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Bilge pump hose ribbed?

Apr 28, 2005
236
Oday 302 Lake Perry, KS
Somewhere I suspect I have a leak in my bilge pump hose (after the pump runs, the water returns). So, it's likely time to replace the hose.
All the replacement hose I can find (Amazon, eBay, West Marine etc.) seems to be the ribbed style. I suspect the ribbed hose is more flexible? But wouldn't the pump be more efficient if the hose were smooth?
Or does this really matter when I'm pumping about 12-14 feet horizontally with a rise of no more than abouit 2 feet?
 
Oct 2, 2008
3,004
Pearson/ 530 Strafford, NH
Do you mean ribbed outside, smooth inside? Is the amount of water equal to what is left inside the hose after a cycle? Do you have a vented loop in the line? And lastly, are you sure there are no other leaks?
 
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Feb 8, 2014
1,080
Columbia 36 Muskegon
It's normal for whatever water that's in the hose to run back out after the pump stops. On my boat the way the PO ran the hose that was enough to turn the pump back on. It would just pump the same water back and forth all day long. A check valve would prevent that, but they restrict the flow so not a good idea. And I'm in Michigan so I would have to remove the check valve to winterize. If you can reroute with the highest spot soon after the pump the back flow will be minimized. Outlet needs to be above water to prevent siphoning. The solution I used was a small pump with small hose and as short and direct a route as possible. It only holds a few ounces to flow back and handles any nuisance water. The big emergency pump is mounted higher with it's own float switch and it never comes on.
 
Jan 11, 2014
4,053
Sabre 362 113 Fair Haven, NY
The hose you want is Trident 144 HD Bilge and Baitwell hose. https://shop.sailboatowners.com/prod.php?7975

Most bilge pumps can only push water not air, so once the bilge is dry they can not push water out of the hose and it will drain back into the bilge. A diaphragm bilge pump will push the water out of the hose and out of the boat. They are expensive, Whale makes a nice one.

Some new bilge pumps have a check valve built into the pump. It is basically a rubber flap that keeps water from flowing back. Check valves in the hose have issues, like being stuck closed or open. If you have to install a check valve, try to install it somewhere accessible. Check valves are necessary if several pumps use the same through hull.

Before you replace your hose, look for a check valve in your system and clean it or replace it.
 
Aug 22, 2017
1,561
Hunter 26.5, 212, 170 West Palm Beach
The ribbed hose is designed to allow tighter bend radius without collapsing the diameter. If you want smooth bore hose, the "soda hose" that Home Depot carries, has worked well for me in the past. "soda hose" is the clear Vinyl hose with the strings in it.
 
Feb 8, 2014
1,080
Columbia 36 Muskegon
The ribbed hose is cheap and bends more easily. Downside is it slightly restricts flow and retains gunk, more likely to clog. As above, the reinforced or even unreinforced vinyl hose from the hardware store will work as well as the marine stuff. The unreinforced kind can tend to kink on bends, the kind with the fabric weave inside is stiffer.
 
Jun 14, 2010
844
Quorning Dragonfly 1200 home
@Capt jgw You can winterize without removing the check valve by sucking the last water out (from the outside) by holding a shop vac hose to the thru-hull fitting. Follow that by adding antifreeze to the bilge and do it again with antifreeze, sucking out the antifreeze (to remove any residual water).
 
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Apr 3, 2019
269
Macgregor 26M P Cub Boo Mobile AL
Steve,
You didn't mention hose size, flowrate, through-hull configuration, etc., such that a pressure loss due to corrugated hose could be checked. It can be significant, equal to adding another 5-6 ft of head to the pressure loss (using a 1-1/8" line and 9gpm -540gph). This reduces the pump flow rate according to your specific pump characteristics. A small flowrate in a big hose might not be an issue, while a big flowrate through a small hose would reduce flow significantly.

To your actual question; the pump will remove more water through a smooth bore tube than a corrugated one of equal inside diameter. The magnitude of that increase is dependent on the specific pump used and the pipe/fitting arrangement. Also, make sure your bilge is free of debris and trash. One old rag will do more to impede flow than any corrugated hose...

Also, running the correct size wire to the pump, to limit voltage drop, will help maximize flow rate.
 
Jun 4, 2009
3,146
Pearson 530 Admiralty Bay, Bequia SVG
Our bilge pump hose is corrugated and I suppose it doesn't do as good a job as a smooth hose, but I am absolutely guaranteed that there won't be any crimps somewhere out of sight in the run.
As for a check valve, they are absolutely not recommended in the discharge line of any submersible/centrifugal pump. A vented loop near the pump is about the best way to minimize run back, without changing pumps style or adding a smaller secondary pump in the deepest point of the bilge,
rule pump.png
 
Last edited:
Apr 3, 2019
269
Macgregor 26M P Cub Boo Mobile AL
Full disclosure: Mine is corrugated also for that same reason. My installation offered some routing challenges... Didn't want my sermon above to be mistaken for a diatribe on the evils of corrugated hose.
 
Apr 28, 2005
236
Oday 302 Lake Perry, KS
Thanks to all! As always, the helpful, experienced and smart people on this forum help out a fellow sailor.

I'm going to try to get to the boat this week to see if I can check out the hose and see if I do, indeed, have a leak. I suspect I do - and am thinking of just running all new hose if I can snake it through the engine compartment and pull it through the openings. The boat - and the hose - are 30 years old. Likely time for a new hose.
Thanks again to everyone - I get smarter every day when I get on this forum.
Steve
 
Jan 11, 2014
4,053
Sabre 362 113 Fair Haven, NY
One other quick thought. Make certain there are no sags in the hose. If the hose goes, then dips and goes up again, the pump will airlock and not pump the water out of the boat. It will then drain back to the pump and repeat.
 
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Apr 3, 2019
269
Macgregor 26M P Cub Boo Mobile AL
Excellent point, Dlochner. Nothing worse than installing a bilge pump and having the boat sink due to airlock. Short video for us visual learners
 
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Aug 22, 2017
1,561
Hunter 26.5, 212, 170 West Palm Beach
Somewhere I suspect I have a leak in my bilge pump hose (after the pump runs, the water returns). ...
I sometimes poke a small hole in my discharge hose, near it's highest point, to act as an anti-siphon vent. ABYC has something to say about needing a vent. I think that they also say something about the discharge being at least a foot above the water line. It's been a while since I read up on that stuff, so I'm a bit fuzzy on the details.