Bilge pump preference - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 12-06-2008 Thread Starter
Senior Member
 
Shortman's Avatar
 
Join Date: Feb 2006
Location: Western MA & Maine
Posts: 167
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
Bilge pump preference

I have a Rule non-automatic 1000 GPH with a standard float switch. Has generally worked OK, with some problem in cavitation when heeling.
What do you have, what do you like? Automatic w/integral switch? External switch, float, electronic? Brands?
Shortman is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 17 Old 12-06-2008
Senior Member
 
Join Date: Dec 2006
Location: Seaside, Florida
Posts: 3,331
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
   
I like a remote switch if only to keep the pump in more protected place. Mine is a $130 Jabsco and it seems to work fine.
sailhog is offline  
Quote Quick Reply Share with Facebook
post #3 of 17 Old 12-06-2008
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
It really depends on what you're going to be using said bilge pump for. The small ones with an integrated float switch are great for maintenance bilge pumps, where they just take care of the day-to-day drips and leaks into the bilge, but for an emergency bilge pump, you'd probably want it with an external float switch and much higher capacity.

Rule, Jabsco, etc. are all pretty decent, but just remember that the pump's GPH rating is usually for ZERO LIFT.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #4 of 17 Old 12-06-2008
Closet Powerboater
 
MedSailor's Avatar
 
Join Date: Mar 2008
Location: Anacortes PNW
Posts: 3,556
Thanks: 256
Thanked 111 Times in 100 Posts
Rep Power: 8
 
I'm a recovering wooden boat owner so I know a lot about bilge pumps. ;-)

I have to say that without reservation I recommend rule. I tried a couple other brands and under my hard use/abuse they all died eventually. The two rules that came with the boat (1500 and 2000) were still going strong after 5 years of ABUSE. Once I came back from a week long trip and found it running dry with a stuck float switch. It was fine. They both saved the boat more times than I am willing to admit.

Switches are another issue. I probably went through 15 or so. The only one I really liked was the electronic switch by Johnson called the ultima. That and the old type that have a metal ball that you can hear roll from end to end when the switch is lifted. All the rest crapped out in no time.

Remember always have 2 (or more) electric bilge pumps wired to different batteries.

Medsailor

I have a sauna on my boat, therefore I win.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MedSailor is offline  
Quote Quick Reply Share with Facebook
post #5 of 17 Old 12-06-2008
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,877
Thanks: 20
Thanked 219 Times in 167 Posts
Rep Power: 16
       
Don't forget high water alarms. I use three WatchDog Water Alarms (LINK) alarms on my boat and they are very, very loud similar to a smoke detector and they can be heard over the noise of the engine! I have one three inches off the bottom of the bilge, one in the engine compartment and one in the head.

As far as bilge pumps go I think we need to be very careful taking any centrifugal pump at face value. Having two large pumps a wise idea with centrifugals!

Flow rates, as rated by bilge pump makers, can be quite misleading. They should serve only as a rough guide of a pumps "best case" capacity compared to others of similar design.

Bilge pump capacity is usually rated as “open flow” or what's called “open bucket” rate. This means the figures account for no, nada, zero vertical lift and also no discharge hose friction, radiused bends or discharge outlet restriction.

Actual flow rates, under real operating conditions, can be drastically lower. Water must be lifted up and out of the bilge and then be pushed through lengths of hose to the discharge point. This resistance is called head. Head pressure is basically the weight of the water and the frictional resistance of the hose, bends and outlet. Most centrifugal pumps, like the ones made by Rule or Johnson Pumps, have large internal tolerances to allow passage of bilge crap, so their flow rate decreases dramatically with increases in head. Unlike a vane pump, which would be less affected by head loss, the pumps rotor or impeller does not come in direct contact with the pumps walls. Impeller/vane pumps and diaphragm pumps are less affected by head pressure than a centrifugal pump is and they may actually be more effective despite a lower "labeled" GPH rating. Some of the vane/impeller pumps can handle 60+ feet of head pressure with ease. Because of the large tolerances in centrifugal pumps it can lead to, and create, cavitation if the head pressure is extreme enough.

I'm sure many of us have seen the bilge pump kick on and then not actually suck any water but instead just create noise and bubbles in the bilge. This can usually be eliminated by removing those ridiculous head boosting flow checks and the crappy corrugated bilge hose and replacing it with smooth walled hose..

The output of many centrifugal bilge pumps can diminish by as much as half with only a few feet of head and can stop entirely at between 13 and 20 feet, depending on the size of the bilge pump. Remember head is not just the peak height/lift of the hose it is the friction, height, bends and fitting restrictions all added together.

Another serious consideration is voltage. What is your pump rated at? Is it 14.2 volts or 12 volts. This will and can make a difference as the pumps motor increases and decreases output based on voltage.

There have been a few tests like the ones conducted by West Marine. They rated pumps based on voltage and head pressure. Most manufacturers ratings (open bucket / no head ratings) were off between 10-50%. the output on average was reduce by about
5% for every foot of head pressure. With voltage the drops from 13.6 volts to 12.2 volts were another 15-30% off on top of the head pressure loss. So your 800 GPH centrifugal pump may not even deliver 1/3 of that rating in a real word situation..

I guess what I'm getting at is this; unless you have a "monster truck" grade bilge system, do not count on anywhere near the face value rated capacity from your bilge pump.

Some other things to consider:

- Use smooth walled discharge hose as it has significantly less head resistance than does corrugated.

