the rpm up too high. The intake hose will begin to collapse, but the reduced cross section will cause an increase in friction until the internal pressure in the hose exactly matches the air pressure on the outside of the hose. (turbulence losses in the intake) This high velocity and violent shaking can tear the inner liner out of old or poorly bonded hose, so be careful.
5. Summarizing steps 50 psi = Level 1, 100 psi = level 2, 150psi = level 3 & max (180) psi should cover all the needed discharge pressures for the relay engine. Radio chatter = “Engine 12 boost your output to level 2” (100 psi) and you are done on the radio. You don’t need to bump 10 lbs at a time.
Have used both, the gain of 5 inch is obviously more water than 3 inch. I have only really seen one substantial argument for 3 inch over 5 inch, that is you can pack more 3" on the truck than 5" which I suppose is true. Where I am atleast it is a mute point. We have a freakin working hydrant almost every block so 1000' of 5" generally does the job for us on our engines. Besides Im a truckie.....we dont need no stinkin' hoses! Stay safe all.
The only problem I have with 5'' is that you must have a good water supply, It takes a lot of water to fill 500' of 5'', but I am a fan of it, there is no reason to use smaller when you have bigger!!