Shower drain plumbing design
 

Where could I find some good insight into designing the plumbing to get
water out of my shower drain to an underwater thru-hull, and staying
out of the shower? The plumbing in my Beneteau allows some water to
come back into the shower drain at the base of my head, enough that
when I heal the boat, it coats the bottom of the head floor.

Seems after the pump stops, the extra water in the hoses to the pump
slowly let out water, maybe only 4-6 ounces, but enough to fill the
bottom and come up a small amount above the drain.

I suspect its designed poorly and I could upgrade it myself. I noticed
for example the diaphram pump wasn't design to be connected to
underwater thru-hulls.

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

Dan

Shower drain plumbing design
 

b393capt wrote:

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

I THINK there's a simple solution to your problem: pump longer.

The water that's running back into the sump is the water that's left in
the line between the sump and the top of the loop. Pumping longer should
move it over the top of the loop. If it doesn't--if dropping the water
level in the sump causes the pump to suck air that breaks its prime--a
one-way valve in the line just above the top of the sump may solve that
problems.

The thru-hull should always be closed except when actually dumping the
sump.

Btw...why would there be a filter in a sump drain line? Or do you mean a
strainer to trap hair etc?

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

Shower drain plumbing design
 

Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Yes, your right, I did mean a strainer rather than a filter. Says
Jabsco on the outside and is maybe 3 inches wide and round.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so? I was thinking it
won't work because the seal isn't very good on these things, and any
hair in the line will just make it worse.

Dan

p.s. Your book was great !

Peggie Hall wrote:
b393capt wrote:

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

I THINK there's a simple solution to your problem: pump longer.

The water that's running back into the sump is the water that's left in
the line between the sump and the top of the loop. Pumping longer should
move it over the top of the loop. If it doesn't--if dropping the water
level in the sump causes the pump to suck air that breaks its prime--a
one-way valve in the line just above the top of the sump may solve that
problems.

The thru-hull should always be closed except when actually dumping the
sump.

Btw...why would there be a filter in a sump drain line? Or do you mean a
strainer to trap hair etc?

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

Shower drain plumbing design
 

On 16 Nov 2006 20:05:38 -0800, "b393capt"
wrote:

Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Yes, your right, I did mean a strainer rather than a filter. Says
Jabsco on the outside and is maybe 3 inches wide and round.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so? I was thinking it
won't work because the seal isn't very good on these things, and any
hair in the line will just make it worse.

Hi,

Is there space for a/the filter after the sump?

cheers,
Pete.

Shower drain plumbing design
 

Is there apec for the shower to drain into a small sump tank and the
pump empties the sump tank - float switch in the tank switches it on.
Any water running back will merely go into the sump tank. Attwood and
Jabsco make small ones, or a plastic sandwich box can be adapted.

Shower drain plumbing design
 

Is there space for the shower to drain into a small sump tank and the
pump empties the sump tank - float switch in the tank switches it on.
Any water running back will merely go into the sump tank. Attwood and
Jabsco make small ones, or a plastic sandwich box can be adapted.

Shower drain plumbing design
 

Is there space for the shower to drain into a small sump tank?? The
pump then empties the sump tank - float switch in the tank switches it
on. Any water running back will merely go into the sump tank. Attwood
and Jabsco make small ones, or a plastic sandwich box can be adapted.

Shower drain plumbing design
 

Dan,
If you have the room (Hull depth), the correct answer is to drain into a
grey water sump tank using a conventional water trap. The grey water tank
accepts all waste water from the showers and the sinks on board. The sump
tank has a float control where the pump turns on at the high level and off
at the low level. These levels should be adjustable. The output line should
also have an anti siphon valve attached. This arrangment in some cases saves
room and also saves unecessary tru hulls. It is also impervious to heel. An
additional input should be provided for salt water flushing.
Steve

"b393capt" wrote in message
oups.com...
Where could I find some good insight into designing the plumbing to get
water out of my shower drain to an underwater thru-hull, and staying
out of the shower? The plumbing in my Beneteau allows some water to
come back into the shower drain at the base of my head, enough that
when I heal the boat, it coats the bottom of the head floor.

Seems after the pump stops, the extra water in the hoses to the pump
slowly let out water, maybe only 4-6 ounces, but enough to fill the
bottom and come up a small amount above the drain.

I suspect its designed poorly and I could upgrade it myself. I noticed
for example the diaphram pump wasn't design to be connected to
underwater thru-hulls.

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

Dan

Shower drain plumbing design
 

b393capt wrote:
Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Weeelll...it was an idea.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so?

My thought was, it would allow the pump to retain prime long enough to
pump the rest of the water out the line...but it would also prob'ly get
clogged up, so it wasn't the best idea I ever had.

p.s. Your book was great !

Thanks!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

Shower drain plumbing design
 

b393capt wrote:

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Use a manual diaphragm pump such as a Whale 10.

