Should I keep the Thru Hull Discharge?

[Dave_E]

Hi All,

As I mentioned in previous posts, I am replacing the 1970's vintage Type 1 holding tank and plumbing with a holding tank and pump out. My question is should I retain the Y valve plumbing, knowing that I legally cannot dump anywhere I'll ever be with this trawler? Why?

Dave

 

[Bay Pelican]

I am confused as to whether you are proposing getting rid of the Y valve so you have a straight shot to the holding tank leaving the thru hull in place but capped off, or getting rid of both the Y valve and the thru hull.

Getting rid of the Y valve is probably a good idea. Less complication is my motto. Getting rid of the thru has is more complicated. You would be spending money to get rid of a good thru hull that would not be a problem if just capped off. In addition you cannot predict the future. You may need that thru hull for something else, including as an emergency discharge when your pump out system fails.

 

[Shrew]

I would leave the Y valve in place. I don't like a through hull with a capped hose. I'd rather remove it and glass the hole back in. However, that is a cost to continue not using something you're already not using. Plus, down the road the next owner might want the option.

Leave it as is and turn the Y valve to holding tank. It will continue working exactly the way you want it to.

 

[Nomad Willy]

Keep the valve and overboard pluming.
Ya just don't know when you may need to discharge the contents of the holding tank. Options are usually good.
Remove the through hull now and then, inspect and check for function. Now and then could be 2 yrs, 10 years or other.
This does not apply to ball valves but if you have a tapered rotary valve it may need to be laped. Especially if it's leaking. If you put abrasive on the tapered valve/rod, exercise it some and the rod should become "bright" all along it's contact length. If not lap more.

 

[Dave_E]

I am confused as to whether you are proposing getting rid of the Y valve so you have a straight shot to the holding tank leaving the thru hull in place but capped off, or getting rid of both the Y valve and the thru hull.

Getting rid of the Y valve is probably a good idea. Less complication is my motto. Getting rid of the thru has is more complicated. You would be spending money to get rid of a good thru hull that would not be a problem if just capped off. In addition you cannot predict the future. You may need that thru hull for something else, including as an emergency discharge when your pump out system fails.

Good call, I should have been more clear. Of course the thru hull will stay, closed and capped off.

 

[S41]

When I replace the entire sewer system on my boat, I removed the Y valves on both heads and capped the through hull fittings above the water line of the boat. Each head is now plumbed directly to the holding tank. I have an overboard pump to empty the tank if I am in an area where it is allowed.

It was an easier job to just get rid of the Y valves. They both needed replacing (one leaked and the other was frozen) as did the hose to the through hull fittings. On my vessel, this was, in my opinion, a good solution and has worked very well for the past two years.

 

[Larry M]

I'd keep the y valve. When doing head maintenance or troubling shooting leaks, I've more than once switched the valve to direct discharge. We had a serious leak on our VacuFlush on Christmas Eve a couple of years ago. It took probably 20 flushes to figure out what it was and verify the problem was fixed. The holding tank would have been full before we could have had a pump out. Other than that, the handle is off once in the right position except for periodically exercising the valve.

 

[tiltrider1]

For a boat operating in The PNW, I recommend removing the Y valve and capping the thru hull fittings. This assumes your holding tank has its own discharge thru hull. Along with removing the Y valve, you can remove the antisiphon and extra hose.

I haven't had a Y valve on any of my boats for the last 20 years.

 

[hfoster]

I would leave the Y valve in place. I don't like a through hull with a capped hose. I'd rather remove it and glass the hole back in. However, that is a cost to continue not using something you're already not using. Plus, down the road the next owner might want the option.

Leave it as is and turn the Y valve to holding tank. It will continue working exactly the way you want it to.

+1

Cheers.

H.

 

[koliver]

Exercise the Y valve or it will seize in position. That may not be a problem if you never want to turn it to the other side of the Y, but some next owner may have trouble during purchase if it won't move.

 

[caltexflanc]

Some good advice here on advantages of keeping it, one other consideration: are you absolutely positive you will never sell the boat, let alone never take it out of a no raw sewage discharge area?

 

[Chrisjs]

If you do not exercise the Y-valve on a fairly regular basis (weekly), dried crud (for want of a better word) in the valve will set like cement. Then you will need to disassemble the valve, clean and re-assemble. Also, good idea to keep it (the Y valve) lubricated with vaseline. I would keep the Y-valve. You never know when you might have the opportunity or desperate need to pump out to sea. But since you are apparently concerned about the "unused" thruhull, it would be a good idea to make sure that all fittings / hoses are in good condition and well clamped, and that your Y-valve is actually above water level.

 

[tiltrider1]

Dave_E is only giving up direct discharge. He can still discharge his holding tank in certain areas. Why would he even bother to turn the Y valve for that one flush he just happened to be transiting through. He would be much more concerned with dumping his holding tank while he had the chance. In the PNW he is never going to be anchored in a place that allows direct discharge.

The only case for leaving the Y valve in was for an unlikely possible repair maybe some time in the future. More likely the day he goes to sell the boat the Y valve will be frozen and the surveyor will require it repaired.

Even when I transit 25 miles off the coast I use the holding tank and dump it when needed.