PSS Ceramic Shaft Seal
For 2-3/4" to 5" (70mm to 127mm) shaft diameters
Get a QuoteProduct Specifications: PSS Ceramic Seal Dimensions
Downloads: Installation Instructions
The PSS Ceramic Shaft Seal is available across all current PSS models (Type A, PRO & B) and is a solution-driven option specifically targeting applications potentially affected by or producing elevated levels of electrical current. The non-conductive sealing face eliminates the flow of the potential electric current, thus removing the risk of damaging electrolysis to the sealing face.
As with all PSS Shaft Seal Mechanical face seals, the sealing surface is created between the flat surfaces of the rotating stainless-steel ceramic rotor and the stationary carbon flange. The stationary carbon flange is secured to the front side of the bellows with a pair of hose clamps, while the back end of the bellows fits over the vessel stern tube and is also secured with a pair of hose clamps. The rotor fits on the shaft in front of the carbon flange and compresses the bellows before being secured to the shaft with set-screws. This compression (pre-load) maintains constant contact between the two flat surfaces of the ceramic face and carbon flange, allowing the PSS to compensate for the shaft's variable fore and aft movement due to propeller thrust. The carbon flange is over-bored to the shaft diameter, allowing it to “float” around the shaft, thus compensating for most shaft misalignment and vibration problems (within reason). The stainless-steel ceramic rotor is sealed to the shaft by two O-rings recessed into the collar's bore. As these O-rings rotate with the shaft and rotor; they do not experience any wear during operation.
Available for shaft sizes 2-3/4” to 5" (70mm to 127mm) as a complete seal or retrofittable upgrade with a simple rotor replacement.
Temperature Limits: 5°F to 225°F (-15°C to 107°C)
Pressure Limits: 15 PSI (1 BAR)
Shaft RPM Limits: 10,000 RPM
Carbon Graphite: Lapped to 4 HLB (0.000044" tolerance)
Ceramic: Faced to 9-12 Ra
Bellows Material: Molded Nitrile - PVC
How Does It Work?
1
Two nitrile o-rings seal the stainless steel rotor to the shaft and will not experience wear.
2
A primary set screw and a backup set screw (2 sets) are used to secure the stainless steel rotor to the shaft.
3
A seal is created between the two flat surfaces of the carbon stator and the ceramic/stainless steel rotor.
4
Water is fed into the PSS Shaft Seal for cooling and lubricating the seal faces on high-speed vessels.
5
The stationary carbon stator is attached to the nitrile bellows, attached to the stern tube (shaft log).
Components
Rotor
The ceramic carrier is manufactured out of 316L stainless steel and precision machined to accept a ceramic disc. The ceramic sealing face is machined and lapped to a 9-12Ra finish and secured to the carrier, resulting in a non-conductive sealing face that insulates the rotor from potentially harmful electrical current flow. The rotor is then secured on the shaft using 2 pairs of set screws positioned at a 90-degree angle for maximum holding power. The ceramic disc further polishes the carbon stator face during the initial hours of operation.
Carbon Stator
The high density, resin impregnated carbon stator is manufactured from an advanced composite that is first mixed and molded and then formed under pressure. The blank parts are then baked, machined, and lapped to a measured flatness of 4 helium light bands (measured at 0.000044" of variation over its entire lapped surface). The grade of carbon composite used in the PSS Shaft Seal has a maximum operating temperature of 500°F (+260°C) and cannot melt if the seal runs dry for a short period of time, unlike a lip seal or a plastic face seal. In addition, the high density of the carbon stator greatly increases longevity and wear resistance. Several commercial vessels have recorded over 40,000 (over 4-1/2 years of continuous operation) engine hours on the same original components. Therefore, the carbon should not need to be replaced under normal operating conditions.
Bellows
The bellows on the PSS Ceramic Shaft Seal is available in two materials, nitrile and silicone. Nitrile is known for its good resistance to petroleum products. In addition, it provides the best combination of durability, strength, and elasticity necessary in this application.
Hose Barb
For high-speed vessels (12+ knots), a positive water supply is required to be plumbed to the PSS Shaft Seal for lubricating and cooling the seal faces. Please review the PSS Shaft Seal Installation Instructions for more information on pickup points for water supply. In most cases, a slow-speed boat (less than 12 knots) that does not have a bearing the shaft log does not require positive water feed and can be vented. Ideally, the vent line will be run at least 2-3 feet above the waterline and as close to the centerline as possible. This will ensure the vent hose is never below the water line, even with significant heeling. PSS Shaft Seal Installation Instructions have more details on venting the seal.
