Is it possible/advisable to put a valve near the holding tank on the overboard discharge hose. The design of my system allows tank contents to fill the hose from the tank to the overboard discharge through hull valve. I believe this hose is fully permitted and thus causing holding tank odor in the boat. I was thinking of installing a second valve in the immediate area of the tank discharge port to prevent this in the future. Any thoughts?
Holding tank discharge hose question
- Thread starter ScottRPh
- Start date
Welcome to the site @ScottRPh .
You may be able to empty the hose and subsequently fill with air if you close the first valve at the tank immediately after the macerator has pumped out all of the tank contents and start sucking air. However, you will still be stuck with a film of
inside the hose unless you can flush it with fresh water to clean it out. Without rinsing with fresh water, you haven't accomplished anything.
This is just way too much trouble and hassle to try to save this short length of hose when you can just plan on replacing it every 10 years or so at the same time you change the hose which leads from the head to the holding tank.
That 10 years before permeation is based on a top notch hose like Raritan/Saniflex Odor Shield Marine Hose or Trident Sani Shield Sanitation Hose.
Not entirely clear here. I can picture your wanting to install the first valve at the tank outlet.
This valve I can't picture unless it is right at the thru-hull ? What happened to the macerator pump in between ?
You may be able to empty the hose and subsequently fill with air if you close the first valve at the tank immediately after the macerator has pumped out all of the tank contents and start sucking air. However, you will still be stuck with a film of
inside the hose unless you can flush it with fresh water to clean it out. Without rinsing with fresh water, you haven't accomplished anything.This is just way too much trouble and hassle to try to save this short length of hose when you can just plan on replacing it every 10 years or so at the same time you change the hose which leads from the head to the holding tank.
That 10 years before permeation is based on a top notch hose like Raritan/Saniflex Odor Shield Marine Hose or Trident Sani Shield Sanitation Hose.
The overboard discharge hose leads directly to the discharge thru hull. No macerated pump in the line. The holding tanks is about 4 feet above the discharge valve, so gravity discharge from the holding tank.
Yes, that may be the way to go. I am thinking increasing the size and design of my system, this the question.Welcome to the site @ScottRPh .
Not entirely clear here. I can picture your wanting to install the first valve at the tank outlet.
This valve I can't picture unless it is right at the thru-hull ? What happened to the macerator pump in between ?
You may be able to empty the hose and subsequently fill with air if you close the first valve at the tank immediately after the macerator has pumped out all of the tank contents and start sucking air. However, you will still be stuck with a film of
This is just way too much trouble and hassle to try to save this short length of hose when you can just plan on replacing it every 10 years or so at the same time you change the hose which leads from the head to the holding tank.
That 10 years before permeation is based on a top notch hose like Raritan/Saniflex Odor Shield Marine Hose or Trident Sani Shield Sanitation Hose.
Wow. Now THAT saves the price of replacing the macerator pump every so often.
I still feel it's not worth all the effort unless you can rinse the discharge hose with clean water before isolating.
I see you're in the process of currently increasing the design and size of your head system, so maybe go the limit and install a flushing system which should increase the years 'til permeation of the new hoses.
Here is my system after changing from a Jabsco To a Raritan PH ll Superflush.
The red valve has the option of sucking potable water straight from the sink while the sea-water suction is closed and clears the head discharge line of sewage and seawater organisms. All this courtesy of a delightful young lady by the name of @Peggie Hall HeadMistress who is our resident sewage treatment specialist.
If you really want to go hog-wild for something to build during the cold winter months, you could even lead the fresh water discharge from the head pump to your drain lines and maybe even get a few extra years out of them. It might be something like operating a petroleum refinery when you visit the head with opening and closing of valves everywhere but as I said, it may give you a few extra years. Mind you, with the latest generation of sanitation hoses, probably not worth the effort to rinse your drain lines. Check the archives for info on the fresh water flushing system. Well worth it if you've already got the system in pieces.
I still feel it's not worth all the effort unless you can rinse the discharge hose with clean water before isolating.
I see you're in the process of currently increasing the design and size of your head system, so maybe go the limit and install a flushing system which should increase the years 'til permeation of the new hoses.
Here is my system after changing from a Jabsco To a Raritan PH ll Superflush.
The red valve has the option of sucking potable water straight from the sink while the sea-water suction is closed and clears the head discharge line of sewage and seawater organisms. All this courtesy of a delightful young lady by the name of @Peggie Hall HeadMistress who is our resident sewage treatment specialist.
