Raw/Fresh Water Washdown Plumbing

['84_241_Offshore]

I have a new to me '95 Islander.
During the off season I am getting more familiar w/ the boats systems.
Has a raw water pump contected the washdown hose and the "live well".
The raw water enters the hull and goes to a valve which is connected to a "T". One side of the "T" goes to the Pump and the other to a valve connected to a hose going to the fresh water tank.
So.......if the valve directly connected to the raw water intake is closed and the valve connected to the fresh water tank, fresh water would be supplied to the washdown pump.
Am I understanding this correctly?

 

[seasick]

I don't think so. The raw water should not connect to the fresh water system.

 

[Fishtales]

I have a new to me '95 Islander.
During the off season I am getting more familiar w/ the boats systems.
Has a raw water pump contected the washdown hose and the "live well".
The raw water enters the hull and goes to a valve which is connected to a "T". One side of the "T" goes to the Pump and the other to a valve connected to a hose going to the fresh ??water tank.
So.......if the valve directly connected to the raw water intake is closed and the valve connected to the fresh water tank, fresh water would be supplied to the washdown pump.
Am I understanding this correctly?

You say the raw water goes to a valve with is connected to a T and then to a fresh water tank? I assume you meant to say live well. It sounds like you have a valve that shuts off/on water to both the washdown and live well. A second valve after the T to the live well. If you want both, open both. If you only want washdown, open the seacock and close the live well valve. Sounds like the washdown is always charged and you have the second valve for the live well.

 

['84_241_Offshore]

I will try to draw a diagram........

 

[DennisG01]

Yeah, it doesn't make sense for the raw water and fresh water systems to be buddies. However, that's not to say that some previous owner didn't do something like that. At nearly 40 years old with who-knows-how-many previous owners, all bets are off!

 

['84_241_Offshore]

See if the attachment makes any sense:
1) There is a valve inside the livewell to stop water flow.
2) If valve A is open and B is closed the Pump will be fed by Raw Water.
3) If valve A is closed and B is open the Pump will be fed by Fresh Water.

This is how I assume it works...

 

[SkunkBoat]

If its normal, the freshwater tank has its own pump. Usually hidden somewhere. the plumbing does not interconnect.

 

[Fishtales]

Interesting. If the diagram is what you have, it appears you could run both the livewell and the washdown with either raw or fresh water. The only thing I suggest is adding a check valve so raw water cannot get into the freshwater tank.

 

['84_241_Offshore]

You got it Fishtails......and a check valve makes sense!

 

[seasick]

You got it Fishtails......and a check valve makes sense!

The live well would use up the capacity of the fresh water tank in a short amount of time. I am not I understand what the advantage of that plumbing as described.

Do yu have any fresh water plumbing fixtures like a sink tap or gunnel fresh water hose? If so, where does that plumbing go?

 

[Halfhitch]

I can't imagine any previous owner plumbing that system per the drawing. I agree with all the previous responses, that the freshwater tank should not be connected to the raw water plumbing no way, no how. If indeed that is what you have, I would recommend you get a valid, official diagram of those two systems and plumb your boat accordingly.

 

['84_241_Offshore]

Given all the responses.........I think it's safe to say this set-up is not what Grady had intended.
I don't intend on using the fresh water to fill the live well, however it does give me the option to have fresh water at the wash-down hose for a quick rinse after being in salt water!!

 

[seasick]

As I asked earlier. What did the fresh water tank originally connect to: Do you have a sink faucet or a gunnel shower hose?

 

['84_241_Offshore]

The fresh water tank is also connected to a separate pump for the sink in the cabin and the sink in the head.

 

[seasick]

That part makes sense.
If your diagram is accurate and I don't doubt you.,I just don't see a logical reason for it. It would be possible to pull raw water into the fresh water system should one of the valves be left in the incorrect position. Personally, I would plumb as originally manufactured..

 

[Fishtales]

The live well would use up the capacity of the fresh water tank in a short amount of time. I am not I understand what the advantage of that plumbing as described.

Do yu have any fresh water plumbing fixtures like a sink tap or gunnel fresh water hose? If so, where does that plumbing go?

I'm thinking it would be for the washdown only. You would turn the valve to the livewell off.

 

[Fishtales]

I'm thinking this is a model that didn't have a freshwater washdown. The way the previous owner did it was pretty ingenious if I'm understanding it correctly. He got both a fresh and raw water wash down with the same pump and hose. Just shut off the livewell valve and the seacock and use the freshwater or shut off the freshwater and open the seacock for raw water.

 

['84_241_Offshore]

I agree Fishtales.........and that's the way I intend to use it!

 

[seasick]

When you get sun screen in your eye and go to the sink to give them a rinse, you will get some or all sea water
It is an interesting concept I suppose but to make it better, you could replace the T with a Y valve. You will not need either of the on/off valves but ot wouldn't do any harm to leave them. One side of the Y valve is raw and the other is fresh. IT's a lot less confusing.

I did look up the original specs and the 32 gallon fresh water tank was standard but the deck 'shower' was not. To add the fresh washdown would require a tubing run all the way to the pump and since I think that is in the cabin area, that would be a challenge.

Y

 

[Fishtales]

sounds right. i'm sure you get salt when you want fresh and vice versa. part of the risk you take!