Thread: More CAFS questions
08-28-2002, 04:53 PM #1
- Join Date
- Feb 2002
- Saginaw, Tx
More CAFS questions
I would like to get some ideas on specifying CAFS on a new engine. I was thinking of the following discharges with CAFS: 2" front bumper, 2" front bumper electric turret, one 1 3/4" crosslay, deckgun, one 2 1/2" preconnect
I am looking at a 200 CFM compressor at a minimum. I know Darley makes on a little bigger. I also know that all of the above discharges cannot utilize CAFS at the same time.
I am not sure how many discharges can be plumbed with CAFS.
Also, I saw in Kansas City that Hale is back in the CAFS business after their first crack at it failed. What has been your experience with different makers ie.: Darley, Waterous, Hale:
08-28-2002, 05:52 PM #2
- Join Date
- Aug 2000
- South St. Paul, MN
200 CFM compressor size is the standard. I have (1) front bumper, 2-1-3/4" crosslays, and (1) 2-1/2 preconect on two of my trucks. I am not a big fan of plumbing the deck gun. The deck gun requires a static mixer and usually a seperate plumbed plain water discharge because of the losses in the mixer and the foam manifold. I have had 3-1 3/4" and a 2 1/2" flowing at one time. The 1 3/4" will use about 35-40 CFM and the 2 1/2" 80-100 CFM. In lieu of a deck gun I would use the 2 1/2" in the direct tower feed or a portable moniter. The number of discharges plumbed with CAFS is really only limited by space and cost.
08-30-2002, 12:08 PM #3
Greg, we have the deck gun, no extra mixer just a stream straightener and it works fine. Having the second feed of straight water allows you to flow the deck gun and not waste CAFS while also feeding a hand line. 2ea 2 1/2's and 1 3/4 preconnects with one 2 1/2 discharge and one 4" discharge CAFS capable. We have one 2 1/2 water only preconnect for fog use and two more water only discharges.
Things that I would include next time...
1)The ability to turn off the foam feed to the 4" discharge, that will allow you to feed another pump and run CAFS in handlines (we have done this at an industrial fire) The foam is fed via point of discharge distribution so it is feasable. We want to be able to feed the tower pipe with CAFS or a remote deck gun, but we also need to be able to feed another pump (almost ran foam into another engine in training once).
2)A training foam feeder. Class A is expensive, if there were an external pick up that you could run cheap foam (say a 5 gal bucket of compatable training foam or even Joy liquid soap) through to get training CAFS you'd save yourself a bundle in training costs. This could also serve as a back up if you run out, gel up, or accidentally dump the onboard tank.
09-01-2002, 12:49 PM #4
- Join Date
- Jan 1999
- North East Wi. USA
We run CAFS on our 2 front bumper preconnects , and four rear preconects and have the deck gun dual plumbed. We set ours up for what we needed not what the capacity of the unit was. I feel the limiting factors to be the size of the compressor and the size of the foam manifold you specify. We have the larger Foam Pro 2002 but can easily set up for more flow then the manifold will let through. We have additional discharges that are water only so we are not limited and have dual plumbed our deck gun 3" CAFS ( No static mixer) and 4" water only. The waterous eclipse system can be plumbed to five discharge, ours in a pneumax compressor with a Hale pump and was plumbed to as many discharges as we wanted, ( understanding that the compressor has a limit) to give us the flexability down the road.
09-04-2002, 01:11 PM #5
- Join Date
- Dec 1998
- Sunnyvale, Tx
The discharge specs you have noted should be sufficient. BTW Hale got out of the CAFS biz for other reasons, not that they failed but that it was not cost effective for them. We have a 2000 Ferrara Hale CAFSMASTER system that will shoot foam with the best. It did not come out of the factory box but the key is it works and is pretty easy to operate. Hale should've learned a few things while tweaking our unit and working with our Chief who had built a couple of large CAFS units himself. We are just on the east side of the DFW Metromess, so come on by if you want to see a few different setups. We have 4 units and 3 different design/makes. Be Safe and keep putting the white stuff on the red stuff.
