45581RE: Macerator Pump Installation
- Nov 23 9:31 PM
We sailed a charter boat that had a simple system. The head pumped directly to the holding tank. No Y valve. From the holding tank there were two outlets, one to the deck fitting for shore side pump out and another for pump out through the 1.5" through hull. There was a whale gulper type pump and, I think, a macerator in the line before the through hull. If shore side pump out facilities were not available, we were advised to wait till we were three miles off shore, then open the through hull and turn on the pump/macerator switch until the tank was empty.
Worked great and if I were to re plumb I'd use that approach.
---In firstname.lastname@example.org, <jim@...> wrote:The holding tank is being replaced, so all options are open.
But why do I need a Y-valve between the holding tank and macerator pump? If the deck fitting is tight, the pump will draw only from the holding tank. Conversely, a pump out through the deck fitting should be able to pump through the macerator pump and can draw only from the holding tank (or so is my working theory). If there is reverse leakage through the macerator pump, a simple shut off value will suffice.
Given my cruising area, I expect to rarely, if ever, have the tank pumped commercially. That being the case, I'd like the minimize the number things to be set (or set incorrectly) when changing the configuration. A Y-valve upstream from the macerator pump, for example, will damage the macerator pump if left in the wrong position causing the pump to run dry. A Y-valve down stream from the macerator pump in the wrong position can have consequences I don't want to even think about.
But two discharge connections to the holding tank sounds like a good idea. The down side is???
On 11/23/2013 1:22 PM, navip11@... wrote:
Depending upon how your current plumbing is run, you will need a Y-valve on the discharge line from the holding tank to go to either A. Deck Pump out or B. macerator. Ideally, your holding tank may have the option of adding an additional discharge line which is what we ended up doing. Depending upon how old the waste lines are, you might end replacing those in the process. We did.
---In email@example.com, <jim@...> wrote:
I've got Peggy's book on order, but I'd like the benefits of any thoughts and/or wisdom on the subject of macerator pumps and installation thereof. I'm in the process of designing an upgrade from a pro-forma mostly legal system to one that is potentially useable. The question at hand is how many Y-valves are actually required and where they should be located. Obviously there is at least one down stream from the head directing, er, effluent to either the though-hull or the holding tank. The two real questions are:
- Does there need to be a Y-valve (or even a simple one way valve) between the holding tank and the macerator pump so the deck pump-out will continue to work? It seems to me that backflow through the macerator pump should be minimal, if any, so no valve should be necessary.
- Does there need to be a Y-valve in the through-hull discharge line to prevent backflow into the head when the macerator pump is running, or is the joker valve in the head sufficient to prevent this?
A simple shutoff valve between the holding tank and macerator pump does seem like a prudent precaution to allow the pump to be removed if it failed or needed to be serviced. A Y-valve seems overkill.
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