| Stuffing Box:
PYI Packless Sealing System - PSS#02-138-212 |
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| Botany Bay's stuffing box is
under the engine due to the V-Drive configuration of her transmission.
This leaves barely enough room to get a hand between the engine and the
hull for access to the stuffing box. In fact, to service the stuffing
box or coupling it is generally easier to remove the V-Drive from the
transmission (with transmission oil going everywhere) than work on it in
place!
So, after several seasons of fighting with the stuffing box trying to
keep the adjustment just right (i.e. it drips slightly while motoring
but does not while sitting still) I gave up and went to one of the drip
less sealing systems. I chose the PYI Packless Sealing system (P.S.S.)
which is based upon a stainless donut around the shaft pressing against
a carbon flange and bellows connected to the stern tube. The specific
model I used on Botany Bay is: Many individuals have expressed concern about failure of the bellows and the resultant ingress of water when far away from haul out facilities. In the case of the CAL Cruising 35 the cutless bearing is in the end of the stern tube and significantly limits the amount of water which flows around the shaft. In fact, I installed the P.S.S. in the water (with the V-Drive removed) and the single 6 GPM bilge pump easily kept up with the flow when the stuffing box was completely removed. It is now 2003 and I will replace the bellows assembly after 17,000 miles of offshore sailing and approximately 2500 hours of engine operation since installing the system in 1997. My normal shaft RPM is approximately 1000 due to a 2.5:1 reduction gear in the transmission. Now my bilges are dry and I have to add water occasionally to check on the bilge pumps. PYI strongly recommends that if the vessel has a water injected stern tube that their fitting be used as opposed to a fitting on the stern tube. The reason is that if the water injection loop ingests air and it rises up to the carbon on steel seal it could damage it. Injecting the water at the carbon flange avoids this problem. The only reason I have considered using the port on the stern tube is to avoid having to tweak the position of the hose feeding the water injection port to keep side loads off the flange. The installation of a new bellows was trivial, the carbon graphite flange has a distinct ridge to provide an indication of how the bellows should be installed. The outside diameter of Botany Bay's stern tube increases from the 2.5" smooth diameter to something larger where additional fiberglass reinforcement was used. If there had been room I would have pressed the old bellows down over the stern tube thus providing an ever present backup to the primary bellows. Too bad there was not room, I only needed a couple of more inches! |
PYI Dripless packing system..
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