It does not require full prime to operate.

Lew

Shower drain plumbing design
 

Is there some best practices guide in boat building for designing the
plumbing for a shower drain ?

Shower drain plumbing design
 

b393capt wrote:
Is there some best practices guide in boat building for designing the
plumbing for a shower drain ?
\
Maybe installing a couple of joker valves would help, they are better
than the flapper ones. Admittedly they might eventially fail with hair
and other debri, thats why two. I don't think you have enough room
under the shower to install a sump, which is the answer. You never
empty a bilge pump line unless you are pumping downhill. Yes under way
close the thruhull.
Good luck.
"There is nothing - absolutely nothing - half so much worth doing
as simply messing about in boats." -- Kenneth Grahame
www.densnet.com

Shower drain plumbing design
 

I built a 39 foot FG sailboat about 20 years ago. The shower drain
plumbing (almost) never gave me a problem. Let me describe it.
Perhaps you can fit your boat similarly.

The shower (and two sinks) drained by gravity into a 6 gallon sump tank
located in the bilge below all drains. The sump was emptied by a small
pump. The pump discharge hose was lead up to form an anit-siphon loop
well above the (heeled) water line then over board via a sea cock that
was located in the center of the stern above the waterline. Being on
the center the exit was (almost) always above the water even when
heeled. The anti-siphon break in the loop is needed to prevent
possible back siphoning into the sump tank. Of course, when the pump
emptied the tank it cavitated and the pump was shut down by a manual
switch. Water would then drain from the loop and return harmlessly to
the sump tank. Voila!

Hair is always a problem with pumps. My wife and I were careful after
showering to wipe hair from the strainer and dump in the garbage (in
port) or into the head (at sea). Periodically (like every three months
while living aboard), the pump would have to be removed from the sump
tank and de-haired --- yuck!

BTW this scheme allowed me to have only three thru-hulls below the
waterline: engine input, head input, and head output.

Shower drain plumbing design
 

Fred,

It's not possible to do that in my production Beneteau, no room below
the grade of my shower bottom to put such a tank.

In desperation, not having any other ideas to work from or any
recommended designs that don't involve a sump, I am thinking of
replacing the Jabsco shower pump with a Gulper 220, and eliminating the
pump guard.

My hope is that
(1) The Gulper 200 will be more succesful at getting the liquid out
before the suction prime is broken, and less water will flow back into
the shower.
(2) Eliminating the pump guard and shortening the hose 10%, will reduce
the volume of fluid that can reside in the system, and flow back to the
shower. I believe the pump guard can be eliminated because the Gulper
220 materials specifically mention that it isn't needed.

Does anybody see any foley in doing this ?

Dan


wrote:
I built a 39 foot FG sailboat about 20 years ago. The shower drain
plumbing (almost) never gave me a problem. Let me describe it.
Perhaps you can fit your boat similarly.

The shower (and two sinks) drained by gravity into a 6 gallon sump tank
located in the bilge below all drains. The sump was emptied by a small
pump. The pump discharge hose was lead up to form an anit-siphon loop
well above the (heeled) water line then over board via a sea cock that
was located in the center of the stern above the waterline. Being on
the center the exit was (almost) always above the water even when
heeled. The anti-siphon break in the loop is needed to prevent
possible back siphoning into the sump tank. Of course, when the pump
emptied the tank it cavitated and the pump was shut down by a manual
switch. Water would then drain from the loop and return harmlessly to
the sump tank. Voila!

Hair is always a problem with pumps. My wife and I were careful after
showering to wipe hair from the strainer and dump in the garbage (in
port) or into the head (at sea). Periodically (like every three months
while living aboard), the pump would have to be removed from the sump
tank and de-haired --- yuck!

BTW this scheme allowed me to have only three thru-hulls below the
waterline: engine input, head input, and head output.

Shower drain plumbing design
 

On 14 Dec 2006 09:10:48 -0800, "b393capt"
wrote:

Fred,

It's not possible to do that in my production Beneteau, no room below
the grade of my shower bottom to put such a tank.

In desperation, not having any other ideas to work from or any
recommended designs that don't involve a sump, I am thinking of
replacing the Jabsco shower pump with a Gulper 220, and eliminating the
pump guard.

My hope is that
(1) The Gulper 200 will be more succesful at getting the liquid out
before the suction prime is broken, and less water will flow back into
the shower.
(2) Eliminating the pump guard and shortening the hose 10%, will reduce
the volume of fluid that can reside in the system, and flow back to the
shower. I believe the pump guard can be eliminated because the Gulper
220 materials specifically mention that it isn't needed.

Does anybody see any foley in doing this ?


