New video Understanding Bilge Pumps

[Sailvayu]

This is based on a upcoming article I wrtoe for Ocean Navigator's Ocean Voyager issue. Hope it is of use to someone. It is a bit long but I feel has some good information.

http://youtu.be/Fcbd41iDe2Y

 

[Delezynski]

GREAT review video! I did not know about the ABYC change about the alarm.

Greg

 

[Sanman]

Thanks Capt. Wayne, That is a Fantastic video!

 

[Maine Sail]

Wayne,

Good info.. I did not see any mention of check valves, though perhaps I missed it, on centrifugal pumps. Rule specifically suggests not using check valves on their centrifugal pumps..

Last fall I did some centrifugal pump testing using a variable power supply with adjustable voltage and found huge variations in pumping capability based on the type of hose, hose length hose height, elbows and voltage. Many of these centrifugal pumps won't even do 1/3 of their face value rating "as installed"... Can be scary stuff if you think you've got 2000GHP available and find out you really only have 1/3 or less of that after installation.

 

[Sailvayu]

Yes I pointed out that check valves can reduce flow by as much as 50% and are a clogging issue as well, but yet I see them used all the time.

 

[Maine Sail]

Yes I pointed out that check valves can reduce flow by as much as 50% and are a clogging issue as well, but yet I see them used all the time.

Sorry I missed that part, I was watching it while on hold...

I see them installed to and I yank them out all the time when pumps refuse to do what they need to do ..... PUMP..... It is amazing to me that builders install check valves when Rule is very open about not recommending them for their pumps..

 

[Sailvayu]

I agree, I think builders use them because it is an easy solution to pump cycling. Unfortunately most builders install pumps to remove nascence water only. Owners need to know these pumps are not really adequate to deal with emergencies. I think the report from the Bounty drives home the lessons on needing a good WORKING dewatering system.

 

[Blitz]

Great video

Wayne,

Good work on video. I've been subscribed for some time, all your videos are very useful.

Good comparison of pumps that makes me think about the advantages of an electric diaphragm pump as getting more of the water out and prevent cycling. I hear they jam easily?

I have struggled as well with the cycling issue you speak of in video. I see you recommend for sailboats to exit the bilge high and through the transom of sailboats. This of course adds to the back flow problems due to the long bilge discharge line (or at least for me since deepest part of shallow bilge is midship) Would you ever think it would be ok with the discharge below the waterline with a vented loop for discharge midship with a centrifugal or diaphragm pump? (Funny that a vented loop is a tip in new 2014 West Marine catalog)

Bilge alarm and indicator light at helm's chart plotter navpod is on my list to do.

Thanks - Neal

 

[Sailvayu]

Yes a vented loop is an option, but in my mind just adds more restrictions. Of course as with most things on a boat you have to reach a compromise. Maybe you could use the diaphragm for removing the water from the sump them mount a larger centrifugal a bit higher up to handle possible flooding problems. In my boat I have a Rule mate 2000, this pump runs for a few seconds after it sucks air and just long enough to clear just enough to prevent cycling. It can also help to put a bit of a loop in the hose before it drops into the bilge to prevent all the water from running back into the sump. It can take a little screwing around but most of the time you can get around a check valve. Good luck and let us know how you make out and what you end up doing.

Oh and thanks for being a subscriber I have some good plans for future videos. Glad you enjoy them and hopefully I am getting a little better with time lol

 

[Tom J]

Bilge Pumps

Unfortunately, Catalina installed a check valve and a 90 degree elbow in my bilge pump circuit. After reading Main Sail's recommendations last year, I tried running my pump (Rule 800) without the check valve and the 90. It was impossible, however, to prevent short-cycling of the pump in this configuration. In essence, it would never shut off. I ended up with a new Atwood pump with the check valve and the 90. I'm aiming for a parallel system with a diaphragm pump for next season.
I did install a high water alarm, with visual and audio alarms at the helm station, several years ago.
Thanks for the great video, Capt. Wayne. It answers a lot of questions I had about these installations.

 

[Tom J]

Correction. The bilge pump alarms are mounted at the nav station. The larger red LED is for the original bilge pump circuit, and the smaller red LED is for the high water alarm.

 

[Sailvayu]

In a case like that I might suggest a diaphragm for the lower nascence water and a large centrifugal for emergency back up use. Hope you have at least 1 manual pump as well. Nice to see the clean bilges and a good install with the wires secured out of normal water level.

 

[Tom J]

In a case like that I might suggest a diaphragm for the lower nascence water and a large centrifugal for emergency back up use. Hope you have at least 1 manual pump as well. Nice to see the clean bilges and a good install with the wires secured out of normal water level.

Thanks, Wayne. The Catalina did indeed come with a nice manual pump (Whale, I believe) mounted near the helm.

 

[vtsailguy]

Very nice.

I did a bilge pump video a while back as a real world calculation if you had a hole in your boat:
http://www.youtube.com/watch?v=6ubkobmu_Cw

Basic upshot... pumps don't deal with water intrusion, they just give you time enough to plug it.

Pumps can never keep ahead of a hole.

 

[Maine Sail]

In a case like that I might suggest a diaphragm for the lower nascence water and a large centrifugal for emergency back up use. Hope you have at least 1 manual pump as well.

Bingo!!

Diaphragm pumps are not fast but they are far less affected by head loss than a centrifugal pump thus can pump closer to their rating, even against more head. They can also pump through a check valve with ease and by design sort of act as a check valve.

Centrifugal pumps can move lots of water but deal horribly with any head resistance and need smooth hose, good voltage, minimal hose rise, minimal turns and no check valves to perform as they should..

 

[Sailvayu]

Nice little video vtsailguy, and does drive home the point. I always suggest owners throw a garden hose into the bilge turn it on full blast and then see if they can keep up with the flow with all their pumps including manual ones. Many are surprised at just how quickly they lose ground. Now imagine doing that at sea with even just 3 foot waves in the dark and you begin to understand just how pitiful most dewatering systems are. Thats why I push for a high water alarm the quicker you know you have a problem the quicker you can deal with it. Will Keene of Edson also suggests you do this with manual pumps alone with your real crew ans see just how long you can keep pumping away, I bet most are surprised at how fast they become exhausted.

 

[vtsailguy]

Yes, I remember a quote from some old book I read:

"Nothing bails faster than a crew with a 5 gallon bucket and fear in his eyes"

Then there is the other story of being on a lifeboat and the captain would pull a plug out and the crew had to continuously bail. It focused them on their survival.