Dimensions
| Part # | Shaft Dia. (A) | Stern Tube Dia. (B) | Uncompressed Length (C) | Approx. Compression | Rotor Diameter (D) | Stern Cuff Length (E) |
|---|---|---|---|---|---|---|
| 02-234-400CER | 2-3/4" | 4" to 4-1/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-234-414CER | 2-3/4" | 4-1/4" to 4-3/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-234-412CER | 2-3/4" | 4-1/2" to 4-5/8" | 10.125" | 1" | 5" | 2.5" |
| 02-234-434CER | 2-3/4" | 4-3/4" to 4-7/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-234-500CER | 2-3/4" | 5" to 5-1/8" | 10.125" | 1" | 5" | 2.5" |
| 02-234-514CER | 2-3/4" | 5-1/4" to 5-3/8" | 10.25" | 1" | 5" | 2.5" |
| 02-234-512CER | 2-3/4" | 5-1/2" to 5-5/8" | 10.25" | 1" | 5" | 2.5" |
| 02-234-534CER | 2-3/4" | 5-3/4" to 5-7/8" | 10.25" | 1" | 5" | 2.5" |
| 02-234-600CER | 2-3/4" | 6" to 6-1/8" | 10.25" | 1" | 5" | 2.5" |
| 02-300-400CER | 3" | 4" to 4-1/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-300-414CER | 3" | 4-1/4" to 4-3/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-300-412CER | 3" | 4-1/2" to 4-5/8" | 10.125" | 1" | 5" | 2.5" |
| 02-300-434CER | 3" | 4-3/4" to 4-7/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-300-500CER | 3" | 5" to 5-1/8" | 10.125" | 1" | 5" | 2.5" |
| 02-300-514CER | 3" | 5-1/4" to 5-3/8" | 10.25" | 1" | 5.25" | 2.5" |
| 02-300-512CER | 3" | 5-1/2" to 5-5/8" | 10.4375" | 1" | 5" | 2.5" |
| 02-300-534CER | 3" | 5-3/4" to 5-7/8" | 10.25" | 1" | 5" | 2.5" |
| 02-300-600CER | 3" | 6" to 6-1/8" | 10.25" | 1" | 5" | 2.5" |
| 02-314-412CER | 3-1/4" | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-314-434CER | 3-1/4" | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-314-500CER | 3-1/4" | 5" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-314-514CER | 3-1/4" | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-314-512CER | 3-1/4" | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-314-534CER | 3-1/4" | 5-3/4" to 5-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-314-600CER | 3-1/4" | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-314-614CER | 3-1/4" | 6-1/4" to 6-3/8" | 11.675" | 1" | 6" | 2" |
| 02-314-612CER | 3-1/4" | 6-1/2" to 6-5/8" | 11.675" | 1" | 6" | 2" |
| 02-314-634CER | 3-1/4" | 6-3/4" to 6-7/8" | 11.675" | 1" | 6" | 2" |
| 02-314-700CER | 3-1/4" | 7" to 7-1/8" | 11.675" | 1" | 6" | 2" |
| 02-312-412CER | 3-1/2" | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-312-434CER | 3-1/2" | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-312-500CER | 3-1/2" | 5" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-312-514CER | 3-1/2" | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-312-512CER | 3-1/2" | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-312-534CER | 3-1/2" | 5-3/4" to 5-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-312-600CER | 3-1/2" | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-312-614CER | 3-1/2" | 6-1/4" to 6-3/8" | 11.675" | 1" | 6" | 2" |
| 02-312-612CER | 3-1/2" | 6-1/2" to 6-5/8" | 11.675" | 1" | 6" | 2" |
| 02-312-634CER | 3-1/2" | 6-3/4" to 6-7/8" | 11.675" | 1" | 6" | 2" |
| 02-312-700CER | 3-1/2" | 7" to 7-1/8" | 11.675" | 1" | 6" | 2" |
| 02-358-412CER | 3-5/8" | 4-1/2" to 4-5/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-434CER | 3-5/8" | 4-3/4" to 4-7/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-500CER | 3-5/8" | 5" to 5-1/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-514CER | 3-5/8" | 5-1/4" to 5-3/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-512CER | 3-5/8" | 5-1/2" to 5-5/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-534CER | 3-5/8" | 5-3/4" to 5-7/8" | 10.86" | 1" | 6" | 2.5" |
| 02-358-600CER | 3-5/8" | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-358-614CER | 3-5/8" | 6-1/4" to 6-3/8" | 11.675" | 1" | 6" | 2" |
