Thread: Jet Dump on Tankers
08-21-1999, 05:21 PM #1CAPTAIN GFirehouse.com Guest
Jet Dump on Tankers
I'm searching for ideas about jet dumps on tankers. Any info you have would be appreciated. I'm curious about the time it saves, as well as how to set up or build. Thanks for any info provided.
08-22-1999, 09:34 PM #2FyredUpFirehouse.com Guest
Why add the complexity of a jet dump? If you go with a 10 or 12 inch Newton square dump you will dump in excess of 1000gpm,(I don't know the exact figure off the top of my head) with out having to do additional plumbing or put the pump in gear.
08-23-1999, 11:34 AM #3BURNSEMSFirehouse.com Guest
Our Dept recently added a Newton Dump on our 1650 gal Tanker we can empty the entire Contents in approx 3 min along with our 2000gal porta tank we have improved our rural water supply 100% compared to before, I am not sure about Jet Dumps however just a Simple Dump Valve is a Great addition to any Tanker and will save you alot of time on Water Shuttels in the rural Enviroment.
Here today for a Safer Tomorrow
08-24-1999, 08:49 AM #4CAPTAIN GFirehouse.com Guest
Thanks for the replies. I keep hearing about them, but no one I talked to really knew too much about them. We currently use 12 inch dumps now, sounds like thats all we need. Thanks again.
08-24-1999, 09:49 AM #5eppieFirehouse.com Guest
You can try Mike Wilbur if you want some good information with jet dumps etc... He does an excellent water supply course and gets pretty in depth with different supply ideas.
His business number and address are below.
Emergency Vehicle Response
121 Whitlock Road
Otisville, NY 10963
08-28-1999, 04:28 PM #6721Firehouse.com Guest
Out 1200 gallon tanker with jet dump, dumps in 45 seconds via a 6" valve with 4' extension tube.
That is about 1600GPM dump.
Remember that a tanker is ONLY doing it job when the wheels are turning. Fill and dump times are wasted time.
09-06-1999, 04:51 PM #7NickFirehouse.com Guest
I would have to agree with 721. Take a look at vacuum tankers, they can be speced with pump and roll capabilities, dump and fill at 1200+ gpm through 6" plumbing, and be filled at both pressurized and non-pressurized water sources (aka. hydrant and pond).
09-07-1999, 08:02 AM #8Jim M.Firehouse.com Guest
Our 1800 gallon tanker can offload in 60 seconds with the jet dump, about 3 minutes with just the 8 inch dump valve. Next time, I would eliminate the jet and just go with the larger Newton - probably a 10 or 12. Less plumbing and one less step for someone to remember in the middle of the night.
10-09-1999, 05:55 PM #9smokey stoverFirehouse.com Guest
My understanding of a "jet dump" is that is works on the venturi principle. There is a discharge mounted in the tank that lines up with the opening of the dump mouth. When you open your dump valve and then pump through the jet dump discharge, you create the venturi which draws more water into the dump. I cannot remember if the jet dump discharge is 1" or 1.5". We have a tanker with a jet dump and one with a Newton quick dump. I agree the jet dump takes quite a bit more time to set up. Engage Pump; open tank to pump; open jet dump valve, throttle up; throttle down due to over-shooting fold-a-tank. It will definitely empty tank quicker than gravity but only after the above steps.
10-09-1999, 11:46 PM #10721Firehouse.com Guest
Smokey, you are right about the venturi function of jet dumps. Last tanker that I actually knew the size of the jet dump line in the tank, was a 1.5" that tapered to 1.25".
During first dump on a water shuttle operation the driver backs in, engages the pump then gets out and pulls tank suction, and jet dump, and throttles up to dump. The second man on the truck, who was spotter for backing up to the tank, sticks the 4' extension tube in the discharge and opens the 1/4 turn valve. While dumping, the driver/pump operator should notice the RPM's on the tach.
When empty, driver throttles down, and 2nd man closes the 1/4 turn valve. Leave the extension tube in place, and tank suction and jet dump valves open. After filling and returning with another load, back up to tank, set brake, engage pump, and throttle up to RPM's noticed on first dump. 2nd man who backed you in again also operates the 1/4 turn valve.
The driver can see the water level in the dump tank in the mirrors, and on both of our tankers can see the tank level indicator lights in the mirror also.
Not as slick and fancy as pneumatic operated dump, but you better have a spotter everytime you back a tanker up to a tank, and the spotter can operate the valve.
We have found the secret to successful jetdump operations is to have extension tubes for every tanker. First you don't have to get right up to the tank, and it eliminates any overshoot of the tank, expically when the tanker is almost empty.
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