[MarineMachinist]

I am having a major PITA with this machine and its abrasive feeding... It will cut ok for a few minutes, then shoot water up the abrasive feed tube, getting all the internals inside the feed element all wet...

I have taken it apart several times, cleaned it, dried it, changed the disc, nozzle, and mixing element, put it all back, and still continues to harass me with this crap!

PLEASE HELP!

Thanks

Brad

[Signmaker]

Easy fix.... get yourself an inline back flow valve.

Simply cut the garnet feed hose running between the garnet dispenser and the mixing chamber and plumb in the valve.

In normal conditions the ball is held over the valve allowing the garnet to flow down to the mixing chamber.... .if you get a blockage water will shoot up the garnet hose, force the plastic ball to rise and the water is immediately diverted sideways out of the hose BEFORE it gets to the garnet dispenser.

These valves are pretty cheap and very easy to install.... I think ours is from IWP, I don't know exactly how much they cost.... our part supplier just gave us a box full... this leads me to think they must be dirty cheap.

[jet2009]

Hi there,
whats happening to you is that you might be cutting to close to the workpiece and if not, the other thing might be that you have crap on your garnet making your nozzle get clogged! try checking your cutting height and give a quick look to any bigger particle that might be on your garnet!

[MarineMachinist]

Easy fix.... get yourself an inline back flow valve.

Simply cut the garnet feed hose running between the garnet dispenser and the mixing chamber and plumb in the valve.

In normal conditions the ball is held over the valve allowing the garnet to flow down to the mixing chamber.... .if you get a blockage water will shoot up the garnet hose, force the plastic ball to rise and the water is immediately diverted sideways out of the hose BEFORE it gets to the garnet dispenser.

These valves are pretty cheap and very easy to install.... I think ours is from IWP, I don't know exactly how much they cost.... our part supplier just gave us a box full... this leads me to think they must be dirty cheap.

Thank you for your words of encouragement! I was very frustrated to say the least! Do you have a part # for the back valve?

[MarineMachinist]

Hi there,
whats happening to you is that you might be cutting to close to the workpiece and if not, the other thing might be that you have crap on your garnet making your nozzle get clogged! try checking your cutting height and give a quick look to any bigger particle that might be on your garnet!

I will istall the valve mentioned by signmaker, but I believe you are definitely onto something! Like I said, I am new to waterjets, and shockingly, NOONE in the shop knows jack about it, and show very little interest in learning. All that I know about it is all self taught by fiddling with it and putting my nose in the manuals.

What should the ideal nozzle offset be then, I believe I had it set at approx 1/16 to 1/8 inch.

Thanks!!

[MarineMachinist]

Hi there,
whats happening to you is that you might be cutting to close to the workpiece and if not, the other thing might be that you have crap on your garnet making your nozzle get clogged! try checking your cutting height and give a quick look to any bigger particle that might be on your garnet!

I took the splash gaurd off today, and set the nozzle offset at about 1/4"... now its running beautifully!

Thanks again for the tip!

Brad

[Hack]

We have had this problem on a few occasions with our Flow 87k Waterjet. Turns out there is a diaphram that occasionally gets a pin hole in there and causes this exact problem. This diaphram acts similar to a check valve in a round about way.

Sounds as if you may have solved the problem, but if not and you continue to have issues, drop me a line and i will help you the best I can. We have had ours for about 2 years and have had enough time to learn it quite well. We average about 18 hours a day 5 days a week on ours so we use alot.

We have an auto height setter on ours tor esolve the cutting height issue.

Dan

[Signmaker]

I checked our valve and there is no part number on it

If you go to iwpwaterjet.com you'll find the valve listed under abrasive handling... it's called a Snorkel or anti back wash device.

List price is $135.00.... bit of a surprise seeing as my supplier gave me a snorkel for nothing.

Anyway, whatever machine you are running I would strongly recommend you get a snorkel.... they are a guaranteed solution which eliminates the possibility of water getting into your garnet hopper.