Plumbing from Scratch - How to Proceed

[Rugger8]

I have a 46' 1947 Chris Craft that I bought a couple of years ago and am in the process of updating all of the systems in her. The head was a direct outlet with a lectrasan purification system, but with no holding tank. So, I am in the process of upgrading the main head. I have already purchased a Raritan Elegance toilet that will be fed from the freshwater system in the boat. I am trying to design the rest of the system. So, here are some of my questions.

1. I can use either 1" or 1.5" sanitation hose to the holding tank, positives negatives for either one and which sanitation hose is the best?

2. Which holding tank manufacturer? I was looking at Ronco and Raritan.

3. The holding tank is going to be placed in the center of the bilge, essentially between the two engines. Where is the best place to put the inlet, outlet, and vent fixtures?

4. The vent line should be at least 1" and ran horizontally as short a distance as possible. From the center of my boat to the outside, will be around 5.5'? Is that acceptable or should I run it into a closet next to the tank around 2'?

5. What would require a vent loop? The holding tank will be slightly below the toilet, but is right around the water line of the boat.

Finally, this is a power boat, so does not get the same extreme lean as a sailboat.

Thanks for your replies!

Jeff

[peghall]

How old is the Lectra/San? And why would you scrap it?

1. I can use either 1" or 1.5" sanitation hose to the holding tank, positives negatives for either one and which sanitation hose is the best

Go with 1.5"...it's the standard size that every equipment mfr BUT Jabsco uses...so any y-valves, vented loops etc would need reducing adapters if you go with 1'.

2. Which holding tank manufacturer? I was looking at Ronco and Raritan.

Ronco Plastics is your best source. They supply most of Raritan's tanks...you can buy direct from Ronco for a LOT less $$.

3. The holding tank is going to be placed in the center of the bilge, essentially between the two engines. Where is the best place to put the inlet, outlet, and vent fixtures?

Not a good location for several reasons, not the least of which is heat from the engines. There are several much better places...email me...we'll discuss your options.

4. The vent line should be at least 1" and ran horizontally as short a distance as possible. From the center of my boat to the outside, will be around 5.5'? Is that acceptable or should I run it into a closet next to the tank around 2'?

A 2' line is MUCH better than a 5'. However, waste tanks MUST be vented to the outside of the boat...so you can run a vent line THROUGH a locker to the hull, but it can't terminate in the locker.
We'll decide where to run the vent after we figure out where to put the tank.

5. What would require a vent loop? The holding tank will be slightly below the toilet, but is right around the water line of the boat.

Since the Elegance is designed to use pressurized flush water, you may not need any vented loops unless you keep the LS and/or plumb the tank to dump it at sea.

Give me a shout...I'd love to help you work out a system that'll be trouble free AND odor free with minimal maintenance.

[sdowney717]

I lean towards having a waste tank self empty by gravity with no pump needed.
So the tank would be above the waterline, not in the bilge and a thru hull comes out the tank at bottom (low on side or bottom of tank) and empties right into the sea.
Advantage is it just works by gravity, no need to buy or maintain a pump.
Disadvantage, you have to open the thru hull, which you likely would have to do anyway when using a pump.

I also would make my own tank to properly use the available space.
Short hoses much better. And thinking solid PVC pipe if possible, I hear they dont permeate odors like rubber hoses.

Perhaps if the Lectrsan kills the bacteria, then waste goes into the tank, you wont have much odor trouble?

I wonder how high an electric toilet can pump the waste in filling the tank. My own system raises the waste about 6 inches no problem.

What type of tank level monitor are you going to use?