Bilge pumps and hoses questions

[sndog]

I am installing several new bilge pumps in my boat. Originally it had 2 Rule 2400's. One in the port engine bay bilge and one starboard engine bay bilge area. They went to some contraption that was also the kitchen sink drain, then through an above-water thru-hull. Both used cheap bilge hose.

I am replacing those with Seaflo low narrow profile 1100 GPHs, along with Seaflo's 4700GPHs pumps. The larger flow will be the mid-water pumps. There will also be a 6600GPH AC sump pump for high water in each location controlled with a 12vdc float switch.

For my aft cabin space, it will be the Seaflow narrow profile 1100GPH, one Seaflo 4700GPH, and one 5400GPH AC Sump pump, controlled with a 12vdc float switch.

For my bow bilge space, it will be the Seaflow narrow profile 1100GPH, one Seaflo 4700GPH, and one 6600GPH AC Sump pump(maybe 2), controlled with a 12vdc float switch.

For my midship bilge space, it will be the Seaflow narrow profile 1100GPH, and two 6600GPH AC Sump pumps, controlled with a 12vdc float switch.

I have tried to figure out if there is a bilge pump exit water manifold system I could use, but have not found any info. If anyone here has any ideas, I would appreciate them, or I will be putting in a bunch of new thru-hulls.

In addition, I have been looking at what type of tubing to use, and am looking at either Tigerflex, PVC pool line, or using PVC SCH80 pipe for the long runs and connecting to the pumps and the thru-hulls with flexible pipe.
Was wondering if there is a preferred, or better, way.
Outputs on pumps are 1.5", is that sufficient size for the hose ID as well?

Thru-hulls will be about 14" above the water line. AC sump pumps are Ridgid 1HP.

 

[Comodave]

I would put in a through hull for each pump. It isn’t recommended to gang them up into one through hull. As to 1.5” hose, I use SaniFlex hose because it is smooth bore and bery flexible. It is more expensive than PVC but so much easier to bend.

 

[Pete Meisinger]

Go with the saniflex. You are installing pretty high capacity pumps I would go with a very minimum of 1 inch, larger would be better. Do not marry them with a manifold of any kind. Since the thruhulls will be above waterline a few extra holes in your hull shouldn't worry you. If they are combined there is a real danger of cross flow.

pete

 

[Greg QS]

1. Manifolds do not work. If multiple pumps run at one time, it will reduce the outputs of the pumps, or possibly push water back through a non running pump discharge line.
2. The sanitation line works well.
3 a small maintenance pump works well to keep the water volume low in each bilge for normal bilge water. The second pump is great if your maintenance pump is overwhelmed or fails. The third is a crash pump if all pumps fail or are overwhelmed with water.
4. This would require 9 additional through hulls. As far as placement of them. Remember the higher and the longer the run of the discharge will reduce the ability of the pump to discharge water. Keep the runs short as possible. Install loops above the the discharge with a anti siphon break so water will not be sucked back in. Hard pipe is not recommended and almost impossible to route through a boat anyway.

5. You said the boat had 2 rule pumps in the er by the engines and an odd discharge . Seems to me you have and older vessel with common bilges. If they are not the low points of the ship , maybe consider having a single small pump in each area of the ship for keeping water levels low. Install the larger dc pump at the low collection bilge . Keep crash pump in a higher location in case of a problem or even a mobile pump.


How much pumping is enough? In an event when you need that much water pumping you will probally be abandoning ship. You will have encountered a major event. Every through hull port in a boat is a place for water to enter as it goes down. So more pumps = more water entry points.

Catching the water before the second pump starts is the key. Sounds like you have a common bilge. Find the lowest water point in the boat. Install a small bilge pump (to keep as much water out as possible) . Next Install a high water alarm. This should go off before any other pump turns on. This will protect you from failure of the first or overwhelming of it. Then your first larger pump should run but not turn off the alarm. If you feel you need additional pumps from there its up to you. If when your underway the water collects some where else in the vessel , repeat the assembly there.

Personally in my vessel, I have a single pump in each sump/ sealed bilge area. 7 compartments in all ,22oo gph rules. Each bilge pump sets off an indicator light upon running, Each compartment has a High water alarm set as low as possible. Each compartment has a bilge dry bilge evacuator to keep all water out. I carry an ac sump pump on the boat rigged with 50' of hose. If I have a major failure I place the pump in the appropriate area. I use the same pump in each area. I carry 2 extra new bilge pumps and float switches. If I have a failure of a pump or float, it gets switched out , no need to even change the base.

