THE WORLDS LEADING DRIPLESS SEAL – PSS SHAFT SEAL
PSS Shaft Seal is the number one alternative to packing gland seals. PSS is trusted by boat builders and yards all over the world. 100% water tight AND it saves wear. KG mechanical are proud to have been selected as a PSS Dealer, and to distribute this quality product . Call us on (07) 4033 7311 for more information or to place an order.
The PSS Shaft Seal is the number one selling marine mechanical seal worldwide and is installed as standard equipment by many of the world’s most reputable boat builders / yards. The PSS Shaft Seal is also recognized as the premier retrofit (aftermarket) seal on the world market. Certified by Bureau Veritas, ABS & Rina: Boat builders / yards recognize the advantages and value of installing the PSS as it eliminates the maintenance, constant adjustment & cost associated with traditional packing type glands. Aside from these benefits, the PSS Shaft Seal helps to eliminate water in the bilge (100% water tight) & wear to the propeller shaft. The PSS Shaft Seal can be easily retrofitted and is available for shafts ranging from 3/4″ (20mm) to 6″ (150mm).
The PSS Shaft Seal is a mechanical face seal that is created between the flat surfaces of the rotating stainless steel rotor and the stationary carbon flange. The stationary carbon flange is attached to the vessels stern tube with hose clamps and the carbon flange is attached to the front side of the bellows with hose clamps. The stainless steel rotor is fit on the shaft in front of the carbon flange. The stainless steel rotor is 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 steel 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 rotor and do not experience wear during operation.
PSS SHAFT SEALS: TYPE 1
Shaft Seals for shaft sizes 3/4″ – 3 3/4″ (20mm – 95mm).
PSS SHAFT SEALS: TYPE 2
Shaft Seals for shaft sizes 4″ – 6″ (100mm – 150mm).
MATERIALS REFERENCE FOR THE PSS SHAFT SEAL
1) HIGH DENSITY CARBON/GRAPHITE FLANGE
This space age composite is machined to shape. The face is then lapped to 4 light bands. Once installed and operational the carbon/graphite face will actually polish the stainless steel rotor face during the initial minutes of operation. This polishing process ensures a perfect seal and eliminates the necessity of a spray guard. The high density of this composite greatly increases its impact and wear resistance. At a maximum operating temperature of 500° F, the carbon guards against any overheating situation unlike other seals using plastic derivatives. The carbon/graphite flange should never need replacing under normal operation conditions.
2) DOUBLE O-RINGS
The nitrile O-Rings are fit inside the stainless steel rotor to guarantee alignment and seal of the rotor to propeller shaft. Nitrile is the material used due to its superior resistance to petroleum products, temperature variations and resistance to tearing. These O-rings are stationary and do not wear.
3) STAINLESS STEEL ROTOR
The one-piece stainless steel (Type 316) rotor is slid down and secured to the propeller shaft with double set screws. Precision tolerance are maintained by computer controlled lathes. After machining, the rotors are passivized to military specifications for maximum corrosion resistance. The stainless steel rotor should never need replacing under normal operating conditions.
4) DOUBLE ALLEN HEAD SET SCREWS
Allen head set screws with cupped ends (to prevent damage to shaft) are threaded into the rotor and secured to the propeller shaft. A second set screw is then threaded into each hole to secure the first screw and to prevent it from possibly backing out. Set screws are treated with a Dri-Loc 204.
5) DOUBLE HOSE CLAMPS
Two stainless steel hose clamps are used to secure the bellow at both the stern tube and flange ends.
Bellow is resistance to petroleum based products and set retention. It provides the best combination of durability, strength and elasticity. The stern tube end of the bellow is available in 1/4″ increments. Both shaft and stern tube diameters are necessary when ordering.