| How Does The PSS Mechanical Shaft Seal
Work? |
A mechanical seal is created by the contact
of a turning surface against a stationary surface. In the case of the PSS
Shaft Seal, the stationary surface is a carbon flange held in contact
against a stainless steel rotor which turns with the shaft. The carbon
flange is attached to the boat by a nitrile bellow which, with the help of
water pressure, produces a constant contact between the carbon and the
stainless steel ring. These type of seals are unaffected by engine motion or
vibrations. The result is a 100% watertight and totally maintenance-free
seal.
| What Makes The PSS Shaft
Seal Different & Why Is It Recognized As The Best On The Market? |
Warning!
All mechanical seals look very similar. There is, however, a
big difference in materials uses
in the components and subsequently in the way the seals will perform.
PSS SHAFT SEAL - SHOWN IN PLACE
ON VESSEL
(A)
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.
(B)
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.
(C)
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 passivated to military
specifications for maximum corrosion resistance. The stainless steel rotor
should never need replacing under normal operating conditions.
(D)
REINFORCED BELLOW
Reinforced 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.
(E)
DOUBLE HOSE CLAMPS
Two stainless steel hose
clamps are used to secure the bellow at both the stern tube and flange
ends.
(F)
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.
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