Pumping help

[Madigad]

Can someone tell me how to use a compound gauge during pumping? What does it tell you and how do you use it while pumping...

And what is and how is direct/indirect cooling controls and how are they used?

And last series and parallel pumps, one is for pressure and one is for volume, but I can't rember which is which?

Sorry if these seem like simple questions, but I'm new and trying to learn...

Thanks

[vfdguy]

A compound gauge shows both pressure and vacuum. For example, all pumpers have a compound gauge on the pump intake. Above zero on the gauge it indicates how much pressure is coming into the pump from a hydrant or other pressurized source. Below zero, the gauge indicates vacuum in inches of mercury. The gauge will register below zero when drafting. For a better explanation refer to IFSTA's pumping apparatus driver/operator manual.

For the second part of your question, two pump stages operating in series is "pressure mode", and with the two stages operating in parallel, the pump is in "volume mode".

[the1141man]

The gauge will register below zero when drafting.

Actually, to be more accurate, the gauge will register "below zero" when displacing air from the centrifugal pump...once it "picks up" the water from the static source, the gauge will rise back up as there's no longer a vacuum in the pump.

Pretty much everything else is correct... although I'd add that just reading the IFSTA manual is a good start, but before you actually start taking on D/O duties, you need to have proper training and education in pump theory, hydraulics, your department's pumping SOGs/SOPs, and get some "hands-on time" under observation (and in controlled training circumstances--during an actual fire you need to be the one observing) from a qualified D/O before being signed off to drive/operate solo.

[vfdguy]

once it "picks up" the water from the static source, the gauge will rise back up as there's no longer a vacuum in the pump

In the interest of accuracy...as long as you are flowing water while drafting, the intake gauge will be indicating a vacuum - just how much of a vacuum will depend on the lift required, and the volume of water flowing. Watching the vacuum can be helpful in determining how close you are to pumping maximum capacity - as the vacuum reading gets close to 20 inches, you are nearing the max capacity you are able to pump in that situation.

So no, the gauge does not rise after the pump is primed, because there is still a vacuum present at the pump intake...if there was no vacuum, you wouldn't be flowing water from your static source.

[NonSurfinCaFF]

vfdguy is right, if you are drafting the pump will continue to read " of mercury, it is the discharge gauge that will show pressure once you have a good draft.

To make it more confusing I have seen many pumpers that use a compound style gauge on the discharge side as well as the intake side. Probably just a case of using the spare gauge on hand in the shop.

For the original post

Indirect cooling uses a heat exchanger next to the vehicle radiator, cool water from the pump can be circulated through this to help keep the vehicle motor from overheating during long pump ops.

Direct cooling is typically only seen on older pumpers, it allowed water from the pump to flow directly into the vehicles radiator. You had to remove the radiator cap so you would not overfill and pressurize the cooling system. Obviously these days this would not be acceptable since it would dump anti-freeze all over the ground.

vfd covered this but the easy way to remember volume (parrallel) and pressure (series) is to look at a multi stage pump. A 2 stage pump is basically 2 pumps on a shared driveline, if you run both side by side (parrallel) you get more water, if you run the 1st into the second (series) you get more pressure. Just remember parrallel lines run next to each other then series is obvious.


Kind of picking up on 1141mans comment, D/O is a big responsibility. Many people see it as the guy who gets to drive the BRT and chill while everybody else is working hard. A good D/O should always beat the hydrant man (hose connected before water can get through the hose) and should be impatiently waiting to supply water to the nozzleman. A poor D/O can kill the attack team just as well as a bad captain.

It's great to learn how the pumper works, nothing wrong with that. Just understand there is more to being a good D/O than many appreciate.

[the1141man]

Wow...man am I an idiot. Really should pay more attention to WTF I'm typing, and not base answers off my experience with a 30-yr-old pumper.

Exchanging the Apprentice (Engineer) cap for the Dunce cap now, and will bow out of this one.

