Y together two bilge pumps?

[OldDan1943]

Manifold? In the moment of stress, I dont need to fiddle with a valve manifold. One bilge pump, one discharge.
Just my opinion.... IF you have two bilge pumps in a compartment, one discharge to port, one to starboard. Centrifugal pumps do not like to pump against pressure.
I am not in favor of hull valves for the discharge of the bilge pumps, and IMO, never use a check valve in a bilge pump discharge line. They just may fail shut when you really need to really need to get the water off the boat.

 

[Fish53]

Manifold? In the moment of stress, I dont need to fiddle with a valve manifold. One bilge pump, one discharge.
Just my opinion.... IF you have two bilge pumps in a compartment, one discharge to port, one to starboard. Centrifugal pumps do not like to pump against pressure.
I am not in favor of hull valves for the discharge of the bilge pumps, and IMO, never use a check valve in a bilge pump discharge line. They just may fail shut when you really need to really need to get the water off the boat.

If you need to pump and you're taking water to the point it's "a moment of stress" and you want to be limited to one pump it better be a very big one. As can be seen on the flooding graph I posted elsewhere real ingress of water needs a real pump. Your average Rule 1500 automatic pump that in truth will only pump maybe 10 gallons a minute is a pretty poor piece of emergency equipment. A 2" hole 2' below the waterline let's in over 100 gallons a minute, that's 6000 gallons an hour. The reality is bilge pumps are not emergency equipment, and won't save your boat in the case of real damage from a grounding, collision or if a hose breaks coming from a seacock. They're primarily just to remove the small accumulation of water in the bilge periodically.

 

[OldDan1943]

Fish, I agree with you. Bilge pump selected/designed so that it will give you a chance to do 'something' else to to reduce or eliminate the incoming water.

"a moment of stress" occurs, in my mind, is when water is coming into my boat, regardless of the source. SMILE

 

[Mako]

This is primarily to remove the water that never leaves the boat (rain water that gets in the hatch)

Tom, getting back to these few words. Wouldn't it best to eliminate the problem instead of trying to fix/mitigate/live-with the problem?

A boat's safety depends on its watertight integrity, especially hatches, windows, portlights and doors. Even your packing gland drip should be into a pan which drains to the shower sump pump.

There's no reason not to have 100% dry bilges. My steel and wood was tight. Even painted the bilge bright white (which I personally hated) because dried up drips show as yellow stains easily.

 

[Blissboat]

I agree with the practice of "one bilge pump, one discharge - two bilge pumps, two discharges." There should be nothing fancy or complicated about a system as fundamental as a bilge pump, especially if it supposed to work by itself, unattended.

It's true that on inspected / commercial vessels, a bilge manifold system of steel pipes running to multiple compartments connected to a single pump is legal. But, the context is different from our recreational boats. For one thing, manifold systems are not unattended automatic pumps. Typically the commercial vessel is crewed and maintained by someone whose hands and eyes are actually on the bilge pump whenever it is operating.

 

[Fish53]

I agree with the practice of "one bilge pump, one discharge - two bilge pumps, two discharges." There should be nothing fancy or complicated about a system as fundamental as a bilge pump, especially if it supposed to work by itself, unattended.

It's true that on inspected / commercial vessels, a bilge manifold system of steel pipes running to multiple compartments connected to a single pump is legal. But, the context is different from our recreational boats. For one thing, manifold systems are not unattended automatic pumps. Typically the commercial vessel is crewed and maintained by someone whose hands and eyes are actually on the bilge pump whenever it is operating.

There exists a very large class of inspected/commercial vessels that do not have a manned engine room, have a bilge piping system and do not have bilge pumps that require someone actually at the pump. In fact it would be a decided disadvantage to require someone at the pump in a case of flooding. The real reason for a more robust pumping system is dewatering in cases of flooding from damage rather than ridding the bilge of a little rainwater or stuffing box leakage. For those interested a source is the "Boat Mechanical Systems Handbook" by Dave Gerr which addresses this issue with clarity and in the context of vessels of the size common on this site.

 

[Art]

Removing the final bits of water with bilge pumps to me is not the way to go.

For my whole recreational and pro career...I never really gave the dri-bilge concept a second thought.

Once I saw the DIY projects here and on YouTube, I had everything on hand except the $30 pump. So I tried one out.

Never been happier and never had a dry bilge like now.

The beauty of the setups is they can be rigged for multiple pickup stations and not the complexity or expense of the larger bilge pump setups that will still never get all the water out.

Sure adding bilge pumps with check valves can be done but I would never T in with check valves. Either connect them past the loop that drains overboard or make one tiny and pump it into a sump like a shower sump that pumps overboard.

Maybe I missed it - Got a link or video name to look up>>

 

[psneeld]

One that I adapted...



https://lifeempirically.com/2018/03/12/build-your-own-diy-arid-bilge-or-dry-bilge-system/

 

[OldDan1943]

I guess I am in a minority. I would never consider a Y nor a check valve.
Just my opinion.

 

[stubones99]

or:

I would use a peristaltic pump instead of the pump he used. Low volume, quiet, and won't ever back flow when the power is disengaged.

 

[Barking Sands]

I made a dry bilge type system from scratch using a basic diaphragm pump. I went to home depot and got a large plastic piece from the HVAC section and a large sponge and a few fittings. I wanted something larger than the one in the video above so there would be more filter area. I also wanted the sides enclosed to allow for better suction. Its been in place for probably 6 months and has been perfect. I have some fesh water leaks when it rains. I have eliminated about 90% of the leaks but there are stil a few that remain. My cockpit hatch and front windlass area still have a few minor spots where water gets through. I doubt I will ever get this "leaky Teaky" to be perfectly waterproof. So the dry bilge has been fantastic. Its made it so that every time I go to the boat its possible to vacuum the bilge and keep it free of crap that might clog up the main and emergency bilges. It also keep the two bilges from sitting in 1/2 inch of water at all times.

https://youtu.be/KkRvJpzo8CQ