| 02-358-612CER | 3-5/8" | 6-1/2" to 6-5/8" | 11.675" | 1" | 6" | 2" |
| 02-358-634CER | 3-5/8" | 6-3/4" to 6-7/8" | 11.675" | 1" | 6" | 2" |
| 02-358-700CER | 3-5/8" | 7" to 7-1/8" | 11.675" | 1" | 6" | 2" |
| 02-334-412CER | 3-3/4" | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-334-434CER | 3-3/4" | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-334-500CER | 3-3/4" | 5" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-334-514CER | 3-3/4" | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-334-512CER | 3-3/4" | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-334-534CER | 3-3/4" | 5-3/4" to 5-7/8" | 10.675" | 1" | 6" | 2.5" |
| 02-334-600CER | 3-3/4" | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-334-614CER | 3-3/4" | 6-1/4" to 6-3/8" | 11.675" | 1" | 6" | 2" |
| 02-334-612CER | 3-3/4" | 6-1/2" to 6-5/8" | 11.675" | 1" | 6" | 2" |
| 02-334-634CER | 3-3/4" | 6-3/4" to 6-7/8" | 11.675" | 1" | 6" | 2" |
| 02-334-700CER | 3-3/4" | 7" to 7-1/8" | 11.675" | 1" | 6" | 2" |
| Part # | Shaft Dia. (A) | Stern Tube Dia. (B) | Approx. Length (C) | Approx. Compression | Rotor Diameter (D) | Stern Cuff Length (E) |
|---|---|---|---|---|---|---|
| 02-60M-314CER | 60mm | 3-1/4" to 3-3/8" | 9.625" | 1" | 4.2" | 2" |
| 02-60M-312CER | 60mm | 3-1/2" to 3-5/8" | 9.625" | 1" | 4.2" | 2" |
| 02-60M-334CER | 60mm | 3-3/4" to 3-7/8" | 9.625" | 1" | 4.2" | 2" |
| 02-60M-400CER | 60mm | 4" to 4-1/8" | 9.625" | 1" | 4.2" | 2" |
| 02-60M-414CER | 60mm | 4-1/4" to 4-3/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-60M-412CER | 60mm | 4-1/2" to 4-5/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-60M-434CER | 60mm | 4-3/4" to 4-7/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-60M-500CER | 60mm | 5" to 5-1/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-65M-314CER | 65mm | 3-1/4" to 3-3/8" | 9.625" | 1" | 4.2" | 2" |
| 02-65M-312CER | 65mm | 3-1/2" to 3-5/8" | 9.625" | 1" | 4.2" | 2" |
| 02-65M-334CER | 65mm | 3-3/4" to 3-7/8" | 9.625" | 1" | 4.2" | 2" |
| 02-65M-400CER | 65mm | 4" to 4-1/8" | 9.625" | 1" | 4.2" | 2" |
| 02-65M-414CER | 65mm | 4-1/4" to 4-3/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-65M-412CER | 65mm | 4-1/2" to 4-5/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-65M-434CER | 65mm | 4-3/4" to 4-7/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-65M-500CER | 65mm | 5" to 5-1/8" | 10.25" | 1" | 4.2" | 2.5" |
| 02-70M-400CER | 70mm | 4" to 4-1/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-70M-414CER | 70mm | 4-1/4" to 4-3/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-70M-412CER | 70mm | 4-1/2" to 4-5/8" | 10.125" | 1" | 5" | 2.5" |
| 02-70M-434CER | 70mm | 4-3/4" to 4-7/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-70M-500CER | 70mm | 5" to 5-1/8" | 10.125" | 1" | 5" | 2.5" |
| 02-70M-514CER | 70mm | 5-1/4" to 5-3/8" | 10.25" | 1" | 5" | 2.5" |
| 02-70M-512CER | 70mm | 5-1/2" to 5-5/8" | 10.25" | 1" | 5" | 2.5" |
| 02-70M-534CER | 70mm | 5-3/4" to 5-7/8" | 10.25" | 1" | 5" | 2.5" |
| 02-70M-600CER | 70mm | 6" to 6-1/8" | 10.25" | 1" | 5" | 2.5" |
| 02-75M-400CER | 75mm | 4" to 4-1/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-75M-414CER | 75mm | 4-1/4" to 4-3/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-75M-412CER | 75mm | 4-1/2" to 4-5/8" | 10.125" | 1" | 5" | 2.5" |
| 02-75M-434CER | 75mm | 4-3/4" to 4-7/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-75M-500CER | 75mm | 5" to 5-1/8" | 10.125" | 1" | 5" | 2.5" |
| 02-75M-514CER | 75mm | 5-1/4" to 5-3/8" | 10.25" | 1" | 5" | 2.5" |
| 02-75M-512CER | 75mm | 5-1/2" to 5-5/8" | 10.4375" | 1" | 5" | 2.5" |
| 02-75M-534CER | 75mm | 5-3/4" to 5-7/8" | 10.25" | 1" | 5" | 2.5" |
| 02-75M-600CER | 80mm | 6" to 6-1/8" | 10.25" | 1" | 5" | 2.5" |