[NonSurfinCaFF]

Wow...man am I an idiot. Really should pay more attention to WTF I'm typing, and not base answers off my experience with a 30-yr-old pumper.

Exchanging the Apprentice (Engineer) cap for the Dunce cap now, and will bow out of this one.

Thats ok, most people don't draft enough to be able to describe it without a panel in front of their face. I was pumping on a drill the other day with an engine I don't know well. I mentioned to the regular operator that the pressure gauge didn't work so I was having to go by just the individual discharge gauge. Then he pointed high up at the panel at the Pressure gauge which was working just fine, I was looking at discharge #4. :o

Oh, well I guess thats why captains shouldn't try to still be engineers. :)

[tomwnh]

vfd covered this but the easy way to remember volume (parrallel) and pressure (series) is to look at a multi stage pump. A 2 stage pump is basically 2 pumps on a shared driveline, if you run both side by side (parrallel) you get more water, if you run the 1st into the second (series) you get more pressure. Just remember parrallel lines run next to each other then series is obvious.


A two stage pump is one pump with two impellers not two pumps tied together. A single stage has only one impeller. The change over valve redirects the water flow to be either in series or parrallel.

[vfdguy]

Wow...man am I an idiot. Really should pay more attention to WTF I'm typing, and not base answers off my experience with a 30-yr-old pumper.

Exchanging the Apprentice (Engineer) cap for the Dunce cap now, and will bow out of this one.

Don't worry about it man....I finally got a custom fit Dunce cap because I'm wearing it so much!

[the1141man]

Oh, well I guess thats why captains shouldn't try to still be engineers. :)

Hey, in my department, they are...
Firefighters do everything but pump ops, on an unpaid basis.
Engineers are Firefighters who do pump ops, CO stuff, and get paid (most of them anyways--there are volly Engineers, like I'm training for, but not very many).
Captains are Engineers who get paid more.

Understaffing is marvelous, ain't it?

[NonSurfinCaFF]

A two stage pump is one pump with two impellers not two pumps tied together. A single stage has only one impeller. The change over valve redirects the water flow to be either in series or parrallel.

I said basically, while mechanically there is a difference in how it is done there is no difference between a 2 stage pump and 2 pumps set up in a series or parrallel pump operation.

[johnfd86]

[QUOTE=NonSurfinCaFF;794444]

To make it more confusing I have seen many pumpers that use a compound style gauge on the discharge side as well as the intake side. Probably just a case of using the spare gauge on hand in the shop. QUOTE]

I was always taught that there is a reason for this: When drafting (we removed all hard suction over 10 tears ago) and creating negative pressure inside your pump it is possible to cause damage to a regular gauge if that discharge is not fully closed (possibly due to a bad or misaligned ball valve) which sounds like a reasonable explanation.

Most departments that run two stage pumps will teach that you change over to volume (parallel) if you anticipate pumping over 50% of your rated capacity.

A couple of things not talked about, the fluid inside your gauge, usually glycerin or silicone is there to stabilize the needle and prevent freezing. In addition to the radiator filler and auxiliary cooler you have a booster cooler which circulates water from inside your pump to the booster tank to prevent your pump from overheating when not flowing water for extended periods of time.

[allineedisu]

Can someone tell me how to use a compound gauge during pumping? What does it tell you and how do you use it while pumping...

And what is and how is direct/indirect cooling controls and how are they used?

And last series and parallel pumps, one is for pressure and one is for volume, but I can't rember which is which?

Sorry if these seem like simple questions, but I'm new and trying to learn...

Thanks

You don’t say that you are a Firefighter or not.
I will take my guess and say no you aren’t, but are a want-to be!

Spend the money Son on IFSTA Pumping Practices. It has all the information that you are inquiring about.

Join a volunteer department that is progressive. That is one the makes a lot of calls and doesn’t sit in the station counting the red Ford Fairlanes that is passing by!