What type of hose for bilge pump?

[BrianSmith]

Lots of threads on TF about bilge pumps, but I can't find any that deal with the specifics of the hose. I am upgrading from a 2200 gph pump to a 3700 gph, and adding a small (650 gph) pump to get all but about 1/3" of the water out. The 2200 used a 1" hose. The 3700 uses 1 1/2" and the 650 uses 3/4".

Nigel Calder says to avoid any hose that isn't smooth on the inside, as it can reduce flow by as much as 40%. But that leaves a LOT of hose available. Does anyone have any specific advice about what works well for bilge pumps? The run is about 21' with about a 3 1/2" rise to where they will enter the sea chest.

Thanks!

 

[HopCar]

Trident 147 or 148. Avoid the cheap thin wall stuff with molded in cuffs every two feet. Trident 120 is an example of the type to avoid.
Trident Marine Hose

 

[BrianSmith]

HopCar, thanks. I've been looking at those. Also, the Series 146 - in the pix, it looks pretty stout, but not sure about it in real life. Any experience with it? Thanks.
https://www.fisheriessupply.com/sierra-series-146-extra-duty-industrial-grade-pvc-vacuum-hose

 

[HopCar]

The 146 should be fine. Just avoid that really light stuff sold as bilge pump hose.

 

[High Wire]

Yes. Avoid the corrugated cheap "bilge pump" hose at all costs. It cracks open and leaks horribly in just a year or two.

 

[O C Diver]

I ended up using Trident white sanitation hose. Good results so far.

Ted

 

[BrianSmith]

I ended up using Trident white sanitation hose. Good results so far.

Ted

That's what's on the boat now, and it's just SO stiff! I guess there's nothing wrong with that, it just makes it a little tougher to work with on the initial installation.

 

[O C Diver]

That's what's on the boat now, and it's just SO stiff! I guess there's nothing wrong with that, it just makes it a little tougher to work with on the initial installation.

Heat is your friend. Very carefully I warmed the hose over a 2' section with a heat gun, and then made sweeping bends. Let the hose cool while maintaining the bend. When cool, the bend remains. If installing or removing the hose from fittings or bilge pumps, a little heat makes it very easy. PVC pipe hangers (available in the electrical section of Lowes and Home Depot) make great holding brackets.

Ted

 

[BrianSmith]

Heat is your friend. Very carefully I warmed the hose over a 2' section with a heat gun, and then made sweeping bends. Let the hose cool while maintaining the bend. When cool, the bend remains. If installing or removing the hose from fittings or bilge pumps, a little heat makes it very easy. PVC pipe hangers (available in the electrical section of Lowes and Home Depot) make great holding brackets.

Ted

I guess the heat from my butane cigar lighter wasn't enough. Should have gotten out the heat gun. (For putting a newly cut end onto a very tight hose barb.) Thanks for that "nudge".

 

[FF]

"and then made sweeping bends."

Great idea , any place a 90deg or any fitting can be discarded and a sweep used instead will up the GPH the pump will provide.

After you replace the pump and hose , measure the voltage with the pump running.

You might find another up grade to contemplate. Test with the battery charger Off.

 

[Riverguy]

The existing hose from the 2200GPH pump should work fine, you just need to rig up a way to fit it to your 3/4" output on the 650GPH.


I agree that using hose that is corrugated on the inside is not optimal (especially for 21' length), but what you are describing seems like a non-critical application, since the 3700GPH pump is there to handle anything more than a trickle.


Whether it's 3/4" or 1", 21 feet of hose is going to hold a lot of water, which will want to roll back downhill after the 650GPH shuts off, so think about a backflow check or some other means of keeping the water in the hose from running back into the bilge.

 

[psneeld]

To help with the long run, can you make a short uphill run followed by the long downhill run to the seachest to prevent too much backflow?

Most check valves are problems on various levels.

