Vetus holding tank venting

[stefan_r]

I am about to install a Vetus holding tank and see in the lovely diagram they provide that I can vent it through a filter and out...questions:

--what size pipe do I run from the tank up to the filter (I have choices from 16-38mm - the soil pipe is 38mm, surely the breather can be 16mm?!!)

--does the breather have to be located under the filter, I would like to have the filter next to the head to allow for easy changing of the element but also want to have the breather as high up as possible to prevent water ingress whle underway.

mailto: stefan@athito.com

 

[PaulJ]

Basically, the bigger the vent pipe the better and if you have room for a 38mm pipe then use that size. Have a look at www.boatbuilding.com and on the right-hand side of the home page click on "features". Amongst those features you will find "Marine Sanitation: Facts vs Folklore". This is an excellent article with just about all you could possibly want to know on the subject.

 

[Guest]

The breather outlet is below the filter to minimise the risk of the filter shipping water, which will damage it. The relevant British Standard (BS MA 101) recommends a 38mm bore vent pipe. The actual bore necessary will depend to an extent upon the type of toilet head and the type of tank, but the vent can never be too large. If the vent is too small or incorrectly installed you could implode a plastic holding tank if using a powerful shore pump-out installation. An undersize vent can also impair the efficiency of the flushing process.