Sunnyvale Volunteer Fire Rescue
09-05-2002, 09:33 PM #6
- Join Date
- Jan 2001
- Madison, NJ USA
Our department is using a Pneumax PTO CAFS system on a Hale Pump. Works great, been using it since 1998. If I had to do it again I would stay with Pnuemax however I would go with an Eclipse from Waterous. The Eclipse CAFS is a Waterous pump with the Pneumax system, which also includes a FoamPro proportioner and the most important thing TRAINING. You get a trainer that comes to your station and trains your department on how to operate and use CAFS, when the apparatus is delivered. The Eclipse is assembled, tested, and certfied prior to leaving the Waterous factory.
We have six discharges plumbed for CAFS. A 200 cfm, PTO air compressor and a 2002 foampro pump. One of the discharges is a deckgun and we did have it dual plumped. This is for water only GPM flow purposes and would recommend it. We also have 3 – 2 1/2“ water only discharges and 1 – 4” water only discharge. We as a department know we cannot flow CAFS through all of the plumbed foam lines simultaneously. We know we can flow 3 - 1 3/4" lines or 1 - 2 1/2" and 1 - 1 3/4" lines or the deck gun only or feed our aerial only. One 1 ¾” CAFS handline seems to be doing the job for us on most fires.
I'm not to familiar with the Darley system, but the Hale system cannot pump air only from the foam capable discharges like the Pneumax. This is useful for blowing water out of the hose after flushing for easier cleanup. It can also be used for air tools, ice rescue and booming, all with fire hose. The Pneumax system can also flow foam solution from one line and CAFS from another at the same time. The Hale can only flow one or the other. The Pneumax gives you, the user more “tools in the toolbox”.
One topic that needs to be discussed is the water intake psi supplied to the fire pump. A CAFS handline is easily manageable at 80 to 100 psi, with a maximum of 150 psi. Remember. in order to make CAFS the main water discharge psi and air psi stay pretty much equal. The air psi output is set to a maximum of 150 psi. If you are connected to a “hot” hydrant, it can cause you problems. If you are connected to a hydrant above 50 psi, which in my town all are and some as much as 130psi, problems will be encountered. If the pressure is to close to that 80 to 100 range, then you cannot get enough rpm's to spin the compressor fast enough to make a large enough volume of air for multiple handlines. If you run the rpm's up, up goes the water and air psi. If it goes above 100 psi the handline becomes hard to hold and manage. And if the water pressure goes above 150 psi, CAFS will not be made. However there are a few solutions to this problem. 1. Work off the booster tank only. However if you need to refill the tank off a “hot” hydrant it may run the pressure up to high. 2. Have a 2 ½” direct fill into your booster tank. The pump operator has to pay attention and manually open and close the valve as needed, but it works. 3. Same scenario as number 2 but use an electric auto tank fill valve. The valves are pricey, but work. 4. There is a pressure reducing valve that is very simple and almost “fireman proof”. It reduces incoming pressure to a minimum of 15 psi without affecting gpm flow. Once the psi is set, and you can preset the valve to 15 psi or what ever is desired, it will not matter if you hit a hydrant with 50 psi or 150 psi, it only allows the psi you set to pass through. It comes in 3 and 4 inch size valves and probably larger if needed. It can be built into the apparatus supply plumbing or there is a portable valve with your fire threads on it. The valve also has a bypass selector to bypass the psi setting if needed. Again, this valve reduces psi without reducing the gpm flow.
The other thing I would recommend is a pressure governor. But spec one that defaults to pressure when the pump is engaged. On some of the units you have you push two or three buttons to get to the pressure mode. Not very fireman friendly.
Nozzles are another important part of the operation. An 1 3/8” ball valve with a 15/16” tip works best for an 1 ¾” attack line. We use the breakaway type nozzles so we can remove the tip or change it as needed without shutting down the line. These nozzles also work well when the charged line needs to be extended because the open bail end of the nozzle is an 1 ½” fire hose thread. Just grab more hose and another nozzle and your good to go.
Hope I haven’t confused you to much. Good luck.
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