Trash pump, vs High pressure fire pump?

[BeatCJ]

Ya better hang on to that hose for now... might need it this year, though I wouldn't turn it down, I could probably get a lot more then 2 seasons out of an old hose... (get yer mind out of the gutter)

Nope, we won't. We don't use that thread at all. We use almost all standard fire service thread, or the quarter turn sexless couplings DNR uses (take that one to the gutter). I don't really like the quarter turn stuff, the couplings are big knobby things that can get hung up easier on stuff when you are dragging it. It is a lot easier for barely trained kids to figure out, since you don't need to know male threads from female, or 1 1/2" from 1".

Fire service in general uses a much coarser thread, and the end of the thread has what they call a Higbee cut. It's a lot harder to get it cross threaded.

This is stuff that was getting cleared out of a warehouse to be thrown away. Had a red stakebed show up at my office, the boss says to check with you before we haul it to the dump. They don't use threaded hose, the green truck people don't want it back. I gave away a lot of it to other local fire agencies, used it some, but the larger stuff with our threads that we have had on trucks is starting to fail. It's has been stored inside, so it's probably good for a little while.

 

[2dogs]

Nope, we won't. We don't use that thread at all. We use almost all standard fire service thread, or the quarter turn sexless couplings DNR uses (take that one to the gutter). I don't really like the quarter turn stuff, the couplings are big knobby things that can get hung up easier on stuff when you are dragging it. It is a lot easier for barely trained kids to figure out, since you don't need to know male threads from female, or 1 1/2" from 1".

Fire service in general uses a much coarser thread, and the end of the thread has what they call a Higbee cut. It's a lot harder to get it cross threaded.

This is stuff that was getting cleared out of a warehouse to be thrown away. Had a red stakebed show up at my office, the boss says to check with you before we haul it to the dump. They don't use threaded hose, the green truck people don't want it back. I gave away a lot of it to other local fire agencies, used it some, but the larger stuff with our threads that we have had on trucks is starting to fail. It's has been stored inside, so it's probably good for a little while.

Grrr! I hate the red truck vs. green truck friction. Cal Fire (red trucks) wants to go direct on every fire. They have lots more burn injuries as a result. They claim they want to keep the fire to minimum size. Plus they carry so much stuff on their type 3s that water tanks and frames are cracking. The USFS (green trucks) don't like to work in the smoke, they have that damn JHA to calculate, and they have more paperwork than congress.

 

[BeatCJ]

I don't see much of that here, but I rarely work federal fires. I deal with WA DNR all the time, so we have a great relationship. They have jurisdiction on most fires on unimproved property outside of federal ground, so a lot of our fires, we are dispatched by 9-1-1, we call them and they take over when they get there. I try to keep it that way, so when Mrs. Smith is having a heart attack, our staff is available to help her. We can deal with mop up if we need to, but it seems like the best use of resources

 

[northmanlogging]

Nope, we won't. We don't use that thread at all. We use almost all standard fire service thread, or the quarter turn sexless couplings DNR uses (take that one to the gutter). I don't really like the quarter turn stuff, the couplings are big knobby things that can get hung up easier on stuff when you are dragging it. It is a lot easier for barely trained kids to figure out, since you don't need to know male threads from female, or 1 1/2" from 1".

Fire service in general uses a much coarser thread, and the end of the thread has what they call a Higbee cut. It's a lot harder to get it cross threaded.

This is stuff that was getting cleared out of a warehouse to be thrown away. Had a red stakebed show up at my office, the boss says to check with you before we haul it to the dump. They don't use threaded hose, the green truck people don't want it back. I gave away a lot of it to other local fire agencies, used it some, but the larger stuff with our threads that we have had on trucks is starting to fail. It's has been stored inside, so it's probably good for a little while.

Well if'n yer just going to chuck it then by all means send it this way, Think I have enough in paypal to cover shipping I'll pm ya with an address.

 

[BeatCJ]

I will try to get it sent Wednesday. I have to get through my honey-do list before my crews get back from their two weeks at the Kettle Complex. We got back from two weeks out, fueled and knocked out the air cleaners, fixed a loose wire in the tail lights and fresh warm bodies went out. I suspect it will be the same turn around, so mama has a list.

 

[northmanlogging]

I'm considering getting into the black myself next year maybe, have to follow through on some classes and gather some equipment, special pants, special shirts, expensive hats, etc... We'll see day job pretty much said I'd be fired if i wen't whole hog with it... What they don't know is that I figure it will make up for the slow times in logging... and I won't need a day job no more... until then.

 

[2dogs]

If he is dragging 200', it's most likely not 1 1/2", more likely 1". So friction loss will be significantly more, at 30 gpm, 23psi per 100'.

I know, he's a bull

Do your saw shop guys have access to the pump curve? Most times, as flow decreases, pressure rises. So at 50 psi, that pump is flowing 250 gpm (all numbers pulled from my posterior, generalized, not necessarily accurate). But, at fire flow, 40 - 50 gpm in your case, the pump may be capable of 150 psi. For you, that would give you about 75 psi at the nozzle. Not quite desirable, but it would work. Most fire nozzles are designed to give optimum pattern at 100 psi nozzle pressure.

I have been sitting on my hands over this post because CJ is a good guy and his first post was right on the money. But here goes. First off he is a bear not a bull. Small matter but let's set the record straight.

