Do I Really Need a Diverter Valve ?

[off-the-grid]

A few months back, I thought I had a clog somewhere (turned out to be a hairline crack in one of the fittings). Anyway I redid some of my pluming at the time, and made the stupid newbie mistake (depending on the answers I get to this) of throwing out the old valves. On the other hand, a few less connections and one less part to fail is always a plus in my book.

The head goes directly to the holding tank, and the holding tank goes directly to the thru-hull. Thru-hull is a little less than a foot below the water line, and the holding tank is more than a foot (maybe close to 2 feet) above the waterline.

Also, I have a small pad lock on the thru-hull handle, which should meet regulations, which say that the valve needs to be secured, but not that you need Y-valve in addition to the thru-hull.

Type III MSDs having a through hull Y valve must only be opened when the vessel is offshore, beyond the limit of U.S. territorial waters. At all other times, the valve must be positively secured in a way that presents a physical barrier to valve use and prevents all discharges. Adequate means include the use of padlock, non-releasable wire-tie, or removal of the valve handle. For more information see 33 CFR 159.7.

The only problems I could see is:
Maybe shorter lifespan before the hoses start to stink, and needing more frequent cleanings from always having waste water in them.
Pump out may not be able to get that last little bit that's down near the thru-hull (just guessing).

[capt_douglas]

Since your MSD doesn't have a "Y" valve, I'd think locking off the valve you have would be OK with the Coast Guard. The main idea is to prevent overboard discharge and since your system has only one way to go, you're OK there.

For many of us, the virtue of a "Y" valve is that the holding tank can be flushed out at sea thereby reducing the chances of odors getting into the hosing and vessel.

The only question I have is how do your pump out the holding tank if, as you say, the head goes to the holding tank which goes to the overboard discharge when you're in an area where you need to lock off the overboard discharge? Wouldn't you still need a "Y" valves so you could divert the product to a deck fitting?

[off-the-grid]

Oops very important detail not explained correctly.

The tank has a T fitting (installed by PCI), with one end of the T directly to the deck pump out, and the other directly to the thru-hull.

[Watercolor]

If your going to the Great lakes (especially Canadian waters) or Lake Champlain the law states that you need to have your discharge line completely removed from the through-hull. This was as of several years ago. There may be more locations that now require complete disconnection of the waste discharge system. There are devices to facilitate this issue and improve access to the clogged lines.

[Hudson Force]

Here is a sketch of the plumbing for my forward head and holding tank that has been serving me without problems for the last ten years:



I have no Y-valve and one is not needed at the T where the contents of the tank may be pumped out through the deck or expelled via the macerator. I have a pad-lock on the cabinet & the through hull handle remove while it is set in the closed position. My system has been approved on two courtesy USCG auxillary inspections as well as by the Florida Marine Patrol. Take care and joy, Aythya crew

[foggysail]

I took the easy way out that I believe satisfies all requirements except those mentioned by others regarding the great lakes.

My macerator is powered via a circuit breaker but in series with the breaker I have a key switch. The key is kept in a safe place so there is no way to energize the macerator without my knowledge.

This much for sure, a key switch for the electrical power is far easier to lock and unlock than a padlock on a mechanical valve located in the bowels of the boat.

Foggy

[Hudson Force]

Originally Posted by foggysail

I took the easy way out that I believe satisfies all requirements ............. a key switch for the electrical power is far easier to lock and unlock than a padlock on a mechanical valve located in the bowels of the boat.

Foggy

Has your system been USCG approved or passed an inspection? It's simple and obvious to all that an electrical circuit can have many switches. You may have an honorable intent, but I would be surprised if it was approved. Take care and joy, Aythya crew

[Captain Bill]

I was on a friend's recenly built powerboat last week. His overboard pumpout has no locking mechanism on the thru hull but does have a key lock controlling power to the macerator. Since his boat was built by a major manufacturer I would assume that it has been USCG approved.

[foggysail]

Originally Posted by CaptForce

Has your system been USCG approved or passed an inspection? It's simple and obvious to all that an electrical circuit can have many switches. You may have an honorable intent, but I would be surprised if it was approved. Take care and joy, Aythya crew

My boat has passed the CGAux inspections for the last two years. No problems with the key protection.

