View Full Version : Two pumps - one inlet?
OrangeJaybird
22-11-2021, 05:54 PM
Hi all,
I currently have a pump that’s ’dual use’ in that it does both the live well and also the deck wash.
It recently died, and my mechanic said it’s probably best to have separate pumps (as live wells need volume but not pressure, and deckwash needs pressure but not volume).
He’s quoted me about 2.5 times the cost of the parts to install it (which I can’t stomach, as the rest of quote is north of $5k) so I was thinking of doing it myself.
Is the best way to mount a t-piece from the inlet, and run both pumps from that? Would the t-piece need a valve to isolate each pump so it primes (it’s already got a balcock to stop water getting in if we need to)?
disorderly
22-11-2021, 06:28 PM
I also have the same issue am am looking at the best way of adding a livewell pump..
How else could you do it other then a T piece and why would you need isolation valve ...wouldnt the deckwash only operate once the handle was squeezed and the livewell pump would be on a switch, wouldnt it..?
scottar
22-11-2021, 07:02 PM
Several of the livewell pumps incorporate a take off for a deckwash. All of the low current draw livewell pumps (to my knowledge) will not self prime so need to be mounted below the water line - normally screwed into the inboard side of an isolation valve attached to the skin fitting and the deckwash hose tail screws directly into the pumps take off port.
OrangeJaybird
22-11-2021, 07:02 PM
I also have the same issue am am looking at the best way of adding a livewell pump..
How else could you do it other then a T piece and why would you need isolation valve ...wouldnt the deckwash only operate once the handle was squeezed and the livewell pump would be on a switch, wouldnt it..?
Well I guess my only concern is about primping - if one pump is “on” but the other isn’t, will the ‘off’ pump allow air into the system so the ‘on’ pump won’t prime?
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scottar
22-11-2021, 07:04 PM
I also have the same issue am am looking at the best way of adding a livewell pump..
How else could you do it other then a T piece and why would you need isolation valve ...wouldnt the deckwash only operate once the handle was squeezed and the livewell pump would be on a switch, wouldnt it..?
The isolation valves stop you from sinking - isolate the skin fitting in the case of a leak. They should be the first thing screwed to a skin fitting - before any hose is installed.
OrangeJaybird
22-11-2021, 07:05 PM
Several of the livewell pumps incorporate a take off for a deckwash. All of the low current draw livewell pumps (to my knowledge) will not self prime so need to be mounted below the water line - normally screwed into the inboard side of an isolation valve attached to the skin fitting and the deckwash hose tail screws directly into the pumps take off port.
Thanks Scottar - I’ve just seen those! Those look like the go!
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OrangeJaybird
22-11-2021, 07:06 PM
The isolation valves stop you from sinking - isolate the skin fitting in the case of a leak. They should be the first thing screwed to a skin fitting - before any hose is installed.
Yeah I have that already, but was wondering if I need an additional 3 way isolation valve to isolate the pumps, but your two-port suggestion on the livewell pump is a really good idea.
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scottar
22-11-2021, 07:12 PM
Yeah I have that already, but was wondering if I need an additional 3 way isolation valve to isolate the pumps, but your two-port suggestion on the livewell pump is a really good idea.
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Never seen a problem with a properly installed pump below the water line but your spray head in the tank should incorporate some sort of valve so you can turn the water off under way if you wish without having to isolate the input - centrifugal pumps will allow water to flow through under pressure. If need be at any stage you can prevent air coming in there.
Alchemy
22-11-2021, 07:52 PM
On my last boat I had the deck wash plumbed up to do both live well and deck wash duties and it worked perfectly. I used a timer for the live well operation, and if if I needed the deck wash I’d just flick the lever to stop flow to live well, and switch to manual on the timer.
re pumps failing below waterline; this happened to me on my Fisher. The pump body cracked and flooded the centre bilge. Fortunately the outer two kept me afloat. The area where the pump was, was not easily accessible and the pump didn’t have a ball valve to isolate it.
OrangeJaybird
22-11-2021, 08:24 PM
Never seen a problem with a properly installed pump below the water line but your spray head in the tank should incorporate some sort of valve so you can turn the water off under way if you wish without having to isolate the input - centrifugal pumps will allow water to flow through under pressure. If need be at any stage you can prevent air coming in there.