| 02-80M-400CER | 80mm | 4" to 4-1/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-80M-414CER | 80mm | 4-1/4" to 4-3/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-80M-412CER | 80mm | 4-1/2" to 4-5/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-80M-434CER | 80mm | 4-3/4" to 4-7/8" | 10.3125" | 1" | 5" | 2.5" |
| 02-80M-500CER | 80mm | 5" to 5-1/8" | 10.125" | 1" | 5" | 2.5" |
| 02-80M-514CER | 80mm | 5-1/4" to 5-3/8" | 10.25" | 1" | 5" | 2.5" |
| 02-80M-512CER | 80mm | 5-1/2" to 5-5/8" | 10.4375" | 1" | 5" | 2.5" |
| 02-80M-534CER | 80mm | 5-3/4" to 5-7/8" | 10.25" | 1" | 5" | 2.5" |
| 02-80M-600CER | 80mm | 6" to 6-1/8" | 10.25" | 1" | 5" | 2.5" |
| 02-85M-415CER | 85mm | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-85M-434CER | 85mm | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-85M-500CER | 85mm | 5" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-85M-514CER | 85mm | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-85M-512CER | 85mm | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-85M-534CER | 85mm | 5-3/4" to 5-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-85M-600CER | 85mm | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-90M-412CER | 90mm | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-90M-434CER | 90mm | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-90M-500CER | 90mm | 5" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-90M-514CER | 90mm | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-90M-512CER | 90mm | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-90M-534CER | 90mm | 5-3/4" to 5-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-90M-600CER | 90mm | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
| 02-95M-412CER | 95mm | 4-1/2" to 4-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-95M-434CER | 95mm | 4-3/4" to 4-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-95M-500CER | 95mm | 5-1/8" to 5-1/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-95M-514CER | 95mm | 5-1/4" to 5-3/8" | 10.675" | 1" | 6" | 2.5" |
| 02-95M-512CER | 95mm | 5-1/2" to 5-5/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-95M-534CER | 95mm | 5-3/4" to 5-7/8" | 10.8625" | 1" | 6" | 2.5" |
| 02-95M-600CER | 95mm | 6" to 6-1/8" | 10.675" | 1" | 6" | 2.5" |
Tips
Here are some helpful tips to make sure you get the most out of your PSS Shaft Seal.
For more helpful tips please visit our FAQ page.
PSS Maintenance Kit
To ensure longevity and proper function of the PSS Shaft Seal, PYI provides a PSS Maintenance Kit to follow the PYI's recommended maintenance schedule. As with any rubber / silicone hose below waterline, the PSS bellows must be inspected on a regular basis for any sign of wear, aging or chemical deterioration. PYI recommends that the bellows be replaced once every 6 years. During the bellows replacement it is also recommended that the o-rings & set screws in the stainless steel rotor are replaced, as well as the hose clamps. PYI includes all of the necessary replacement parts in the PSS Maintenance Kit.
More Info
Set Screws
Please be sure to never use the same set screw on the shaft twice. There are two set screws in each of the two holes in the stainless steel rotor. One is tightened onto the shaft and the other is tightened onto the first to lock it in place against the shaft. The set screws are made with a cup at the base that compresses into the shaft ensuring a secure grip. When re-installing the rotor please use new set screws. In the case that you do not have spare set screws, the set screws in the rotor need to be reversed so there is an unused cup being compressed onto the shaft.
If you need to new set screws you can purchase a PSS O-Ring Kit. This comes with 2 new o-rings, 5 set screws, an allen wrench, Clamp Jackets and Thread Lock.
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