Silicon Hose - use below waterline?

[neil1967]

I want to 'T' into a 38mm hose used as a cockpit drain (one of two). The new hose will be of substantially smaller diameter (13mm). The simplest solution would appear to be to use a silicon/polyester hose which can be bought relatively cheaply as a reducing 'T'. Would this be suitable for use below the waterline - the cockpit drain seacock would be left open most of the time we were aboard, but would be closed during any period of extended absence (the other cockpit drain would cope with rain water). I would attach the T directly to the seacock and then the existing end of the cockpit drain hose to the T with a joining piece. Thoughts?

Neil

 

[RichardS]

I would have thought that a silicone hose would be even better than the usual butyl rubber hoses but do need to be clipped on firmly as silicone is "slippier".

Richard

 

[lw395]

What will the small hose be attached to?
If you close that seacock, there may be some chance of rain/spray running up that hose, so it might need an antisiphon or stop valve or something?

The only problem I can see with the silicone hose would be if the other hose puts it under stress, the silicone is less stiff and might fold? Securing the other hose might prevent that.

 

[neil1967]

There will be a valve on the second (smaller) pipe as well.

 

[Spirit (of Glenans)]

There will be a valve on the second (smaller) pipe as well.

I had assumed that silicon hose was intended for the cooling systems in cars, i.e. specifically designed to contend with hot environments. Would'nt a more conventional material suffice?

 

[prof pat pending]

I had assumed that silicon hose was intended for the cooling systems in cars, i.e. specifically designed to contend with hot environments. Would'nt a more conventional material suffice?

Not really, it found a use there, but it’s also pretty good in cold temperatures, better than most in fact

 

[neil1967]

The ready availability of reducing 'T' pieces is what brought it to my attention - presumably it is relatively easy to mold more complex shapes in silicon tube than it is produce them in rubber. I'm sure the material is plenty strong enough (eg working/burst pressure) and I assume impervious to salt water, as it is, as noted, often used in car cooling systems with antifreeze.

 

[RichardS]

The ready availability of reducing 'T' pieces is what brought it to my attention - presumably it is relatively easy to mold more complex shapes in silicon tube than it is produce them in rubber. I'm sure the material is plenty strong enough (eg working/burst pressure) and I assume impervious to salt water, as it is, as noted, often used in car cooling systems with antifreeze.

I believe that silicone is more robust in every way than butyl/nitrile rubber but more expensive.

Richard