Len wrote:
Peggie, could you elaborate a bit on the "solely for long strait
runs"-part. As you describe it, I suspect only a very few
installations are suited for using hard pvc.

You suspect correctly.

I installed hard pvc by using a heat gun and some 45 degree bends.
I made "the soft connection" on both ends and I used rubber fasteners
every 30-40 cm to ensure proper fixation and thus reliability.
In my view hard pvc (installed with care off course) is superior cause
it's really non-permeable and *stays* non-permeable. Next to that it's
a lot cheaper than these top-quality hoses.

It is indeed cheaper and non-permeable...but there are trade-offs--a LOT
more cemented inline fittings (cement can crack under stress, fittings
create "bumps" where waste and sea water minerals can get caught and
build up)...it gets very brittle below 40 F, which makes shock
absorption very important...and every "soft" connection is another
union. Attention to detail is VERY important when installing hard
pipe...'cuz any stress, even just pulling it a couple of inches to one
side, can result in a failed connection somewhere. Hose can just be
installed and pretty much ignored except for checking hose clamps
until/unless it starts to stink...but in some installations, hard pipe
can be more maintenance intensive than hose. About the only place I'd
put it in most boats under about 40' is the first section of pumpout
hose from a discharge at the bottom of the tank--a piece to the top of
the tank...'cuz that's the one section of hose in which waste must
always sit.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/detai...=400&group=327