Anchor washdown pump replacement


greatketch@...
 

Stephan,

I love the Water Puppy pumps and have used them for everything from shower sump pumps to bilge pumps, and it will be perfect for people who only use the original Amel installed outlet for the chain wash.  I think for your application, where you have a 3-way valve and hose for targeted spray, you might find something else better suited.

As good as the Water Puppies are, they are relatively low pressure, and will not work well pushing water through a spray nozzle on a hose.  And if that nozzle can shut off the water flow, the pump will have problems when deadheaded.

The problem with many of the other pressure pumps  sold for wash down service is that they are diaphragm pumps. When used below the waterline a tear or other failure of the diaphragm means lots of water can flood in very quickly.  That's one of the reasons you have found so many do not recommend installation below the waterline.

You might consider one of these of a size you consider suitable:

The only possible leak point is the shaft seal, which--even if it was to fail totally--will not allow water to flood in quickly.  They are self-priming, so if you wanted to move it to a level above the waterline it would be fairly easy to find a suitable spot because they are very small in foot print.

I have been using this style pump as my freshwater pressure pump for a year now without problems. That's probably more hours of operation than you'd ever accumulate in anchor wash down service!

Bill Kinney
SM160, Harmonie
Boston, Mass



svperegrinus@yahoo.com
 

Shurflo Pro Blaster II 4258-163-E09 24V 7 Amps Max 5 GPM 60 PSI

When we bought hull No. 350 five years ago, the factory wash down pump (located in the small starboard locker, adjacent to the deck shower) was dead, so we installed this.  Day-to-day, use the Gardena nozzle/pistol at the end of a spiral hose, and as the Shurflo has a pressure sensor, it shuts down when the pistol trigger is not pulled.

We make sure and turn off the toggle switch at the top of the locker, so when the wash down is not being used, there is no power to the pump (same as the anchor wash down).

The only question is if this pump would withstand constant saltwater use.  Ours runs fresh water 90% of the time, we switch it to saltwater only in the rare cases when the anchor wash down is insufficient and we need extra cleaning.

Cheerio,

Peregrinus
SM2K (2002)
at anchor, Kavala (Greece)


svperegrinus@yahoo.com
 

Oops, I meant to say the factory outlet and switch are in the starboard locker; the Shurflo itself is on the factory location, a port shelf outboard of the watermaker pre filters and above the anchor wash down pump.

Cheerio,


Paul Osterberg
 

Bill, 
I do not know enough about pumps. 
But why should a diaphragma pump have risk of flooding the boat if the diaphragma rupture if the pump house itself is intact? 
My two original saltwater pumps for the toilets looks very much as diaphragma pumps.

Paul on SY Kerpa SM#259


greatketch@...
 


I can not comment on the saltwater toilet pumps specifically, because my boat has manual toilets, but I am not aware of any diaphragm pumps that have a secondary seal backing the diaphragm.  The case might cover the diaphragm, but it is not usually designed to be water tight.  Again, there might be some that are that I do not know of.

I do not mean to suggest that you can never use a diaphragm pump below the waterline. It is not an unusual arrangement.  You just need to be aware that a relatively thin piece of flexible rubber is all that stands between the inside of your boat and the ocean.  With a well designed and built pump failure is not likely, especially if the diaphragm is replaced on a regular basis, but it is possible.  There are lots of places on our boats where keeping the water out requires attention.  This is just another.

It is certainly not the case that other types of pumps can never leak.  With the possible exception of magnetic drive seal-less pumps or more exotic "canned" pumps, any pump can leak.  The difference is that a diaphragm pump can leak a LOT, and a shaft seal pump can drip or dribble.

Bill Kinney
SM160, Harmonie
Boston, Mass



---In amelyachtowners@..., <osterberg.paul.l@...> wrote :

Bill, 
I do not know enough about pumps. 
But why should a diaphragma pump have risk of flooding the boat if the diaphragma rupture if the pump house itself is intact? 
My two original saltwater pumps for the toilets looks very much as diaphragma pumps.

Paul on SY Kerpa SM#259


Paul Osterberg
 

Thank you Bill
I will dig into this and learn more, I send a question to Jabsco about their pumps and placement below water line, If/When I get an answer I will post it.
The pumps you suggest looks solid, were do you buy them, the link was to the manufacturer and I tried to google but did not found were to buy, my internet is slow so did not made to many attempts to find a re seller
Paul on SY Kerpa SM#259 Block Island


greatketch@...
 


Paul Osterberg
 

Got answer from Jabsco today,
"There is the possibility of the pump leaking if the diaphragm fails but the hull fitting the pump is connected to should have a seacock which should be closed when the pump isn’t in operation."

So I will change to another pump, thank's for making me aware of the issue.
Paul on SY Kerpa SM259