CarlF said "I have never seen (or witnessed) a high quality hose properly double clamped to a seacock fail at anchor
. Even if it were to happen, lives are not put at risk."
I have - well sort of - the sordid details follow!
I installed a Spectra watermaker
system on our boat in spring 2000. The connections to the seawater suction lines on both 3.8 GPM feed pumps were very high quality hose and stainless steel
double hose clamps.
In the fall of 2003 I made an overnight run from Bahia
San Francisquito to Santa Rosalita on the central east coast
of the Baja California
Peninsula. I ran the Spectra watermaker
for five hours during the sail south.
In retrospect, I should have been curious why our one-quarter full 85 gallon water tank did not fill up when the 16 GPH Spectra system was feeding it for five hours.
After I docked at Santa Rosalia I did get curious.
I eventually discovered that one of the two feed pump
hoses had come loose on the discharge side. The feed pumps are in a compartment below the waterline that is plumbed to the bilge
to carry away any overflow or seepage.
It turned out I had been pumping 3.8 GPM of saltwater into the bilge for five hours and only pumping 7 GPH of freshwater into the tank.
The STAINLESS hose clamps were both rusted, rotten, and had broken.
I checked the STAINLESS clamps with a magnet and found that the "made in China" clamps were not stainless and were magnetic.
I then checked everyone of the other 30 STAINLESS STEEL
hose clamps in the Spectra System and found that almost (not quite all) ALL of them were cheap
ferrous clamps. Many of those 30 were on the verge of rusting thru and breaking off and several of the clamps had in fact broken but the hose had not yet come off.
I keep all my boat expense receipts and was able to verify that I had paid top dollar at WEST Marine for stainless hose clamps and had in fact received cheap
I then checked dozens of other hose clamps on the boat and found about half of them were also magnetic and not good stainless.
I know cheap clamps are an old story but sometimes even the best effort to avoid them is not sufficient.
I SHOULD HAVE checked each clamp with a magnet BEFORE I installed them.
Ever since then, I check every clamp I buy with a magnet before I pay for them.