- If the discharge outlet is close to the waterline you must use a high loop in the discharge hose to prevent siphoning. It is advised to add a siphon break at the highest point to ensure it won't siphon. Even with a high loop a bilge pump can still siphon without a siphon break. I have been on more than one boat that self siphoned when under sail and power.

- Do not succumb to the temptation of using a "check valve" with a centrifugal pump. If you have 5' of height, in a 1" hose, the pump will more likely than not cavitate before it can throw open that check valve with that standing water behind it..

Disclaimer: Many years ago I used to sell a line of submersible pumps to the plumbing and well supply wholesale distribution channels.

______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.



Last edited by Maine Sail; 12-06-2008 at 09:06 PM.
Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #6 of 17 Old 12-06-2008
Senior Member
 
Join Date: Jan 2001
Posts: 507
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 15
 
I have a Rule "automated" pump in a boat that collects a lot of rain water. It has an internal sensor that makes the pump come on when the water level rises and keeps it running 20 seconds after the water level drops so it cycles less. I don't like seperate float switches as they can get pinned under someting that prevents them from coming on, or get something stuck under them so the pump never goes off and leaves you with a dead battery. On my old wooden boat, I had Lovett pumps that worked hard, and never failed. If I had room, they'd probably be my first choice.
Quickstep192 is offline  
Quote Quick Reply Share with Facebook
post #7 of 17 Old 12-07-2008
Senior Member
 
Pamlicotraveler's Avatar
 
Join Date: Aug 2006
Location: Creedmoor NC
Posts: 607
Thanks: 5
Thanked 1 Time in 1 Post
Rep Power: 9
 
We have the Ultra Sr. pumpswitch by Ultra Safety Systems, and from everything I have heard or experienced they are bullet proof. A bilge pump is pretty important of course and the Ultra Sr. has a High water alarm. Our is sent way down into the bilge.

Twenty years from now you will be more disappointed by the things y%^&*.....oh never mind. 90% of the people on sailing forums already use that as their signature! I'm not a conformist.
Pamlicotraveler is offline  
Quote Quick Reply Share with Facebook
post #8 of 17 Old 12-09-2008
Senior Member
 
nightowle's Avatar
 
Join Date: Aug 2006
Posts: 226
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 10
 
pump placement question for Mainsail???

QUOTE:

- If the discharge outlet is close to the waterline you must use a high loop in the discharge hose to prevent siphoning. It is advised to add a siphon break at the highest point to ensure it won't siphon. Even with a high loop a bilge pump can still siphon without a siphon break. I have been on more than one boat that self siphoned when under sail and power.

- Do not succumb to the temptation of using a "check valve" with a centrifugal pump. If you have 5' of height, in a 1" hose, the pump will more likely than not cavitate before it can throw open that check valve with that standing water behind it..

Disclaimer: Many years ago I used to sell a line of submersible pumps to the plumbing and well supply wholesale distribution channels.[/QUOTE]

Mainsail: I wanted to ask you about having the discharge close to the waterline. I will be installing a Whale pump that is designed for shallow bilges. I'd like to 't' into the sink discharge through hull which is only about 4 feet from where the pump will be and I'll avoid having to create another hull opening. Will I still need to put high loop in the discharge hose even if the pump has a check valve?

Thanks

________
S/V Don't Panic!
O'Day 27
Seattle, WA

“Navigare necesse est, vivere non est necesse” To Sail is vital, to live is not.
nightowle is offline  
Quote Quick Reply Share with Facebook
post #9 of 17 Old 12-09-2008 Thread Starter
Senior Member
 
Shortman's Avatar
 
Join Date: Feb 2006
Location: Western MA & Maine
Posts: 167
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
yes, high loop

I'll chime in on the question to Maine Sail. Yes high loop, because if the check valve fails, you gonna have a wet boat.
Practical Sailors sister publication, Power Boat Reports, tested a bunch of pumps and reported data on much of what Maine Sail is talking about 20 Electric Bilge Pumps Tested
I do have a check valve because the discharge line is Tee'd into the shower sump line and then the single line has a vented loop. I will probably give it it's own vented loop then tee the lines right before the thru hull.
One of my main interests in the original question is the switching. Integral within the pumps certainly seems less to maintain. The electronic ones would seem to offer better reliability.
Shortman is offline  
Quote Quick Reply Share with Facebook
post #10 of 17 Old 12-09-2008
1977 Morgan OI 30
 
Joesaila's Avatar
 
Join Date: May 2007
Location: Massachusetts
Posts: 438
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Quote:
Originally Posted by Maine Sail View Post
Don't forget high water alarms. WatchDog Water Alarms (LINK)[/URL] alarms on my boat and they are very, very loud similar to a smoke detector and they can be heard over the noise of the engine! I have one three inches off the bottom of the bilge, one in the engine compartment and one in the head.
Thanks for the tip Maine Sail! I didn't know about water alarms and will get one for the boat and my basement. Inexpensive too via Home Depot. And the smooth hose makes sense too.

Thanks Pamlicotraveler for the tip re Ultra Safety Systems. I use Rule but will grab one of those switches! ...good post!

My formula for living is quite simple. I get up in the morning and I go to bed at night. In between, I occupy myself as best I can.
Cary Grant

Last edited by Joesaila; 12-09-2008 at 06:55 AM.
Joesaila is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Devising a Better Bilge Pump Don Casey Seamanship Articles 0 06-02-2002 08:00 PM
Devising a Better Bilge Pump Don Casey Gear and Maintenance Articles 0 06-02-2002 08:00 PM
Devising a Better Bilge Pump Don Casey Cruising Articles 0 06-02-2002 08:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome