I believe I may have found an aswer. The yacht toilets never worked properly; always stiff and jerky often with poor water quantity. A couple of weeks back we removed toilets fully with a plan in desperation to rebore the cylinder and put in a plastic cylinder liner but that wasn't possible, so we rebuilt again as was.
When we removed the toilets the water flowed from the supply pipe but I didn't take much count. I then spent dozens of hours figuring how to make the pump redundant by spring cock valves but retain the old pump for its looks. I could not find anything to handle salt water
and spatial limitations. But these toilets have been working for 100 years so I went back to try and find the problem, and tried this forum.
After the replies, it then occurred to me that one common element in the system is the inlet flush salt water
, which enters the hull
about 1 mtr below water and flows directly to both toilets ....... and the water runs freely. The total system is below water level. Why do we need a pump when the free water runs faster than the pump? I was onto something, so I went to a diving
web site and with their calculations established we had likely 15 - 20 psi at the pump inlet. The secret and the problem all along is that the supply inlet pressure is too great for the pump to work
In researching the toilet owner's manual to try and see where a pressure-reducing valve could fit, I noticed a midget note that says if the toilet is well below water level, there is an optional extra heavy valve available for the inlet to the pump. I immediately ordered them from UK and await delivery
. I am positive I have found the problem after 3 years, but what a chase!
Incidentally, Hurrica V I believe won her first race
on 22 March, and turned 90 on March 24! What a present.