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

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

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.

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.

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.

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.

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 ?

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 ?