Installation of washdown pump

[pursuit2460]

I am about to install a washdown pump on my boat. My question is what size the water pick up should be. I know I have to install a valve inline of the water pick up but dont know what size to start with 1" -1 1/4- 1 1/2. After that I know I have to reduce to 3/4 to tie into the pump. Also what pumps do you guys recommend. thanks

 

[Bob_VT]

Re: Installation of washdown pump

I had one on a cuddy cabin. The fitting was mounted through the hull (not the keel but about 18" away) and it was a 3/4" pick up just like a bilge pump fitting. After it entered the hull I had it connected to a brass and stainless ball valve. Hull - ball valve - pump - ball valve - 10 gallon poly storage tank - water hose fitting. Worked just fine. The ball valves were so I could remove the pump safely when the system was full of water.

 

[MJ76]

Re: Installation of washdown pump

I wouldn't think it would much matter - a washdown sytem would typically be run with 3/4" I.D. hose, as is the pump input, as you say, so no reason to go any bigger than that. Smaller thru-hull means smaller valve & fittings - may give you a litlle more freedom when choosing the location for the thru-hull fitting, especially on a smaller vessel.

The other thing to consider is the placement with respect to the bottom of the boat. You want to avoid being directly forward of the props, or any kind of transducer.

Jabsco makes a nice sensor pump that provides variable flow based on demand - basically just maintains constant pressure and shuts off when there is no flow.