Heads plumbing arrangement, sanity check please.

R

R.Ems

Well-Known Member
Joined
1 Apr 2022
Messages
354
Visit site
I am re-installing my Blakes toilet, and I want to be able to flush it with bilgewater as well as sea water, killing two birds with one stone.
I plan to use a two way valve, as sold by ASAP etc.
A couple of people have raised concerns about flooding the bilges somehow. But in my design, I don't see how that could happen.

1) Water can only flow one way or the other way, through the two way valve.
2)The anti-syphon loop should prevent flooding.
3) The seacock is only open while using the heads.

Am I missing something obvious? I will try and upload a sketch. Thanks for expert opinions.52B2C8B8-47BA-47E1-9027-B2D647E5AD7A.jpeg
 
ash2020 said:
How much bilge water do you build up between visits to the heads? Is the boat sinking?
Click to expand...
Not sinking but wooden... Between heads visits, negligible. Over time, in periods of heavy rain, inches. It comes down the mast, and the heads is over the mast step.
 
R.Ems said:
I am re-installing my Blakes toilet, and I want to be able to flush it with bilgewater as well as sea water, killing two birds with one stone.
I plan to use a two way valve, as sold by ASAP etc.
A couple of people have raised concerns about flooding the bilges somehow. But in my design, I don't see how that could happen.
1) Water can only flow one way or the other way, through the two way valve.
2)The anti-syphon loop should prevent flooding.
3) The seacock is only open while using the heads.
Am I missing something obvious? I will try and upload a sketch. Thanks for expert opinions.
Click to expand...

I don't think there is any risk of flooding with a vented anti-syphon loop and a two way valve which cannot connect the outlet pipe to the bilge suction pipe

BUT

The anti-syphon valve will let air in when you try to flush with seawater. You will find flushing very inefficient.
Maybe a little air bleed like they fit in the inlet loop of Lavacs will be a better idea.

1649164925426.png

Your scheme does not allow for directly pumping out the bliges. Do you have another dedicated bilge pump?
 
Last edited:
VicS said:
I don't think there is any risk of flooding with a vented anti-syphon loop and a two way valve which cannot connect the outlet pipe to the bilge suction hose

BUT

The anti-syphon valve will let air in when you try to flush with seawater. You will find flushing very inefficient.
Maybe a little air bleed like they fit in the inlet loop of Lavacs will be a better idea.
Click to expand...
Good point! Cheers for that! I could get round it by adding a pump between the seacock and the anti syphon loop.
 
R.Ems said:
Good point! Cheers for that! I could get round it by adding a pump between the seacock and the anti syphon loop.
Click to expand...
Two pumps plus a discharge t pump is getting too complicated

Must go... appt at Docs

Think about it later
 
Also, my expeeience with two way valves makes me inclined to suggest fitting a separate valve on each inlet pipe and just open the one you want to draw water from.
 
That does not make sense if it is a Blakes Lavac. You do not have a pump in the inlet. Look at the diagram in Vics post. The little "valve" which is actually a Bic pen plug with a hole in t is to relieve the vacuum after the loo has been used. The bowl is refilled by the vacuum you create when pumping out.

Having said that, there is no reason why you cannot fit a Y valve in the inlet pipe after the inlet seacock so that you can suck from the bilge. You will be able to pump using the outlet pump as long as the vacuum created by the seal on the bowl holds.
 
SlowlyButSurely said:
If that's the case the pump will be pumping sewage into the bilge. That can't be right?
Click to expand...
The Blakes has a different pump for discharging the bowl contents through a seperate seacock. This is just about putting seawater into the bowl. (And hopefully bilgewater as well.)
 
I would have a valve on the bilge suction line & one on the sea cock. Then whichever you wanted to use is the one you open. However, with those valves are you happy that a visitor would not make a mistake.
Personally I cannot see the point & would just hook a proper pump to the bilge & pump it out, thus bye passing the heads. The benefit of fresh water to the heads can be solved by tipping some in the bowl if it is that important to you.
But i would also take time out to sort the leaks. Just because it is a wooden boat is no excuse for it to leak.
 
Daydream believer said:
I would have a valve on the bilge suction line & one on the sea cock. Then whichever you wanted to use is the one you open. However, with those valves are you happy that a visitor would not make a mistake.
Personally I cannot see the point & would just hook a proper pump to the bilge & pump it out, thus bye passing the heads. The benefit of fresh water to the heads can be solved by tipping some in the bowl if it is that important to you.
But i would also take time out to sort the leaks. Just because it is a wooden boat is no excuse for it to leak.
Click to expand...
The valves, whether two way or individual ones, would normally be switched to seawater flushing, the crew would not be needing to touch them.
The bilge in question is amidships and I don't want to make a hole in the topsides for occasional bilge pumping.
You are quite right, I have no excuse that my mast skirt leaks a bit in heavy rain .
 
Daydream believer said:
I would have a valve on the bilge suction line & one on the sea cock. Then whichever you wanted to use is the one you open. However, with those valves are you happy that a visitor would not make a mistake.
Personally I cannot see the point & would just hook a proper pump to the bilge & pump it out, thus bye passing the heads. The benefit of fresh water to the heads can be solved by tipping some in the bowl if it is that important to you.
But i would also take time out to sort the leaks. Just because it is a wooden boat is no excuse for it to leak.
Click to expand...
The valves, whether two way or individua
The bilge in question is amidships and I don't want to make a hole in the topsides for occasional bilge pumping.
You are quite right, there is no excuse whatsover for heavy rain leaking through the mast skirt.
 
You must log in or register to reply here.

Share this page

Top