Combination vs Smoothbore...THATS RIGHT!

[ENG27SQ]

It's time to get this forum back to where it was, when we were replying information for all of us to learn from..so let's debate

I know the topic of combo nozzles vs smooth bore nozzles is ALWAYS out there, so, let us discuss...

What is your opinion on both, what do you prefer, what does your company/department use, and most importantly, WHY?

[fireman1190]

My department uses mostly task force nozzles but they've started using some more smooth bores on the crosslays as well now.

My other department in WV uses all combination nozzles.

i prefer the flexibility of a combo nozzle. i like the ability to control the pattern.
However, I think we can't deny the deeper penetration offered by a smooth bore.

I know personally I've been on a few fires where it seemed like the combination nozzle just didn't cut it. But then again, we may have just had too much fire.

I've only been doing this a few years so I'll let the experts chime in.

[WebBoss]

Jan 12, 2009 15:15:40 GMT -5 fireman1190 said:

My department uses mostly task force nozzles but they've started using some more smooth bores on the crosslays as well now.

My other department in WV uses all combination nozzles.

i prefer the flexibility of a combo nozzle. i like the ability to control the pattern.
However, I think we can't deny the deeper penetration offered by a smooth bore.

I know personally I've been on a few fires where it seemed like the combination nozzle just didn't cut it. But then again, we may have just had too much fire.

I've only been doing this a few years so I'll let the experts chime in.

We run with Akron Saberjet "Combination" tips on our 1 3/4" crosslays, 15/16 smoothbore tips on our 2" crosslays, and Akron automatic fog tips on the front bumper lines. We also run 15/16" SB tips in all of our highrise bags as well.

So far, it's a great mix. The Saberjet's are rarely used for anything other then smoothbores, but it's nice to have the flexibility there.

With all automatic nozzles, it's always better to err on the high side of the pump pressures, giving you more water. It's simply amazing the difference in knock down potential between a nozzle with poor friction-loss mathmatics only getting 85-95psi at the tip, and one with good friction-loss compensation getting 100-110psi at the tip. When an automatic nozzle's spring is set for 100psi, it needs AT LEAST 100psi... 99psi isn't enough to fully open the spring and let the full potential of the water flow.

Just my little rant on nozzle pressures... lol I am a self proclaimed "Water Flow Nazi" of sorts when it comes to this kind of stuff.

While we're at this, does anyone have access to a machine shop? I would like to cut an older automatic nozzle in half lengthwise for teaching purposes.

[fireman1190]

Jan 13, 2009 10:37:09 GMT -5 WebBoss said:

Jan 12, 2009 15:15:40 GMT -5 fireman1190 said:

While we're at this, does anyone have access to a machine shop? I would like to cut an older automatic nozzle in half lengthwise for teaching purposes.

I would like to see that!

is the Saberjet the one that can be a fog or a smoothbore? or is that the Turbojet?

I forgot to mention we do have those on one of our engines in WV and I do not like them. Their operation is counterintuitive to anyone trained on a regular nozzle. However, I guess more training is always the answer to that problem.

[papacheese]

I am in complete agreement with the Boss regarding nozzle pressures for automatics - up to a point.

As he alludes, most automatics are designed to operate correctly at 100 psi nozzle pressure. Not ENGINE pressure, mind you, but nozzle pressure....you have to do the math to figure out the friction loss for your particular hose set up.

The point I want to make is don't fall into the trap of equating one psi to one gallon per minute, as some do. In other words, more pressure can equal more water, BUT ONLY UP TO POINT, when the friction loss in the hose begins to restrict water flow instead of increase it. The pressure/volume graph is bell-shaped...which means at some point, the more pressure you put on a line, the less water comes out.

Here in McMansionland, we have switched over to a smoothbore on the passenger side preconnect and an Akron Sabre Jet on the driver's side. To date I've heard no complaints over this selection and beleive it's a good combination to have. Most of you have no doubt read my previously posted thoughts on automatic versus smoothbore, so you know I believe there's a place for both in our toolbox, depending on circumstances. Just don't fall into the trap of thinking they are tactically the same, because they're not....

[ENG27SQ]

Jan 13, 2009 10:37:09 GMT -5 WebBoss said:

Jan 12, 2009 15:15:40 GMT -5 fireman1190 said:

My department uses mostly task force nozzles but they've started using some more smooth bores on the crosslays as well now.

My other department in WV uses all combination nozzles.

i prefer the flexibility of a combo nozzle. i like the ability to control the pattern.
However, I think we can't deny the deeper penetration offered by a smooth bore.

I know personally I've been on a few fires where it seemed like the combination nozzle just didn't cut it. But then again, we may have just had too much fire.

I've only been doing this a few years so I'll let the experts chime in.

We run with Akron Saberjet "Combination" tips on our 1 3/4" crosslays, 15/16 smoothbore tips on our 2" crosslays, and Akron automatic fog tips on the front bumper lines. We also run 15/16" SB tips in all of our highrise bags as well.

So far, it's a great mix. The Saberjet's are rarely used for anything other then smoothbores, but it's nice to have the flexibility there.

With all automatic nozzles, it's always better to err on the high side of the pump pressures, giving you more water. It's simply amazing the difference in knock down potential between a nozzle with poor friction-loss mathmatics only getting 85-95psi at the tip, and one with good friction-loss compensation getting 100-110psi at the tip. When an automatic nozzle's spring is set for 100psi, it needs AT LEAST 100psi... 99psi isn't enough to fully open the spring and let the full potential of the water flow.

Just my little rant on nozzle pressures... lol I am a self proclaimed "Water Flow Nazi" of sorts when it comes to this kind of stuff.

While we're at this, does anyone have access to a machine shop? I would like to cut an older automatic nozzle in half lengthwise for teaching purposes.

2900 owns a machine shop in Pennsauken, not sure if they can cut it in half, but you should try to e-mail him.

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