Thanks Scottar. Both have an isolation - The Livewell has one just before it enters the livewell tank, and the deckwash has one on the hose outlet.
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OrangeJaybird
22-11-2021, 08:25 PM
On my last boat I had the deck wash plumbed up to do both live well and deck wash duties and it worked perfectly. I used a timer for the live well operation, and if if I needed the deck wash I’d just flick the lever to stop flow to live well, and switch to manual on the timer.
re pumps failing below waterline; this happened to me on my Fisher. The pump body cracked and flooded the centre bilge. Fortunately the outer two kept me afloat. The area where the pump was, was not easily accessible and the pump didn’t have a ball valve to isolate it.
Oh wow. Luckily ours is below the waterline (i think) so should be all good there.
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scottar
22-11-2021, 08:37 PM
re pumps failing below waterline; this happened to me on my Fisher. The pump body cracked and flooded the centre bilge. Fortunately the outer two kept me afloat. The area where the pump was, was not easily accessible and the pump didn’t have a ball valve to isolate it.
That would have been a somewhat interesting phone call with the installer if it was mine.............
disorderly
22-11-2021, 08:47 PM
On my last boat I had the deck wash plumbed up to do both live well and deck wash duties and it worked perfectly. I used a timer for the live well operation, and if if I needed the deck wash I’d just flick the lever to stop flow to live well, and switch to manual on the timer.
re pumps failing below waterline; this happened to me on my Fisher. The pump body cracked and flooded the centre bilge. Fortunately the outer two kept me afloat. The area where the pump was, was not easily accessible and the pump didn’t have a ball valve to isolate it.
Well that would have sucked ...it was a livewell pump rather then a bilge pump that failed..?
with your deckwash pump serving both purposes you didnt find it pumped too much water and used to many amps..?
Alchemy
22-11-2021, 09:31 PM
Well that would have sucked ...it was a livewell pump rather then a bilge pump that failed..?
with your deckwash pump serving both purposes you didnt find it pumped too much water and used to many amps..?
Yes, it sucked. I found it as we arrived at the Palms, so turned around and went back to Townsville. Def live pump. It was one of those with the threaded pick up that goes through transom, if that makes sense. Re the deck wash as live pump; I never felt it delivered too much water and didn’t measure current draw.
Lovey80
23-11-2021, 02:07 AM
I currently use my deckwash pump for dual use. With a set of valves after the pump. It’s the expensive Marco type that Moose sold a while back. I think I am going back to the old way and using it just for deck wash duties and using a plain old bilge pump mounted below the waterline on the outside of the hull on the transom. The only down side is that it won’t pump when on the plane which isn’t a big issue in the creek/bay boat.
I find things like herring last WAY longer if they constantly have fresh water pumping in and flushing the scales out. With the Marco pump it can pull up to 25 Amps so not good on the battery if you’re in a spot for a few hours on spot lock as well.
scottar
23-11-2021, 06:53 PM
I currently use my deckwash pump for dual use. With a set of valves after the pump. It’s the expensive Marco type that Moose sold a while back. I think I am going back to the old way and using it just for deck wash duties and using a plain old bilge pump mounted below the waterline on the outside of the hull on the transom. The only down side is that it won’t pump when on the plane which isn’t a big issue in the creek/bay boat.
I find things like herring last WAY longer if they constantly have fresh water pumping in and flushing the scales out. With the Marco pump it can pull up to 25 Amps so not good on the battery if you’re in a spot for a few hours on spot lock as well.
Drill a hole central in the pumps base and mount it on a bracket with a scoop and it will pump on the plane without issue.
Dignity
23-11-2021, 07:56 PM
Drill a hole central in the pumps base and mount it on a bracket with a scoop and it will pump on the plane without issue.
Like this
125004
I've been down the path of using a single pump for both functions but eventually gave it up due to pressure/volume differences required for deckwash and bait pump didn't give me what I wanted.
gazza2006au
23-11-2021, 09:11 PM
$5,000 to install a bait tank pump and a deck wash pump? That is quiet some money for installing two simple pumps i can see why your doing it your self
This is abit of a good topic as i still have pilchard guts all over my boat all dried up, i shouldhave got the boys to wash down there mess after we headed back in
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