BUKH solutions on your LM
May 4, 2020 22:29:51 GMT
Post by Sula on May 4, 2020 22:29:51 GMT
You do not have to have another T part!
There are other solutions - see below.
That is a good point. My own thinking is that the T part should be put between the highest point of the exhaust hose and the hull outlet, so that any water that comes out goes into the sea and cannot fill back towards the engine, and when the engine is stopped, air can get into the system and break the water column between the seawater inlet and the water injection into the exhaust elbow so it cannot syphon. I think that even if the T piece is before the highest part there will usually be more exhaust gas that water in the pipe, and therefore it will operate OK, but it seems risky to me.
Solutions
I think the potential solutions you have come in two approaches. You can either
(1) replace your existing Y piece with an anti-syphon vent with a one-way valve (a Y piece with a valve that lets air in but not water out), e.g. Vetus AirventV www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves/vetus-antisiphon-device-airventv . With this approach you can throw away your T piece, and you do not need any small tubes or outlets, just the two main pipes from the engine and to the exhaust elbow injection point. (But I recommend you rinse the valve with water once a year, to stop any salt crystals naming the valve open and creating water leaks.)
or
(2) keep your existing Y piece, or replace i with another anti-syphon vent that does not have a valve (it is just a 3 way pipe connector), or buy another of that type, e.g. Vetus AirventH www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves/vetus-antisiphon-device-airventh . With this approach you need a small tube from the Y piece to somewhere the water can escape and air come in. This can be any of
(2a) into the exhaust, using your repaired T piece; or
(2b) outside the hull well above the waterline, direct into the sea; or
(2c) if you have a self-draining cockpit, into the cockpit (this has the advantage some like that you can see that the water is circulating when the engine is running).
My own preference would be for either solution (1) or solution (2b), but you have to decide for yourself.
Here are a range of anti-syphon vents (potential replacements for your 'Y' piece) of different types ns different manufacturers (make sure you buy one that is suitable for engine cooling - the cheapest ones are for toilet systems and may not be suitable for hot water). www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves Other suppliers are, of course, available.
Good luck!
There are other solutions - see below.
But need to say again, when I am thinking, even there is T and Y part, the water still can go to the exhaust/muffler while engine is at rest, right?
Solutions
I think the potential solutions you have come in two approaches. You can either
(1) replace your existing Y piece with an anti-syphon vent with a one-way valve (a Y piece with a valve that lets air in but not water out), e.g. Vetus AirventV www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves/vetus-antisiphon-device-airventv . With this approach you can throw away your T piece, and you do not need any small tubes or outlets, just the two main pipes from the engine and to the exhaust elbow injection point. (But I recommend you rinse the valve with water once a year, to stop any salt crystals naming the valve open and creating water leaks.)
or
(2) keep your existing Y piece, or replace i with another anti-syphon vent that does not have a valve (it is just a 3 way pipe connector), or buy another of that type, e.g. Vetus AirventH www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves/vetus-antisiphon-device-airventh . With this approach you need a small tube from the Y piece to somewhere the water can escape and air come in. This can be any of
(2a) into the exhaust, using your repaired T piece; or
(2b) outside the hull well above the waterline, direct into the sea; or
(2c) if you have a self-draining cockpit, into the cockpit (this has the advantage some like that you can see that the water is circulating when the engine is running).
My own preference would be for either solution (1) or solution (2b), but you have to decide for yourself.
Here are a range of anti-syphon vents (potential replacements for your 'Y' piece) of different types ns different manufacturers (make sure you buy one that is suitable for engine cooling - the cheapest ones are for toilet systems and may not be suitable for hot water). www.asap-supplies.com/fittings-valves-strainers/valves-spares/siphon-break-valves Other suppliers are, of course, available.
Good luck!