Second off, decreasing the diameter of the discharge hose does not increase the nozzle pressure, it decreases it. Again lets talk about water flowing in a hose on level ground, that is no elevation change. Also lets say we are drafting out of Northbear's new water buffalo. (Let's ignore CJ's example of 50 psi and 250 gpm as that would mean a BIG pump, somewhere between 4" and 6" diameter discharge). Let's use a Honda WX20 which is a 2" "high pressure" pump. It pumps roughly 100 gpm at 30 psi and 50 gpm at 50 psi I am guessing it costs around $1,500.00. In addition it will pump a maximum of 61 psi. This means if you have a shutoff nozzle on the end of the hose and you read a pressure gauge at the pump discharge, as you shut the nozzle down it will reach a maximum of 61 psi when the nozzle closes. It does not matter what the diameter of the discharge hose is when no water is flowing. It could be a 3" line.

But let us look at the example of 50 psi and 50 gpm. This pump would have the 2" discharge reduced to use 1 1/2" hose and a 1 1/2" fog nozzle rated at 50 gpm at 50 psi to match the pump's output. As water flows through a hose the internal friction of the water against the hose lining cause a pressure drop called friction loss. All hoses create friction loss. The friction loss we be approximately 10 psi per 100'. Even with only 100' of hose the nozzle can now only flow 40 psi. That is all the water it can get. A drop in nozzle pressure also means a drop in gpm. Now the nozzle is flowing maybe 40 gpm at 40 psi. Reducing the diameter of this hose from 1 1/2" to 1 " means a drastic reduction water flow. Trying to get 60 gpm out of 1" hose would mean something like friction loss of 40 psi per 100' of hose. With a fire engine you could crank the throttle up and force the pressure much higher and make up for that loss. In other words you apply much more energy to the water flowing in the hose. With a fixed RPM 160cc powered pump you can not make that happen.

A centrifugal pump impellor spins in the housing and throws water from its center outward into a curved pump housing called a volute. The spinning impellor touches nothing but water (or air when there is no water) and can only transfer a fixed amount of energy to the water. This energy is interpreted as water pressure. CJ's example of "fire flow" would mean there is more pressure at the nozzle than at the pump. This would mean the water would have to flow backwards until the pressures were equal.

The nozzle pressure will always be equal or more often less than pump pressure. OK there is a way to make the nozzle have a higher pressure than the pump and you guys know what that is. Just let gravity work for you at 1/2 psi per foot. Run the hose down hill till you are 500' below the pump and you will add 250 psi at the nozzle.

Long hose lays uphill require the opposite approach. You will need lots of pumps and relay tanks. Of course as the elevation changes the pumps don't work as well. Anyone know why?

 

[Marshy]

Yeah, power is cubed.

 

[Gologit]

'Cause the dozers keep running over your hose lays?

 

[2dogs]

'Cause the dozers keep running over your hose lays?

Every dozer I ever worked with on a fire was as careful as possible. They would push up a mound of soil as pile it on the hose lay and drive over it. Of course I never worked with you.

 

[northmanlogging]

northybear... mehhuh...huh, huh..

 

[Eccentric]

At higher elevations there is less oxygen in the air. Less oxygen in the air means less power from the pumps engine.

 

[2dogs]

At higher elevations there is less oxygen in the air. Less oxygen in the air means less power from the pumps engine.

Close but no cigar. Hi Aaron

 

[Marshy]

At higher elevations there is less oxygen in the air. Less oxygen in the air means less power from the pumps engine.

And the relationship between flow and HP is to the 3rd power. So a 10% reduction in HP will reduce flow by about 4%. However, a 10% reduction in HP will cause a about a 7% reduction in pressure. Pump affinity laws, good stuff. Change in flow is proportional to change in pressure squared. Change in flow is proportional to change in HP cubed.

 

[2dogs]

And the relationship between flow and HP is to the 3rd power. So a 10% reduction in HP will reduce flow by about 4%. However, a 10% reduction in HP will cause a about a 7% reduction in pressure. Pump affinity laws, good stuff. Change in flow is proportional to change in pressure squared. Change in flow is proportional to change in HP cubed.

Sorry.

 

[Marshy]

Not necessary to be sorry. Those are the pump laws, they don't care.

HP Loss = (elevation x 0.03 x horsepower @ sea level)/1000

 

[2dogs]

No I mean sorry you didn't win the grand prize. Keep working!

 

[Marshy]

Your questions could be clearer IMO. Maybe I didn't read it right?

By changing the resistance of the system you move back on the curve. With centrifugal pumps you can reach shutoff (dead head) from adding more hose or adding elevation at the discharge. The higher you go up with the discharge the less flow and pressure you will get.

 

[BeatCJ]

I have been sitting on my hands over this post because CJ is a good guy and his first post was right on the money. But here goes. First off he is a bear not a bull. Small matter but let's set the record straight.

I accept the correction. Thank You. My thought was that I had never seen a bear hitched to a load, but I have seen logging done with oxen.

Long hose lays uphill require the opposite approach. You will need lots of pumps and relay tanks. Of course as the elevation changes the pumps don't work as well. Anyone know why?

Something like Starlings Law? Cardiac Preload?
A couple of weeks ago we pumped a 2800' trunk with one BB-4. Only used a few nozzles at a time, but it worked fine.

And FWIW, I have never had a dozer run over one of my lines. Several times we have had engines run over them and drive crushed rock through them, though.

 

[Gologit]

Every dozer I ever worked with on a fire was as careful as possible. They would push up a mound of soil as pile it on the hose lay and drive over it. Of course I never worked with you.

I've never run over an active hose lay. Sometimes though, if things get a little confused and a crew moves on and somebody else is supposed to come along and roll hoses and they don't show up and it's night time and we're just plain damn tired of building speed bumps over the hoses and we remember the last time we had to listen to somebody snivel because the speed bumps were too high and it took them too long to dig their hoses out 0r it's several days past cutting line and we're into remediation and the damned hoses are still out there and everybody you've mentioned it to has ignored the information...well, you know. Things happen.