 

[BrianSmith]

My current setup in the bilge in the engine room is this: Rule 3700 with no one-way valve in the outlet / hose, operated by a float switch that won't start the pump unless the Whale 650 can't keep up. The Whale 650 does have a one-way valve (a duck valve kinda thing) in the outlet of the pump. So with just a little water, the 650 will come on and, in no great hurry, pump out all that it can, and keep it out. If it can't keep up. the 3700 will kick in. When the ingress stops, the 3700 will go until the float switch shuts it off, and then the water in its hose will backflow into the bilge, but the 650 will then evacuate as much as it can, and keep it out.

That's exactly what I'm planning to duplicate in the fwd bilge: a 3700 that comes on only if the 650 can't keep up, and a check valve in the 650 to allow it to get as much water as possible out of the bilge.

I'm in the process of installing a bilge pump monitor (with a microcontroller and Signal K) so I'll be alerted any time any of these pumps comes on, because both of my bilges should be dry all the time.

Finally, I want to install a water level sensor that will alert me (through the microcontroller / Signal K) to ANY water in either bilge, so I can investigate.

 

[HopCar]

Brian, that was just about the set up I used except I used the Jabsco copy of the Whale Pump.

 

[Ericdj]

Be careful with valleys and uphill/downhill runs. I can create an airlock.

See this Youtube video from Jabsco where they show what to avoid.
https://youtu.be/cweD5wJ6nh8

Regards,
Eric

 

[Steve DAntonio]

Lots of threads on TF about bilge pumps, but I can't find any that deal with the specifics of the hose. I am upgrading from a 2200 gph pump to a 3700 gph, and adding a small (650 gph) pump to get all but about 1/3" of the water out. The 2200 used a 1" hose. The 3700 uses 1 1/2" and the 650 uses 3/4".

Nigel Calder says to avoid any hose that isn't smooth on the inside, as it can reduce flow by as much as 40%. But that leaves a LOT of hose available. Does anyone have any specific advice about what works well for bilge pumps? The run is about 21' with about a 3 1/2" rise to where they will enter the sea chest.

Thanks!

It should be crush, and kink resistant, if it collapses when stepped on it's too delicate. This article includes a good example on page 53. http://stevedmarineconsulting.com/wp-content/uploads/2014/03/BilgePumps147_05.pdf Trident 144 and 147. You can use the white PVC sanitation hose, however, I agree it is stiff.

Make sure you have an anti-siphon loop, especially if it enters a sea chest.

 

[BrianSmith]

It should be crush, and kink resistant, if it collapses when stepped on it's too delicate. This article includes a good example on page 53. http://stevedmarineconsulting.com/wp-content/uploads/2014/03/BilgePumps147_05.pdf Trident 144 and 147. You can use the white PVC sanitation hose, however, I agree it is stiff.

Make sure you have an anti-siphon loop, especially if it enters a sea chest.

Steve, about that anti-siphon loop. All of my bilge pump hoses dump into the sea chest well above the waterline. It's not a sailboat, so there's no appreciable heeling to consider. You're not suggesting I need an anti-siphon loop in that situation, are you? Because it seems like the hose going up above the waterline and into the seachest IS the anti-siphon loop.

 

[sdowney717]

For a Rule 2000 I used 1.25" grey liquid-tight nonmetallic hose, it is basically grey pvc flexible conduit. This really boosted the pump outflow, earlier owner had used 3/4" rubber hose. This is a real tough flexible non crush-able hose,

For my two 3700 Rule pumps, I used a 1.5" pool vacuum suction cleaning hose.
It is actually flat wall on the inside, the ribs are flattened. These have been very durable over the last 5 years, no problems with either type hoses. Compared to the old rotten rubber hoses a previous owner had in there I am happy to have used what I had available without cost.

Original oem used small 3/4" rubber hoses with small pumps. Other owners upgraded pumps leaving the old hoses and they were so bad you could crack them by bending them. And had slid hoses onto hoses to get the pumps outlets to fit. Imagine clamping a rubber hose over another rubber hose. It does sort of work. But when you narrow the hose down, the pump cant possibly work to full capacity.

