Raw water siphon loop?

[Eli27]

Sorry guys,,,, another question. Just about done with my 1979 albin 36 as far as engine maintenance goes. I've basically changed everything! Coolers, coolant and raw water hoses, updated raw water pump, t state with tank with expansion tank.

Anyways, while doing this I recently saw there was no siphon loop anywhere. Any idea if one is needed on this particular boat? There is a T fitting with a hose to the mixer that goes to the prop shaft bellows. Could that be used as a hose if placed properly?

Thanks

Eli

 

[koliver]

Sorry guys,,,, another question. Just about done with my 1979 albin 36 as far as engine maintenance goes. I've basically changed everything! Coolers, coolant and raw water hoses, updated raw water pump, t state with tank with expansion tank.

Anyways, while doing this I recently saw there was no siphon loop anywhere. Any idea if one is needed on this particular boat? There is a T fitting with a hose to the mixer that goes to the prop shaft bellows. Could that be used as a hose if placed properly?

Thanks

Eli

Not sure what you are asking.
None of the engine plumbing needs a siphon break. That is used where you are draining liquid to the outside, where the thru hull fitting is sometimes below the waterline, and where a reverse flow needs to be avoided. Bilge pumping arrangements usually qualify, so that there is no flow from the thru hull back into the bilge, when your thru hulls are submerged, and for head or holding tank discharges, so there is no reverse flow of waste back to the head or tank.
Your water line to the stuffing box or shaft bellows provides lubrication, so should be under pressure, created by your raw water pump. No chance of backflow in such a system, so no siphon break.
Your last question "Could that be used as a hose if placed properly?" does not really state what you are wanting to do, so I can't help there.

 

[Comodave]

I didn’t understand either.

 

[STB]

There is a T fitting with a hose to the mixer that goes to the prop shaft bellows. Could that be used as a hose if placed properly?

Hey Eli,

Any chance you can explain a buy more about what you'd like to use that t-fitting for and how a hose fits into the plan?

 

[psneeld]

From my readings on exhaust design (seems generator experts seem more concerned/better literature than I found on main engines...I think both Northern Lights and Westerbeke had some).... some engine placements and main exhaust placements can suffer if not a "high enough" loop or a siphon break loop is used.

My 40 Albin exhaust was debatable as to whether a backflow could occur because it didn't have a high enough loop, so the easy answer was use a Vetus siphon loop attached to the overhead of the engine room. This gave a pretty high loop and I used the one with the tube versus check valve. I placed the tiny through hull up along the overhead and straight out the hull side nearly below the after salon door. When I started the engine, a small water flow comes out the through hull and lets me know the seawater pump is working. So no need to walk aft to check the exhaust for flow.

I am not sure about your stuffing feed as an anti siphon as it depends on where it starts and finishes and where the rest of the engine components are versus the waterline. I wouldn't in general but may be possible.