Vic: a Purasan question and a suggested mod

yzer

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This Purasan works with a small water-saving manual head and raw water intake. It's been in use five or six years. I did some maintenance on the system last weekend and got everything running up to snuff. I also replaced the disinfectant cartridge.

I admit to not being as diligent as I should be regarding clear-water flushing the treatment cartridge lines and valves prior to not using the system for extended periods. As a result I got calcium deposits in the check valves 41-111 (red). I also got hard water deposits in the T-check valve 41-200 (white).

Disassembly and cleaning with an old toothbrush usually works with these valves, but this time I needed to replace one badly corroded red valve with new.

Here is where I get to the question... Is the red valve mounted on top of the treatment dispenser intended to control air pressure in the dispenser? I noticed that the dispenser acts like an accumulator when treatment fluid fills to the line. If fluid is at the fill line and I remove the red check valve I hear an air rush.

Note: the following diagrams are based upon Raritan diagrams provided for the Purasan and not actual Raritan diagrams. I'm just using these as an example. Use the actual diagrams in your Purasan manual for your maintenance, not these.

pura1a.jpg

The diagram above is my Purasan system. I use two flow restrictors instead of one. Low water flow from the water-saving manual head causes the treatment dispenser to empty faster than I can pump the head to fill it. Using some flow restriction in the dispenser return line to the treatment tank allows me to fill disinfectant to the fill line in about ten strokes of the pump. This also puts at least a quart of waste water into the treatment tank. All disinfectant drains to the treatment tank within twenty seconds.

Here is an idea that would make it easier and faster to do fresh water maintenance flushes of the dispenser lines and check valves. This mod would eliminate the need to remove hoses from the base of the dispenser (and the drippage) and use of the second red check valve and short hose for this purpose. All you would need for this mod is a small pair of corrosive-resistant plastic diverter valves with hose bibs and a variable length of interconnecting hose.

pura1ab.jpg
pura1aC.jpg
 
Yzer, I don't see why your idea wouldn't work, provided you can find the referenced valves (perhaps from a chemical supply house).

Another issue, you aren't supposed to use that version of the Purasan with a manual toilet; it isn't supposed to work...

With a manual toilet, you're supposed to use the PST1203, that has the solenoid valve that ties into your pressure water system, to supply water to the Purasan dispenser.

I'm surprised that it works...! (but you can't argue with success).
 
I think Raritan gave up on using Purasan without a pressurized water system sometime after I purchased the unit. It does work reliably as installed on my boat but operation with manual toilet that was designed pump as little water as possible (a plus for holding tank systems) gets tricky. I can't help but think a Purasan operating off a manual toilet with a larger capacity pump cylinder would do great.

The head I'm using now went out of production last winter. Because the entire sanitation system is shoehorned into such a small area it's going to be a major pain to install any other head that doesn't have exactly the same footprint. I'm going to make the current head last as long as posssible. I've got one rebuild kit left for it.

Regarding valves for the mod idea. Yes, I know some people who work in labs and will try to get hold of a catalog. If someone makes those exotic litle check valves for the Purasan then simple diverter valves should be easy.
 
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