Confused by sanitation hose

DanTribe

DanTribe

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Help please.
I'm fitting a holding tank to a UFO 31 and need about 10m of 38mm sanitation hose.
Having read some previous posts on here I've become a bit confused.
One supplier sells "odour free hose, ideal for use in heads " £8.15/m
Same Supplier " Vetus hose, keeps smells at bay" £19.99/ m
or
Saniflex Premium Rubber hose £142 / 10m coil
or
ASAP butyl £20.26 / m
I have the usual problems of restricted access in the heads and needing to make a couple of tight bends.
Do I need to use the expensive stuff for all the runs including vents and pump out, which will have little contact with the honey?
I thought I knew what I needed, but the more I think the more confused I get.
 
I'm a big fan of the "Seaflow" butyl hose that ASAP sell (Seaflow seems to be their own-brand name, so you may well find the same stuff named differently elsewhere). Seems to be completely impermeable, and very easy to work with including making tight bends and getting it on and off fittings. As an additional recommendation, JFM over on the mobo forum demanded it specifically when Fairline were building his latest million-pound-plus baby superyacht, and he is a man well-known for researching the best possible option for every detail.

10m does sound like a hell of a lot though. You don't want to leave waste sitting in the hoses, so you need to pump enough water to flush it all the way through. For the standard Jabsco, the official figure is seven strokes per metre of hose. Seventy strokes after each use of the toilet is not going to happen, and if you did then you'd fill up the holding tank in short order. Can't it be mounted nearer?

Pete
 
prv said:
10m does sound like a hell of a lot though. You don't want to leave waste sitting in the hoses, so you need to pump enough water to flush it all the way through. For the standard Jabsco, the official figure is seven strokes per metre of hose. Seventy strokes after each use of the toilet is not going to happen, and if you did then you'd fill up the holding tank in short order. Can't it be mounted nearer?

Pete
Click to expand...
Thanks Pete.
To clarify, it's not 10m in one run.
I'm connecting the new tank to an existing Lavac and replacing the existing pipes at the same time.
Approx runs are:~
WC to seacock via pump 2.5m
WC to tank via diverter 1.5m
Tank to deck pump out 2.0m
Tank to seacock pump out 1.0m
Tank to deck vent 3.0m
All rounded up, so probably a bit less than this.
 
DanTribe said:
Thanks Pete.
To clarify, it's not 10m in one run.
I'm connecting the new tank to an existing Lavac and replacing the existing pipes at the same time.
Approx runs are:~
WC to seacock via pump 2.5m
WC to tank via diverter 1.5m
Tank to deck pump out 2.0m
Tank to seacock pump out 1.0m
Tank to deck vent 3.0m
All rounded up, so probably a bit less than this.
Click to expand...

The essential runs are the pump/diverter/tank/seacock as these are the ones that actually take sewage. The pumpout is unlikely to ever have any sewage resting in it, neither will the tank vent. Presumably the vent is 25mm whereas the others are 38mm.
 
Tranona said:
Presumably the vent is 25mm whereas the others are 38mm.
Click to expand...

Some installations do have 38mm vents, Kindred Spirit did (installed by Leesan I believe, before we had her). It's supposed to help keep the tank populated with aerobic bacteria rather than the smellier anaerobic ones.

Pete
 
prv said:
Some installations do have 38mm vents, Kindred Spirit did (installed by Leesan I believe, before we had her). It's supposed to help keep the tank populated with aerobic bacteria rather than the smellier anaerobic ones.

Pete
Click to expand...

Yes, the received wisdom is the bigger the better with 25mm minimum. Often the restriction is space to fit larger and running a 38mm vent in some situations would be problematic.
 
I don't know your local brands, but I've just spent 2 days in the close company of some Vetus SAHOSE38, and it's the mutznutz.
The best part is that you can get the best of those ratty little 1" offsets that seem to disturb your careful lineup. I can also say confidently that it bends round a 12" radius without kinking!
 
The Vetus pipe is worth having in all areas where the sewage may sit. It is also much more flexible than the white plastic looking hose.

I changed my pipes last year with this so called smell free white pipe, but its smelling again already. Pay the extra for the Vetus stuff.
 
Thanks for all your comments. I have bitten the bullet and am going for the Vetus mainly because I can get it locally.
The annoying thing is that after all my effort and expense people will just piss on my work.
 
I have the Vetus hose: my boat was pretty smelly when I bought it due to old sanitation pipe so I thought it was worth it and 5 years on it still isn't saying "replace me", so good result. Do be aware that it's ever-so-slightly slightly thicker than cheap hose and you may have to take a flapwheel to tight holes through shelves or bulkheads. Also do have a GOOD set of wireclippers to hand. The wire it's bound with is pretty tough, gave me strife when using a hacksaw trying to cut it straight, and resisted the cheap wirecutter I originally attacked it with.

Although I have no complaints about the performance of the Vetus hose I'm inclined to try the ASAP hose next time for comparison given the positive reports people have posted.
 
laika said:
Although I have no complaints about the performance of the Vetus hose I'm inclined to try the ASAP hose next time for comparison given the positive reports people have posted.
Click to expand...

I don't know the Vetus at all, but going by the description here it wouldn't surprise me if they were the identical stuff :)

Pete
 
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