A washing machine plumbing out kit comes with a non return valve,
maybe this could be used near the shower to prevent back flow. Eg:

http://www.toolstation.com/search.html?searchstr=51805
http://www.toolstation.com/images/library/stock/webbig/51805.jpg

OR,

Use a non return valve or ball valve further up, but loop the hose
from the shower drain down, before it comes up.

As long as the outlet is shut off 100%, and there is a 'U' bend at the
bottom of the hose, there is no way air can get in to break the vacuum
and let the water back down.

I suspect the hose from the shower drain is not looped down in this
way and/or there is a small air leak.

HTH,
Pete.

Shower drain plumbing design
 

Pete C:

Loop Down - The line does make a loop up to the sink and back down to
the pump and thru-full as an anti-siphon. When you are talking about a
loop down, you mean in addition too, right? E.g. come out of the
shower, loop down, then loop up. If that is what you mean, do I have
to loop down lower than the depth of my shower drain (I cannot, drain
is at lowest point on the boat), or can I get the same if I angle up,
then loop down, then continue up to the sink and back down to the pump
?

Non Return Valve - Thought of that. Other Beneteau owners have tried
the non-return valve, and found that it was useless after some hair
gets in it.




Pete C wrote:
On 14 Dec 2006 09:10:48 -0800, "b393capt"
wrote:

Fred,

It's not possible to do that in my production Beneteau, no room below
the grade of my shower bottom to put such a tank.

In desperation, not having any other ideas to work from or any
recommended designs that don't involve a sump, I am thinking of
replacing the Jabsco shower pump with a Gulper 220, and eliminating the
pump guard.

My hope is that
(1) The Gulper 200 will be more succesful at getting the liquid out
before the suction prime is broken, and less water will flow back into
the shower.
(2) Eliminating the pump guard and shortening the hose 10%, will reduce
the volume of fluid that can reside in the system, and flow back to the
shower. I believe the pump guard can be eliminated because the Gulper
220 materials specifically mention that it isn't needed.

Does anybody see any foley in doing this ?


A washing machine plumbing out kit comes with a non return valve,
maybe this could be used near the shower to prevent back flow. Eg:

http://www.toolstation.com/search.html?searchstr=51805
http://www.toolstation.com/images/library/stock/webbig/51805.jpg

OR,

Use a non return valve or ball valve further up, but loop the hose
from the shower drain down, before it comes up.

As long as the outlet is shut off 100%, and there is a 'U' bend at the
bottom of the hose, there is no way air can get in to break the vacuum
and let the water back down.

I suspect the hose from the shower drain is not looped down in this
way and/or there is a small air leak.

HTH,
Pete.

Shower drain plumbing design
 

I am thinking of the following solution, any comments ?

1. Replace the Jabsco Diaphram pump with a Whale Gulper. I believe this
will have two benefits, allow me to eliminate the Pump Guard (Whale
advertises that a pump guard is not needed in a shower application, the
pump can deal directly with the soap & hair), and I hope it's so much
better than the Jabsco that it pulls more of the water out of the boat
before it looses suction.

2. Either eliminate Pump Guard entirely (to get a better vacumm). If
people don't recommend I do that, then maybe I will turn it so that the
water inlet is on top and exit is on bottom, such that I eliminate it
contributing to the water flow back into the shower.

3. Shorten up the lines. They seem longer than then need to be, for
example eliminate the two feet of line running along the floor before
rising up to form the loop. Hoping shorter length may have less
opportunity to store water that can return to shower. This change I am
most aprehensive about ... as the that two length of hose might be
providing a positive benefit, being that it is at or below the level of
the drain and might be helping to increase the capacity of the drain.

4. Or, instead of shortening the lines, I might first create a ramp up,
then loop down per Pete C.s suggestion.

Any thoughts ?

Shower drain plumbing design
 

Any comments ?


b393capt wrote:
I am thinking of the following solution, any comments ?

1. Replace the Jabsco Diaphram pump with a Whale Gulper. I believe this
will have two benefits, allow me to eliminate the Pump Guard (Whale
advertises that a pump guard is not needed in a shower application, the
pump can deal directly with the soap & hair), and I hope it's so much
better than the Jabsco that it pulls more of the water out of the boat
before it looses suction.

2. Either eliminate Pump Guard entirely (to get a better vacumm). If
people don't recommend I do that, then maybe I will turn it so that the
water inlet is on top and exit is on bottom, such that I eliminate it
contributing to the water flow back into the shower.

3. Shorten up the lines. They seem longer than then need to be, for
example eliminate the two feet of line running along the floor before
rising up to form the loop. Hoping shorter length may have less
opportunity to store water that can return to shower. This change I am
most aprehensive about ... as the that two length of hose might be
providing a positive benefit, being that it is at or below the level of
the drain and might be helping to increase the capacity of the drain.

4. Or, instead of shortening the lines, I might first create a ramp up,
then loop down per Pete C.s suggestion.

Any thoughts ?