55fossil, I forgot to mention the pressure control valve - thanks. I'd like to post an image but it's such a strung-out system it's hard to photograph so I'll describe what I did.
To catch up with current comments, I’ve never experienced a problem I can attribute to cross-contamination, either with the old pump system or my new one. My own opinion is that it’s mainly an imaginary problem for those using Nova-type soft wheels. I get scratches but I can always trace them to my own error, usually from getting in a hurry or not drying out a stone and inspecting it with a loupe to make sure there are now problems before going on to the next grit. I'm not scrupulous about keeping my machine clean either.
I cut with a Genie I bought gently used in 1989 – no experience with the newer models. It’s a great machine but the Genie has 2 major weaknesses as I see it. First is the junky OEM particle board base that rots and warps quickly and second is the pump. I replaced the base on mine with a waterproof polyethylene cutting board but the pump was a constant problem so I decided to bypass it.
I tapped into my water heater's inlet cold water line and ran a long plastic line over a bank of cabinets to the pressure valve near the cab machine. There are several ways to tap into the line and a plumber may be needed depending on individual situations. I used a self-tapping gizmo I bought at the local hardware store like this:
Tapper.jpg (7.95 kB . 272x272 - viewed 307 times) Mine is a slightly heavier-duty version but this illustrates the principle.
I use a simple needle valve to regulate pressure:
Valve.jpg (7.66 kB . 272x272 - viewed 327 times)To hold the pressure valve in-line I removed the nuts shown above and substituted barbed fittings at the inlet/outlet ends and secured them with small hose clamps. I used appropriately-sized fittings similar to the one shown at bottom left here:
Brass-fitting-air-hose-connector-brass-hose_jpg_640x640 (200x200).jpg (40.53 kB . 200x200 - viewed 289 times) I searched for a reducer to adapt from the 3/8 OD/1/4 ID plastic supply line to the smaller Genie spitter line but couldn't find anything that would work. I found that the smaller line fit fairly snugly inside the supply line so I jammed it in, let it dry out completely, then 5-minute-epoxied the heck out of it. Twice. It’s a sloppy solution but it works and that’s all I ask. I'm sure others will find a better method.
I drilled holes at the back bottom of the splash pans and epoxied these things in (don’t know what they’re called). Your hardware man will know.
001 (150x125).jpg (30.6 kB . 150x125 - viewed 280 times) When the epoxy set up I attached drain lines to the above hardware and ran it to my catch pail. I use a 5-gallon bucket and find I need to drain it with my submersible pump a couple of times each 2 or 3-hour cutting session. As mentioned earlier, I don’t have a drain in my shop so I drilled a hole through the wall and ran a drain line from my pump to a nearby outdoor rain drain. But every situation will be different.
If I was doing it again I think I’d tap into the hot water line or find some way to warm the cold water – even here in “sunny” CA it gets darned cold and winter cutting can be uncomfortable on the hands with my system. Any suggestions to warm the water would be welcomed.
Hope this makes sense and helps someone.