Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 10-09-2009, 05:15   #1
Registered User

Join Date: Jul 2009
Location: SW Florida U.S.A
Boat: none(fornow)
Posts: 192
Bilge Pump Hose Length

After reading about how wimpy bilge pumps are and looking at the specs for my pump I am a little concerned that my hose run may be too long. First my pump is a Rule 360 gph but the specs for the pump seem to put the output somewhere between 0 and 100 gph with a 12 foot hose run with a rise of about 12 inches. I think I might have to test the pump to check it's flow, I just am not sure how I should test it. Should I intentionally put some water in the hull to check it's flow? I am more concerned about it's pumping ability while the boat is anchored while I am not onboard.
__________________
kcmarcet is offline   Reply With Quote
Old 10-09-2009, 06:48   #2
Registered User
 
S/V Illusion's Avatar

Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 1,693
It has very little to do with the hose length (as long as you use smooth hose) and everything to do with the head against which the pump has to push. At no head, your pump will push 360 gph theoretically. Measure the rise between the pump and discharge and any additional head from the backflow loop and you can easily read the advertized pump rate. If you have a check valve, it will be less still.
Fill up the bulge with water and test it. That should be part of your normal maintenance routine anyway.
__________________
S/V Illusion is offline   Reply With Quote
Old 10-09-2009, 09:02   #3
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,577
Images: 240
Quote:
Originally Posted by S/V Illusion View Post
It has very little to do with the hose length (as long as you use smooth hose) and everything to do with the head against which the pump has to push...
FRICTION LOSS IN WATER HOSE

At 5 GPM water flow (360 GPH) a clean 1-1/4" I.D. smooth hose will have
about 0.765 Feet of Head Friction Loss (0.32 PSI Pressure Drop), per 100 foot of hose.
The same 5 GPM discharge through a 1" I.D. hose will have about 2.194 Feet of Head Friction Loss (0.95 PSI) per 100'.

See Dave Gerr
's

Boat Mechanical Systems Handbook
Boat Mechanical Systems Handbook ... - Google Books

http://www.ppt-hose-tech.com/Downloa...ion%20Loss.pdf
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Reply

Tags
bilge, bilge pump

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bilge Pump Placement kcmarcet Plumbing Systems and Fixtures 23 15-09-2009 12:10
Backflow from Bilge Pump KevinE Construction, Maintenance & Refit 16 17-07-2009 15:13
Second Bilge Pump bcguy Plumbing Systems and Fixtures 1 27-05-2009 14:23
Bilge Pump Carpy0126 Powered Boats 2 08-05-2009 22:08
bilge pump dilemma jimbim Plumbing Systems and Fixtures 15 27-10-2008 06:17



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:43.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.