Home Pumpout System

[Tedd]

Last year I bought a new house whose previous owners had thoughtfully installed an RV septic drain that's connected to the house's septic system. I finally got around to installing a pump-out system for the boat.
The system is based on a Bosworth "Guzzler" 500D hand pump with a "duckbill" valve. Apparently, the "duckbill" valve is critical when using the pump with holding tank effluent. I selected that pump some months ago and I've forgotten all the ins and outs of the choice but I'm happy with the performance. You can buy them on Amazon but I ordered mine through a dealer to be sure that I got the right valve.
It takes about ten minutes to empty my holding tank, which I think is 30 gallons.
[I thought I should add that the adapter I used for the holding tank port is a 1-1/2 inch cam-and-groove to 1-1/4 inch NPT. It took a while to figure out that the thread on the port is 1-1/4 NPT but I think that size is pretty standard, so I hope that information will be helpful to other sailors.]

 

[dlochner]

The Duckbill serves as check valve. If you don't have on on the in and out sides of the pump and oriented the correct way, it won't pump.

 

[Tedd]

Thanks, @dlochner . I should also point out that it has to be a "duckbill" valve, not the standard check valve that comes with most pumps of that kind. Solids in the effluent will block a standard check valve, according to Bosworth.

 

[Project_Mayhem]

Nice setup! I had one of those as a backup bilge pump. Careful not to over tighten the screws when you have to rebuild it. I'd look into which components are affected by UV to reduce the maintenance of your system overall

 

[Tedd]

Thanks, @Project_Mayhem . Good idea about the UV. I'm planning to make a shroud around the pump by adding an old piece of canopy that will hang from the hem of the main canopy. That'll keep UV (and leaves, rain, etc.) off the pump and fittings.

 

[dlochner]

Thanks, @Project_Mayhem . Good idea about the UV. I'm planning to make a shroud around the pump by adding an old piece of canopy that will hang from the hem of the main canopy. That'll keep UV (and leaves, rain, etc.) off the pump and fittings.

The most vulnerable part is the bellows on the pump.

 

[Tedd]

The most vulnerable part is the bellows on the pump.

Bug lands on diaphragm, crow pecks at bug...

 

[dlochner]

Bug lands on diaphragm, crow pecks at bug...

Maybe, however UV does much more damage to the bellows.

 

[Peggie Hall HeadMistress]

Might have been simpler to use a macerator pump.....

--Peggie

 

[Tedd]

Hi Peggie,

I did briefly consider using a macerator pump but it has some drawbacks.

• A macerator pump is about the double the cost of a hand pump.
• A macerator pump needs power, which would mean either connecting it to the boat or running a cord from the house to a 12 V power supply (plus related connectors, switches, etc.).
• A macerator pump would also have been more expensive and more difficult to maintain and repair than a hand pump. There's practically nothing to go wrong with a hand pump and what might need repair or replacement, such as the diaphragm or the check valves, can be done in minutes at very low cost.

So, the macerator would cost more and be more difficult to install and maintain while providing effectively no benefit over a hand pump, since I have no need for the macerating function.

Tedd

 

[Peggie Hall HeadMistress]

I missed that your pump is MANUAL, not electric.

--Peggie

 

[Project_Mayhem]

I forgot to mention that my vintage bilge hose liked to slide off of the pump inlet and outlet. Maybe a second hose clamp might help? Maybe my hose was stretched out?

 

[Tedd]

Hi @Project_Mayhem ,

Yes, the Guzzler pump I bought has completely smooth ports--no barbs or texture to help keep the hose in place. I'm not expecting any problems that way in my installation because gravity is helping flow on the outlet side so the clamp really only needs to be able to hold the weight of the hose plus drag from the effluent (which I expect is very small). On a bilge installation, the clamp has to also be able to hold the pressure in the outlet hose, which is going to be at least a few feet of head plus a bit more depending on how hard you're pumping.

Perhaps a bit of RTV or 3M 4000?

 

[dlochner]

I forgot to mention that my vintage bilge hose liked to slide off of the pump inlet and outlet. Maybe a second hose clamp might help? Maybe my hose was stretched out?

Hoses tend to dry out over time and become hard. When that happens it is not easy to get enough clamping pressure to stop leaks. Time for new hose. If there is sufficient room on the barb, a second clamp may help for a while.

 

[Peggie Hall HeadMistress]

Fwiw, ABYC standards call for double clamping all sanitation system hose connections. Screws should be 180 apart...at least 90 if access makes 180 impossible.

--Peggie

 

[Peggie Hall HeadMistress]

Perhaps a bit of RTV or 3M 4000?

In any other installation, I'd say "nope...never use sealant on sanitation hose connections." But because yours is a bit unique and doesn't impact the rest of the system, just be sure to use something that will let you remove the connection using heat to soften the "glue." And you really double clamp too.

--Peggie

 

[Project_Mayhem]

Hi @Project_Mayhem ,

Yes, the Guzzler pump I bought has completely smooth ports--no barbs or texture to help keep the hose in place. I'm not expecting any problems that way in my installation because gravity is helping flow on the outlet side so the clamp really only needs to be able to hold the weight of the hose plus drag from the effluent (which I expect is very small). On a bilge installation, the clamp has to also be able to hold the pressure in the outlet hose, which is going to be at least a few feet of head plus a bit more depending on how hard you're pumping.

Perhaps a bit of RTV or 3M 4000?

Mine had smooth ports as well. The vintage hose was like aquarium or bilge hose with a reinforced plastic spiral built in. It's grip on the port got worse over time. It looks like you bought some high quality sanitation hoses so hopefully it wont be an issue for you

 

[dlochner]

Mine had smooth ports as well. The vintage hose was like aquarium or bilge hose with a reinforced plastic spiral built in. It's grip on the port got worse over time. It looks like you bought some high quality sanitation hoses so hopefully it wont be an issue for you

The hose looks like Shields vinyl hose which @Tedd can confirm. I've used this a couple of times and regret it every time. It is difficult to work with and doesn't slide on to barbs, smooth or ridged easily. When heated it can become hard and even less cooperative. In an application like Ted's it will work because he has plenty of room to work in, on a boat with cramped quarters, forget it! Don't buy this crap even if it is cheaper.

The last time I used it was for a short run from the vented loop to the seacock. It went on partially using the usual methods involving a lot of foul language and would not come off. Eventually I heated some water and poured down the hose, that softened it enough for it to be removed.

The easiest hose to work with is Raritan Sani-Flex, little more expensive, but you'll save money on band-aids and ibuprofen, not to mention not offending small children with your language.

 

[Peggie Hall HeadMistress]

The easiest hose to work with is Raritan Sani-Flex, little more expensive, but you'll save money on band-aids and ibuprofen, not to mention not offending small children with your language.

SaniFlex is so flexible it can be bent almost as tight as a hairpin without kinking.
And it has 10 year warranty against odor permeation. It's the only hose I recommend any more.

--Peggie

 

[Tedd]

@dlochner and @Project_Mayhem ,

Yes, I used Shields and, yes, it's about as flexible as schedule 40 steel pipe. It would definitely be a royal pain to try to install inside a boat. But fine for this purpose.