[marshmat]

Grunzster, I'd think your setup should be OK as long as there is some provision to physically lock the discharge through-hull in the closed position. The padlock you describe ought to suffice.
If I were building new, I'd probably follow CaptainForce's setup pretty closely, possibly with the addition of a valve between the tank and tee (in case the macerator requires servicing).
It's interesting to hear that the key-lock macerator switch is considered OK. The real test, of course, is when you're boarded by the CG or police; the Auxiliary have good intentions but they aren't lawyers or police.
Actually disconnecting the through-hull hose makes no sense from an environmental protection or an engineering standpoint; I'd be curious to see where in the legal code this is specified.

[Watercolor]

Grunzster,

Here's some food for thought.

1. In addition to your point, "Maybe shorter lifespan before the hoses start to stink, and needing more frequent cleanings from always having waste water in them." You might add, the problem of liming to your current concerns. Liming loves to form when waste (urine) and salt water are stagnant.

2. Why have the whole run of hose from tank to discharge as a potential source of smells and liming? I'm assuming that you have a macerator pump. I would recommend that ("if possible") your tank output hose go directly up to a point just above the tank at that point install your y or y-valve, then (again "if possible") up to the deck fitting and down to the macerator and discharge valve. Avoid any dips (again "if possible"). This does a couple things that may be helpful.

a. When you use the deck fitting for pump out nothing should remain in the line and a fresh water flush will help keep liming at bay. Any residual material in the hose should return to the tank.

b. If you're pumping overboard the same applies, except for what little remains in the tank, your lines should be clear.

c. Can you imagine trying to clear a limed hose with 30 gallons of waste backed up behind it? I have encountered liming only once, luckily I had a device that allowed me to easily disconnect the hose above the tank and encountered a minimum (a cup full) of waste escaping. My problem was that I had not fully followed my rule and routed the tank output hose so that it had a slight dip just after the tank. This was the easiest and simplest route at the time, I thought. I rerouted the hose to run out of the tank and directly up. I never again had the problem.

c. Lastly, the one big advantage of a y-valve is that it allows you to shut off the tank from the rest of the system. A broken macerator with a full tank of waste bearing down on it is no fun to remove. With a y-valve the most waste you have to deal with is whatever is in the hose.

I recommend that you don't use nylon fittings (that includes Marelon which is simply Dupont Zytel 13% glass filled nylon; nylon absorbs a lot of moisture and is a good source of waste system smells.

Aren't waste water systems fun. Hope this helps.

[off-the-grid]

Originally Posted by marshmat

If I were building new, I'd probably follow CaptainForce's setup pretty closely, possibly with the addition of a valve between the tank and tee (in case the macerator requires servicing).

Actually it does need servicing, but I'm just going to remove it instead. My tank is high enough, and above the waterline, so gravity drain will be no problem.

On the other hand after reading watercolor's response, I think I'll throw a new Y in at the same time. I can't route it exactly as you're describing, though. My tank is on a shelf above and behind the head, with really limited access of course. But the run of hose from my tank to the Y valve will only be about 1', though. I may be able to get it even a little shorter, will just make the valve a little harder to reach.

Based on some of these other posts I'm wondering, do I even need the pad lock, if the access panel behind the head is screwed in? You still have limited access to the thru-hull, but it will pretty much be impossible to reach the y valve with it in place. So, do screws count as a lock?

[off-the-grid]

I've decided to go with the diverter.
Since mine is technically acting as an on/off, not a diverter, I need to plug one of the outlets.

Any recommendations? Seems I can use about 3 different fittings and some hose to do this.

Or I was thinking, maybe to save a few $ and avoid have a giant unused pipe sticking out of it, why not just plug that port with some epoxy?

[rebel heart]

Not to derail the thread, but hopefully in the next few months I'll be ordering and installing one of the naturesheads composting heads. No lines, no smell, no nada. I'm praying that I finally turn the page on marine sanitation and get out of this game.

[off-the-grid]

I LOVE the idea of the Nature's Head, and seriously considered one. So many pluses. 2 less below the water thru-hulls, no holding tank. I can glass that spot in and gain a little extra storage. No more stinky pipes to clean.

But I seem to remember a few threads where people said it was great for short cruises, but just doesn't have the capacity for a full time live aboard.