 

[Steve DAntonio]

Steve, about that anti-siphon loop. All of my bilge pump hoses dump into the sea chest well above the waterline. It's not a sailboat, so there's no appreciable heeling to consider. You're not suggesting I need an anti-siphon loop in that situation, are you? Because it seems like the hose going up above the waterline and into the seachest IS the anti-siphon loop.

Brian, there's a significant difference between siphoning and flooding. A rise in a discharge line prevents flooding, an anti-siphon loop prevents siphoning. All that's required for a siphon to occur is for the discharge to become submerged, and for the pump to be lower than the discharge, regardless of the height of the riser.

If your pumps discharge into the seachest, how far above the waterline can they be? My concern is an unusual scenario, and I've had this happen, a grounding for instance, where the normal waterline becomes submerged. If in such a case there's any chance of a pump discharge becoming submerged, an anti-siphon valve should be used. This article covers the subject https://www.proptalk.com/siphoning-vs-flooding

 

[ProMaritime]

I know of a great hose that comes in the sizes you mentioned. Good for everything buy potable water, fuel and exhaust. I've used it for twenty years. Very inexpensive compared to stuff they want to sell to yachties.

 

[Irish Rambler]

First A HAPPY, HEALTHY AND PROSPEROS NEW YEAR to everyone on TF.
I've read the comments avidly as our family business is transporting bulk liquids and powders. Just my tuppence worth from experience, smooth interior reinforced hose with gentle curves with a suitable pump of course for maximum flow rate.
'Borrow' the admirals hair dryer on high setting if you need to heat the pipe. Obviously wear heat resistant gloves as it can get uncomfortable holding the pipe while it cools down.
If you wish to put in a non return valve then use a swing gate flap check valve as it allows a better flow rate and for belt and braces approach make sure before fitting the nut and bolt holding the flap are burred over to prevent it working loose.
It also begs the question as to why there's water in the bilge in the first place, or are you just being cautious ?
I presume its only planning for the worst case scenario ?

 

[BrianSmith]

I know of a great hose that comes in the sizes you mentioned. Good for everything buy potable water, fuel and exhaust. I've used it for twenty years. Very inexpensive compared to stuff they want to sell to yachties.

Would you care to share this knowledge? It doesn't do me any good if it's only in your head.

 

[BrianSmith]

Brian, there's a significant difference between siphoning and flooding. A rise in a discharge line prevents flooding, an anti-siphon loop prevents siphoning. All that's required for a siphon to occur is for the discharge to become submerged, and for the pump to be lower than the discharge, regardless of the height of the riser.

If your pumps discharge into the seachest, how far above the waterline can they be? My concern is an unusual scenario, and I've had this happen, a grounding for instance, where the normal waterline becomes submerged. If in such a case there's any chance of a pump discharge becoming submerged, an anti-siphon valve should be used. This article covers the subject https://www.proptalk.com/siphoning-vs-flooding

Steve, thanks for the input. One of my main bilge pumps dumps into the sea chest about 14" above the waterline. I can't imagine this boat ever being 14" deeper in the water than normal, other than going up and down on waves, which would continually break any siphon. However, the other one dumps only about 5" above the waterline, which doesn't give me nearly the margin of safety I should probably have. There are a lot of inlets into the sea chest - I may need to look at swapping the lower bilge pump outlet to one of the higher sea chest inlets.

 

[BrianSmith]

<snip>...
It also begs the question as to why there's water in the bilge in the first place, or are you just being cautious ?
I presume its only planning for the worst case scenario ?

The bilges are usually dry. Except when I use the watermaker, and during a short part of the process, water dumps into one of the bilges. And except when I'm working on some plumbing system in the boat and I don't get a hose clamp fully tightened, and I pump 20 gallons into the bilge. Except when I overfill the fresh water tank and it overflows into the bilge. That kind of thing. The only outside water that has ever come into the bilges while we've owned the boat has been a very, very occasionaly drip from the dripless shaft seal. So no - in normal operation, I really don't need any bilge pumps at all!