Ok, after all these years, I'm almost ashamed to say that I'm still confused about a simple layout plan for my sanitation hoses. I understand the basics, I'm just confused about the best placement of the directional y-valve. My system is simple. I discharge directly either to the holding tank, or to the thru-hull. There is no route from the holding tank to the thru hull (no macerater pump). Obviously, I am 99.9% routing to the holding tank. I have no problems with the pump-out hose that leads from the bottom of the holding tank. My discharge into the holding tank is at the top of the tank as is normal. I don't particularly have an odor problem, but I certainly want to eliminate all chance of odor.
So my question is, which side of the vented loop do I place the directional valve? My original layout had the valve between the toilet and the vented loop. The Raritan diagram (instructions from the new PHC - PBA that I just purchased) has the directional valve after the vented loop, so that all discharge (overboard and holding tank) has to go from the toilet over the v-loop before being directed either to the holding tank or overboard.
I'm uneasy about the Raritan diagram because doesn't that mean that holding tank odors are directly exposed and open at the v-loop? If I put the directional y-valve in front of the v-loop (between toilet and loop), then only the overboard discharge has to go over the loop (which is the only hose that needs to be protected by the loop). Discharge from the toilet goes directly to the top of the holding tank. Odors are blocked by the small amount of water that remains in the LBA (just like a normal household condition). I've noted other diagrams that show direct discharge from toilet to holding tank, without passing over vented loop.
If everybody assures me that odors do not escape from the vented loop, then I will accept that it is best. It will also make the placement of the y-valve easier for me. It was a little bit awkward the way they originally placed it. But, I thought that a vented loop is just that ... a vent. I don't want an indoor-mounted vent that releases holding tank odor into the concealed space just under the deck, behind the toilet.
So my question is, which side of the vented loop do I place the directional valve? My original layout had the valve between the toilet and the vented loop. The Raritan diagram (instructions from the new PHC - PBA that I just purchased) has the directional valve after the vented loop, so that all discharge (overboard and holding tank) has to go from the toilet over the v-loop before being directed either to the holding tank or overboard.
I'm uneasy about the Raritan diagram because doesn't that mean that holding tank odors are directly exposed and open at the v-loop? If I put the directional y-valve in front of the v-loop (between toilet and loop), then only the overboard discharge has to go over the loop (which is the only hose that needs to be protected by the loop). Discharge from the toilet goes directly to the top of the holding tank. Odors are blocked by the small amount of water that remains in the LBA (just like a normal household condition). I've noted other diagrams that show direct discharge from toilet to holding tank, without passing over vented loop.
If everybody assures me that odors do not escape from the vented loop, then I will accept that it is best. It will also make the placement of the y-valve easier for me. It was a little bit awkward the way they originally placed it. But, I thought that a vented loop is just that ... a vent. I don't want an indoor-mounted vent that releases holding tank odor into the concealed space just under the deck, behind the toilet.