3" vs 4" Tank to Pump

[jray]

Looking at purchasing a water tanker/ tender. Have a question and was wondering if anyone out there could help me out? We are looking at a darley hm500 gpm or darley psp 1250 gpm pump. Can anyone tell me the flow rates of a 3" vs 4" tank to pump for both of these pumps? If so is there a chart I could find this info on? Thanks

[bigjim54]

The quick answer is get the 3" with the 500 and the 4" with the 1250.

[GTRider245]

I am sure Darley should be able to tell you. If memory serves me correctly NFPA requires a 600 GPM tank to pump valve on 1250 GPM pumps. Not sure what size that would equate to though.

[16Scott]

The 3" will be plenty to handle the 500 GPM pump capacity.

Our 750 GPM pump equipped tankers (some are Hale, some are Waterous) have 4" tank to pump piping and will flow 950 GPM from the tank. I do not know the pump models but they are mid-ship single stage with a 4.5 steamer on each side, PTO driven.

What I have found is keep the pipe short and straight - tight turns will affect flow.

[HuntPA]

Easier way, and what we did on ours. . . . . .
Spec that the pump must be able to operate at capacity from the tank. We have a 1500 gpm pump and they gave us (2) 4" lines with 3" valves. We let them do the calculations and the plumbing and also take the responsibility.

[GTRider245]

Easier way, and what we did on ours. . . . . .
Spec that the pump must be able to operate at capacity from the tank. We have a 1500 gpm pump and they gave us (2) 4" lines with 3" valves. We let them do the calculations and the plumbing and also take the responsibility.

Only because I have never heard of this, why would you ever need a pump that could reach capacity from tank water?

[HuntPA]

We use this as a tanker, a pumper, and a nurse tanker all depending on the situation. If we are hooked to our engine (1500 gpm) and using the deck gun on the engine, we want to be able to supply it with the tanker water to save the engine water for hand lines on a quick hit.

In other words, if we roll up on a fully involved single family dwelling with all occupants out, we can lay in with the LDH on the engine, attach to the LDH discharge on the tanker, and use the deck gun for a quick knock down while setting up for drafting operations or have the tank used as a nurse tank from other incoming units.

[ffp20]

if it seems to work fine, or better when flowing larger volumes, it may be an indication "ramp" adjustments may need to be made.

[ffp20]

sorry, my message above was supposed to be on another thread...duh

[jeepsterdufus]

sorry, my message above was supposed to be on another thread...duh

That's ok, it sounded impressive.

[GTRider245]

We use this as a tanker, a pumper, and a nurse tanker all depending on the situation. If we are hooked to our engine (1500 gpm) and using the deck gun on the engine, we want to be able to supply it with the tanker water to save the engine water for hand lines on a quick hit.

In other words, if we roll up on a fully involved single family dwelling with all occupants out, we can lay in with the LDH on the engine, attach to the LDH discharge on the tanker, and use the deck gun for a quick knock down while setting up for drafting operations or have the tank used as a nurse tank from other incoming units.

Still not following. Around here if we were to blitz attack with the deck gun off of tank water we would looking at around 500 GPM. How much water is on your engine?

[RFDACM02]

Only because I have never heard of this, why would you ever need a pump that could reach capacity from tank water?

If you have an around the pump Class B foam system. In this case, you cannot supply the pump from a positive water source, unless you put the water straight into the tank, then pull it from the tank. Two of our engines are set up this way to flow capacity for that reason.

[ffp20]

on a rig we had the around the pump proportioner, we used 2 4" tank to pump lines. we were able to make 1400 gpm of solution with it.

[HuntPA]

Still not following. Around here if we were to blitz attack with the deck gun off of tank water we would looking at around 500 GPM. How much water is on your engine?

We have 2 tips for our deck gun, a 500 and a 1250.

Our engine carries 1,000 gallons of water.

[GTRider245]

If you have an around the pump Class B foam system. In this case, you cannot supply the pump from a positive water source, unless you put the water straight into the tank, then pull it from the tank. Two of our engines are set up this way to flow capacity for that reason.

I completely forgot about this. Being as these systems are not prevelant around here I never think about them. Our newest engine has a direct tank fill that was factory (we didn't spec it); I am assuming because so many trucks are going with the CAFS systems and the like that they just started putting the tank fills on all the trucks.

[jeremy1213]

on both of our pumper tanker's they have 4inch tank to pumps. one is a 500 front mount and the other is a 750 watours with caf's midship pump

[txgp17]

The Tank to Pump line is the only place where you can have a valve larger than 3½" and not have a slow-close mechanism. So upgrading a P2T line from 3" to 4" wouldn't be expensive compared to the same action for an intake or discharge.

I'd go with the 4".

[SuperFire]

4" is better then 3". 4" is give better flow then 3" pipe.

[npfd801]

4" is better then 3". 4" is give better flow then 3" pipe.

Unless you can justify the need, it costs. If you're really going to flow what a 4" tank to pump is going to give you off of the actual tank water, then go for it.

As a guy that sells the stuff, it really adds up when you have $500 here, $1,000 there in options that you really maybe will use once or twice in a rig's life.

[FyredUp]

Unless you can justify the need, it costs. If you're really going to flow what a 4" tank to pump is going to give you off of the actual tank water, then go for it.

As a guy that sells the stuff, it really adds up when you have $500 here, $1,000 there in options that you really maybe will use once or twice in a rig's life.

We went with a 4 inch line on our newest pumper. Why? We wanted to be able to flow a minimum of 1000 gpm from the tank for Blitz attacks with either the deck gun or multiple handlines. We figured that by the time we dumped the tank we would have a water supply established either from a hydant of shuttle.

Minimum staffing allowing for maximum water.