If you really want to go hog-wild for something to build during the cold winter months, you could even lead the fresh water discharge from the head pump to your drain lines and maybe even get a few extra years out of them. It might be something like operating a petroleum refinery when you visit the head with opening and closing of valves everywhere but as I said, it may give you a few extra years. Mind you, with the latest generation of sanitation hoses, probably not worth the effort to rinse your drain lines. Check the archives for info on the fresh water flushing system. Well worth it if you've already got the system in pieces.
Ralph, thanks for the feedback. The current discharge hose looks like it has been on the boat for a while so maybe the is the simplest solution. I currently have a pressure fresh water system, so thinking may need to just get the system clean and healthy with the maintenance suggestions in Peggy’s book. Again thanks for the feedback.
To be a better steward of our waterways, why wouldn't you install a macerator? Now to your question.. I have sewage rated PVC gate valve on a close nipple at the holding tank outlet. The valve is connected to the macerator by means of a PVC sewage rated union. Should the macerator fail, the union can be opened and the pump easily removed while the gate valve holds the tank contents back.
Your prime reasons appear to be odor mitigation. The tank odors could be related to venting..Salt water is not your friend. The organisms that are in the salt water will greatly add to odor.. If you have multiple water tanks onboard, consider using one to provide flush water..
Your prime reasons appear to be odor mitigation. The tank odors could be related to venting..Salt water is not your friend. The organisms that are in the salt water will greatly add to odor.. If you have multiple water tanks onboard, consider using one to provide flush water..
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,143
The purpose of the valve at the thru hull is not to control the black water from the holding tank. It is to protect the boat by stopping the open water ( ocean or lake) from entering the boat.
The usual design is to have a Y valve on the line near the tank. It provides a path for the black water to exit the tank by a suck out fitting on the deck, or the thru hull fitting.
There would be no simple system to rig that would let you keep the hose clear between the tank and the thru hull. Out side water wants to get in through the thru hull or black water wants to drain out.
Get a premium hose as suggested by Ralph and change it as needed.
The usual design is to have a Y valve on the line near the tank. It provides a path for the black water to exit the tank by a suck out fitting on the deck, or the thru hull fitting.
There would be no simple system to rig that would let you keep the hose clear between the tank and the thru hull. Out side water wants to get in through the thru hull or black water wants to drain out.
Get a premium hose as suggested by Ralph and change it as needed.
Hey foljs. Website kicking my butt a bit. Anyway, have tank with pump out, macerator to overboard and straight overboard options. Valve is set to flush straight overboard (bahamas). Wife flushed and nasty stream of liquid flew out of vent. Any thoughts as to why or how to correct?? Should be bypassing the tank completely. Thanks in advance
Hi Scott. Our boat has a similar setup with a wye fitting connecting the tank discharge hose to either the deck pump out fitting or the overboard macerator pump. Whenever I use the overboard macerator pump I make it a practice to clean out the overboard hose with fresh water upon returning from a cruise.
You can replace the permeated hose if that is the odor source. Not sure if it is necessary to install a wye valve, instead just clean out the overboard hose with fresh water upon returning from a cruise. All I do is after pumping out the holding tank, I fill it with fresh water, then run the macerator overboard pump for a minute or so to make sure the hose is cleaned out, then finish pumping out the holding tank. I keep pouring fresh water through the tank vent scupper while continuing the pump out until clear water appears.
Halbe...I'm guessing you have two problems: 1. an overfull tank most likely caused by 2. a malfunctionin y-valve that's sending waste into the tank when it should be sending it overboard.
Scott RPh...Install an accessible shutoff valve in the tank o'board discharge line close to the tank. Keep it and the seacock on the thru-hull closed except when dumping the tank.
Ralph...Don't blame me for the over-complicated plumbing nightmare shown in your photo. It doesn't even begin to resemble anything I'd ever recommended doing.
--Peggie
Scott RPh...Install an accessible shutoff valve in the tank o'board discharge line close to the tank. Keep it and the seacock on the thru-hull closed except when dumping the tank.
Ralph...Don't blame me for the over-complicated plumbing nightmare shown in your photo. It doesn't even begin to resemble anything I'd ever recommended doing.
--Peggie
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Thanks Peggie. That is exactly what I intend to do. I’ll share my design for your insights next time we talk. Scott
You'll find that my design conforms to the best standards you will find in any petroleum refinery
.