With a reputation for manufacturing fine traditional stern gear, DH Porter & Company manufacture the following:
Stern tubes Stern bearing housings Flexible glands Stuffing boxes – fixed or stud type Oil seal glands
For low maintenance dripless shaft seal operation, DH Porter & Company are the NSW Stocking Distributor for the PSS (Packless Sealing System) Shaft Seal System.
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+ PSS Shaft Seal Brochure
The PSS shaft seal is a mechanical face seal. The seal is created between the flat surfaces of the rotating stainless steel collar, the stationary carbon flange and a rubber bellows.
The bellows is attached to the vessel stern tube (note: specify stern tube diameter when ordering) with hose clamps and the carbon flange is attached to the front side of the bellows with hose clamps. The stainless steel collar is fit on the shaft in front of the carbon flange. The stainless steel collar is then used to compress the bellows before the collar is secured to the shaft with set screws. This compression (pre-load) maintains contact between the faces and allows the PSS to compensate for the thrust from the propeller.
The carbon flange is bored larger than the shaft diameter, allowing it to 'float' around the shaft and thus compensate for most misalignment and vibration problems. The stainless collar is sealed to the shaft by two o-rings that are recessed into the bore of the collar. These o-rings rotate with the shaft and stainless steel collar and do not experience wear during operation.