 

[sndog]

1. Manifolds do not work. If multiple pumps run at one time, it will reduce the outputs of the pumps, or possibly push water back through a non running pump discharge line.
2. The sanitation line works well.
3 a small maintenance pump works well to keep the water volume low in each bilge for normal bilge water. The second pump is great if your maintenance pump is overwhelmed or fails. The third is a crash pump if all pumps fail or are overwhelmed with water.
4. This would require 9 additional through hulls. As far as placement of them. Remember the higher and the longer the run of the discharge will reduce the ability of the pump to discharge water. Keep the runs short as possible. Install loops above the the discharge with a anti siphon break so water will not be sucked back in. Hard pipe is not recommended and almost impossible to route through a boat anyway.

5. You said the boat had 2 rule pumps in the er by the engines and an odd discharge . Seems to me you have and older vessel with common bilges. If they are not the low points of the ship , maybe consider having a single small pump in each area of the ship for keeping water levels low. Install the larger dc pump at the low collection bilge . Keep crash pump in a higher location in case of a problem or even a mobile pump.


How much pumping is enough? In an event when you need that much water pumping you will probally be abandoning ship. You will have encountered a major event. Every through hull port in a boat is a place for water to enter as it goes down. So more pumps = more water entry points.

Catching the water before the second pump starts is the key. Sounds like you have a common bilge. Find the lowest water point in the boat. Install a small bilge pump (to keep as much water out as possible) . Next Install a high water alarm. This should go off before any other pump turns on. This will protect you from failure of the first or overwhelming of it. Then your first larger pump should run but not turn off the alarm. If you feel you need additional pumps from there its up to you. If when your underway the water collects some where else in the vessel , repeat the assembly there.

Personally in my vessel, I have a single pump in each sump/ sealed bilge area. 7 compartments in all ,22oo gph rules. Each bilge pump sets off an indicator light upon running, Each compartment has a High water alarm set as low as possible. Each compartment has a bilge dry bilge evacuator to keep all water out. I carry an ac sump pump on the boat rigged with 50' of hose. If I have a major failure I place the pump in the appropriate area. I use the same pump in each area. I carry 2 extra new bilge pumps and float switches. If I have a failure of a pump or float, it gets switched out , no need to even change the base.

There is no common bilge, hence the multiple areas.

The engine room on each side has low points for the bilge. If it gets high enough, it will overfill into other compartments.

The boat is built in 1995.

Running the hard pipe is surprisingly easy. The boat has room between the bilge fuel tank and the flooring to run the pipe. The bilge fuel tank is also why there is no common bilge and holds about 1500 gallons of fuel.

There should be no water really intruding unless there is an issue. The shaft seals are Lasdrop Gen II, and the rudder seals are PYI. All dripless. Raw water inputs to everything come through two sea chests. The only other underwater thru-hull is the one I just added for black water.

The large pump capacities is in case anything happens. For the 6.6k GPH, I was thinking 1.5" pipe and thru-hull. The 1100gph 3/4" for both. And the mid-size being 1" pipe and thru-hull.

 

[Comodave]

Check out the SaniFlex hose. It is way more flexible than the PVC bilge hose. Although if you don’t need bends then the PVC would be fine. In my case it always seems that I need some tight bends.

 

[sean9c]

Wasn't familiar with Seaflow pumps so I did a little googling. Wow, are they ever cheap, as in inexpensive. A Seaflow 4700 is $110. For comparison a Rule 4000 is about $280. There is a reason they're cheap and it's likely not a good one

 

[sndog]

Wasn't familiar with Seaflow pumps so I did a little googling. Wow, are they ever cheap, as in inexpensive. A Seaflow 4700 is $110. For comparison a Rule 4000 is about $280. There is a reason they're cheap and it's likely not a good one

All the reviews I have found spoke highly of them. I bought a few of the smaller ones and have been playing with them, and they seem to be of decent quality.

My larger pumps are Ridgid pumps. They put out 6.6k GPH. I will use a 12v volt switch to control them though.

For my AC units, I am trying out Jebao DCT Water pump DCT15000. Puts out nearly 4k GPH. I have been running and playing with it now for several months and seems really great. If I do not go with that, I will go with Danner aquarium pond pumps. Much cheaper than the march pumps.

On the scale I am looking at, I am trying to be cost conscience where it makes sense while being protected.