Maximizing Hydrant Connections - Water Flow Test Results

[txgp17]

I’m sure most of you have heard the term “maximizing a hydrant” which involves attaching lines to every port of a hydrant to get every ounce of available water into your pump. But exactly how much more does that give us than a 4½" port alone? I’d always wondered how much more, so I decided to perform a test using a flow test kit. Keep in mind that these results will not reflect the performance of all hydrants, but it is good info just the same.

The hydrant used was a private hydrant in the parking lot of vacant commercial property; its static pressure was 65 psi and it's on an 8" water main.

The pump used was a Hale QMax rated at 1,000 GPM with a 2.1 ratio, and it was driven by a Detroit 60 series.

First, we stretched 100’ of 4” hose off our 4” discharge and connected it to a ground monitor. Then we attached a 2½” smooth bore pitot tip used for service testing. We then made the following hydrant connections:
A. 4½” steamer to Piston Intake using 50’ of 4” hose
B. 2½” port to auxiliary intake using to 50’ of 2½” hose
C. 2½” port to 4” Storz adapter to front intake using to 50’ of 4” hose

Then we tested how many GPM we could get from each combination of intake arrangements, opening each as needed, and drawing the residual intake pressure to 10 psi each time.

A - 1,306 GPM
A & B - 1,481 GPM - 13% more than 4½" port alone
A & C - 1,751 GPM - 34% more than 4½" port alone
A, B, & C - 1,784 GPM - 37% more than 4½" port alone

The big point here is that using LDH hose on the 2½” port, feeding a large intake yielded more than twice the amount of additional water than using a 2½” hose to a small intake. I think this is evidence that we need two large valved intakes on every Engine/Quint to receive large volumes of water, and two LDH discharges to move this water to another location. And I do mean true LDH discharges, not 2½'s with LDH adapters screwed on.

[VanIsleEVT]

I'd be curious to see what the GPM would be with a single 5" from the steamer to the piston intake. I'd bet it would be awfully close to the parallel lines.

You've got about 17 psi loss in that single 4" supply line. It would only be 11 psi with a single 5".

[kuh shise]

txgp17:

I used your information, made several assumptions like the number of 2 1/2" elbows inside the pump panel and the length, number of ells in the front suction, then calculated friction losses for each scenario. I added the 10 psi that you held on the intake gauge and plotted these values on a hydrant supply analysis graph. (attached) I'm curious as to how close I came to the actual static pressure of the hydrant.

VanIsleEVT:

I agree whole heartedly with your suggestion to use 5" from the hydrant. My estimate is the hydrant would supply about 1900 gpm through the single line. It would be interesting to find out if txgp17 could try 50 or 30 feet of 5" to replace the 50' of 4" from the hydrant to the piston intake.

[TFD9427]

We did a similar drill last year. We had a quint lay out about 300' of 5" LDH. It was attached to a hydrant by a humat valve. We then tried flowing the Ladderpipe to the 75' Quint, a 500 gpm blitz gun and a 2 1/2". We could not flow everything at proper pressures without it affecting each other. We then placed an engine to pump the hydrant. It increased the flow, but not by much. The a 2 1/2" gate was added to the hydrant attaching another 5" LDH line into the pumping engine. This again increased flow, but not by much. After watching this and everyone stairing at the hydrant trying to see if this would grt us more water, we added our "Crazy Hookup" It is a gated siamese with 2 3" lines into a 5" LDH. The lines were placed on both 2 1/2" ports and the LDH was placed on anothe LDH intake of the pumping engine. After that was done there was a dramatic increase in water. So much that the relief valve of the Quint was dumping water and all line open were maxed. The theroy we figured is if there is water in the ground we need to get every drpo (gpm) by utilizing every port you can with the biggest line you have. Of course that means you need to know your water supply and hydrant system. We also found that this would not work for us in some areas because the isnt enough water in the ground even for 1 5" LDH line.

[TFD9427]

I’m sure most of you have heard the term “maximizing a hydrant” which involves attaching lines to every port of a hydrant to get every ounce of available water into your pump. But exactly how much more does that give us than a 4½" port alone? I’d always wondered how much more, so I decided to perform a test using a flow test kit. Keep in mind that these result will not reflect the performance of all hydrants, but it is good info just the same.

The hydrant used was a private hydrant in the parking lot of vacant commercial property; its static pressure was 65 psi. I had no data on its flow performance before this drill, and I don’t know what size main its on.

The pump used was a Hale QMax rated at 1,000 GPM with a 2.1 ratio, and it was driven by a Detroit 60 series.

First, we stretched 100’ of 4” hose off our 4” discharge and connected it to a ground monitor. Then we attached a 2½” smooth bore pitot tip used for service testing. We then made the following hydrant connections:
A. 4½” steamer to Piston Intake using 50’ of 4” hose
B. 2½” port to auxiliary intake using to 50’ of 2½” hose
C. 2½” port to 4” Storz adapter to front intake using to 50’ of 4” hose

Then we tested how many GPM we could get from each combination of intake arrangements, opening each as needed, and drawing the residual intake pressure to 10 psi each time.

A - 1,306 GPM
A & B - 1,481 GPM - 13% more than 4½" port alone
A & C - 1,751 GPM - 34% more than 4½" port alone
A, B, & C - 1,784 GPM - 37% more than 4½" port alone

The big point here is that using LDH hose on the 2½” port, feeding a large intake yielded more than twice the amount of additional water than using a 2½” hose to a small intake. I think this is evidence that we need two large valved intakes on every Engine/Quint to receive large volumes of water, and two LDH discharges to move this water to another location. And I do mean true LDH discharges, not 2½'s with LDH adapters screwed on.

Funny you brought this up. I was just talking to someone about a month back about this same topic. He happens to have just taken and passed the Engineers position in Greensboro. I wonder if you were both at this same drill?

[txgp17]

Funny you brought this up. I was just talking to someone about a month back about this same topic. He happens to have just taken and passed the Engineers position in Greensboro. I wonder if you were both at this same drill?

Is he bad luck? You know, like a he's a jinx?

[TFD9427]

No. Real good guy. He is from up this way but migrated down there a few years ago, bringing his brother with him. He works on Quint 7. In fact, i missed a call from him last week. I usually don't like to talk to him when he calls from work and I am at work due to the fact that he has better stories and has to call me back multiple times due to interuptions (calls)

[txgp17]

No. Real good guy. He is from up this way but migrated down there a few years ago, bringing his brother with him. He works on Quint 7. In fact, i missed a call from him last week. I usually don't like to talk to him when he calls from work and I am at work due to the fact that he has better stories and has to call me back multiple times due to interuptions (calls)

You didn't catch my hint.... say it out loud.
He's a jinx, and his brother is too.

I know the older one better than the younger. The younger brother and I serve on an apparatus spec committee together. The older just got promoted to Fire Equipment Operator, official as of yesterday.

Both are good men.

[TFD9427]

Sorry, I get you now. A little slow on the uptake tonight . Also, your maintence guy is top notch. The older brother set me up with him about some questions on your quints. We are getting a Sutphen 75' w/o the bucket and he was a great help with some of the mechanical question part of our specs. Next time you see the younger one, tell him Jay from Enfield says hi.