Vetus Anti Syphon on Heads - Help

VicS said:
Nothing is wrong with turning off the seacocks.
it when they are not turned off that the problems can occur.

I know a couple whose boat almost sank during the night while the family were all on board and asleep.
One of the children had used the toilet but had not properly closed one of the seacocks. It is very unlikely that vented loops would have been fitted.

Early the following morning when the owner woke their cool box floated past him. That was when he realised there was a problem.
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You are going off topic aren't you? We WERE talking about the wisdom (or otherwise) of deliberately fitting a device that introduces two adjacent 90deg bends, a constriction on the already barely adequate 38mm hose AND putting a source of potential air leakage when it cloggs, which it will.

Let me ask you one question:- When you get a toilet paper jam, where does it usually occur? At the outlet elbow from the pump, yes - because compacted toilet paper doesn't like going around sharp rt-angled bends?

Now you are wanting to introduce not just ONE extra such bend but TWO of the blighters right next to each other - asking for trouble. SWEEP bends are what you want in a toilet outlet. Read the instructions for a Saniflow - same situation.

Fine for a raw water inlet to an engine where you are just pumping fluids but this item as shown in the Vetus catalogue on p136 - also shown as an engine part elswhere in the catalogue is not suitable for semi-solids, IMO. Even in the engine application it needs to be vented outside of the hull - mine, a brass one, is connected to a dedicated fitting on the engine silencer. Before it was ,it just ran all over the engine and down into the engine tray when it leaked, which was often!

Chas
 
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My anti syphon loops are 135 degree sweep bends, certainly not 90 degree elbows!

Just introducing a high loop in the outlet and flush lines will not stop a syphon establishing. If anything the extra capacity in the line will help get it going.

That having been said my boat has survived 26 years without ANY anti-syphon loops.....the ones I have may be fitted this winter. Up till now turning the sea cocks off after every visit has worked fine.
 
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CharlesSwallow said:
You are going off topic aren't you? We WERE talking about the wisdom (or otherwise) of deliberately fitting a device that introduces two adjacent 90deg bends, a constriction on the already barely adequate 38mm hose AND putting a source of potential air leakage when it cloggs, which it will.

Let me ask you one question:- When you get a toilet paper jam, where does it usually occur? At the outlet elbow from the pump, yes - because compacted toilet paper doesn't like going around sharp rt-angled bends?

Now you are wanting to introduce not just ONE extra such bend but TWO of the blighters right next to each other - asking for trouble. SWEEP bends are what you want in a toilet outlet. Read the instructions for a Saniflow - same situation.

Fine for a raw water inlet to an engine where you are just pumping fluids but this item as shown in the Vetus catalogue on p136 - also shown as an engine part elswhere in the catalogue is not suitable for semi-solids, IMO. Even in the engine application it needs to be vented outside of the hull - mine, a brass one, is connected to a dedicated fitting on the engine silencer. Before it was ,it just ran all over the engine and down into the engine tray when it leaked, which was often!

Chas
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These "problems" do not occur if you use the proper vented loop as the OP is using. It is nothing like an engine antisyphon valve, not surprising as it fulfils an entirely different function.

Think all this confusion is because the original thread title had "Vetus" in it which is nothing to do with the vent in question.
 
If I may take this thread on a little bit.......

I intend to replace all of the inlet and outlet pipes for both heads on board. ( Old ones are now c 9 yrs old ) I have also purchased new vented loops. The air admittance valve can be screwed tighter or eased off. My question is, how do I know how much I am supposed to tighten the plastic nut up? :confused:
 
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