Two 2" Packless Sealing System Shaft Seals allowed us to eliminate the old traditional shaft seals which are a little more than rope and grease packed and compressed but constantly have a slow dripping leak.
PSS Type A Shaft Seal
For 3/4" to 3-3/4" (20mm to 95mm) shaft diameters
Product Specifications: PSS Type A Seal DimensionsDownloads: Installation Instructions
The Type A PSS Shaft Seal is a mechanical face seal. The sealing surface 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 front side of the bellows with hose clamps, and the back end of the bellows fits over the Stern tube and is secured with hose clamps. The stainless-steel rotor is fitted on the shaft in front of the carbon flange. The stainless-steel rotor compresses the bellows before the rotor is secured to the shaft with set screws. This compression (pre-load) maintains constant contact between the two flat faces of the stainless-steel rotor and carbon flange, allowing the PSS to compensate for the variable fore and aft movement due to propeller thrust. In addition, the carbon flange is over-bored to the shaft diameter allowing it to “float” around the shaft and thus compensate for most misalignment and vibration problems. The stainless-steel rotor is sealed to the shaft by two O-rings recessed into the collar's bore. These O-rings rotate with the shaft and stainless-steel rotor and do not experience wear during operation.
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)
316SS / Nitronic 50: 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 stainless steel rotor.
4. Water is fed into the PSS Shaft Seal for cooling/lubricating the seal faces on high speed vessels.
5. The stationary carbon stator is attached to the nitrile bellows, which is attached to the stern tube (shaft log).
COMPONENTS
Rotor
The rotor is made out of 316L stainless steel and machined to a 9-12Ra finish on precision CNC lathes. It is secured on the shaft using 2 pairs of set screws positioned at 90 degrees angle for maximum holding power. The stainless steel rotor further polishes the carbon stator during the initial hours of operations.
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 greatly increases longevity and wear resistance. As a result, several commercial vessels have recorded over 40,000 (over 4-1/2 years of continuous operation) engine hours on the same original components.
Bellows
The bellows on the Type A seal is molded out of a Nitrile compound. 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 simply 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.
|
Part # |
Shaft Dia. (A) |
Stern Tube Dia. (B) |
Uncompressed Length (C) |
Approx. Compression |
Rotor Diameter (D) |
Stern Cuff Length (E) |
|
3/4" |
1-1/4" to 1-3/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
3/4" |
1-1/2" to 1-5/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
3/4" |
1-3/4" to 1-7/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
3/4" |
2" to 2-1/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
3/4" |
2-1/4" to 2-3/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
3/4" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
1-1/4" to 1-3/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
1-1/2" to 1-5/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
1-3/4" to 1-7/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
2" to 2-1/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
2-1/4" to 2-3/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
7/8" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.375" |
1.5" |
|
|
1" |
1-1/4" to 1-3/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1" |
1-1/2" to 1-5/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1" |
1-3/4" to 1-7/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
1" |
2" to 2-1/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1" |
2-1/4" to 2-3/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
1" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
1-1/4" to 1-3/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
1-5/8" to 1-3/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
1-3/4" to 1-7/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
2" to 2-1/8" |
6.875" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
2-1/4" to 2-3/8" |
6.75" |
3/4" |
2.375" |
1.5" |
|
|
1-1/8" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.375" |
1.5" |
|
|
1-1/4" |
1-3/4" to 1-7/8" |
7.5" |
3/4" |
2.875" |
1.5" |
|
|
1-1/4" |
2" to 2-1/8" |
7.375" |
3/4" |
2.875" |
1.5" |
|
|
1-1/4" |
2-1/4" to 2-3/8" |
7.5" |
3/4" |
2.875" |
1.5" |
|
|
1-1/4" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.875" |
1.5" |
|
|
1-1/4" |
2-3/4" to 2-7/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-1/4" |
3" to 3-1/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-1/4" |
3-1/4" to 3-3/8" |
9.0625" |
3/4" |
2.875" |
2" |
|
|
1-1/4" |
3-1/2" to 3-5/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-3/8" |
1-3/4" to 1-7/8" |
7.5" |
3/4" |
2.875" |
1.5" |
|
|
1-3/8" |
2" to 2-1/8" |
7.375" |
3/4" |
2.875" |
1.5" |
|
|
1-3/8" |
2-1/4" to 2-3/8" |
7.5" |
3/4" |
2.875" |
1.5" |
|
|
1-3/8" |
2-1/2" to 2-5/8" |
7.375" |
3/4" |
2.875" |
1.5" |
|
|
1-3/8" |
2-3/4" to 2-7/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-3/8" |
3" to 3-1/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-3/8" |
3-1/4" to 3-3/8" |
9.063" |
3/4" |
2.875" |
2" |
|
|
1-3/8" |
3-1/2" to 3-5/8" |
8.875" |
3/4" |
2.875" |
2" |
|
|
1-1/2" |
2" to 2-1/8" |
9.155" |
1" |
3.75" |
2" |
|
|
1-1/2" |
2-1/4" to 2-3/8" |
9.155" |
1" |
3.75" |
2" |
|
|
1-1/2" |
2-1/2" to 2-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-1/2" |
2-3/4" to 2-7/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
1-1/2" |
3" to 3-1/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-1/2" |
3-1/4" to 3-3/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
1-1/2" |
3-1/2" to 3-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-1/2" |
3-3/4" to 3-7/8" |
9.405" |
1" |
3.75" |
2" |
|
|
1-1/2" |
4" to 4-1/8" |
9.405" |
1" |
3.75" |
2" |
|
|
1-3/4" |
2-1/4" to 2-3/8" |
9.155" |
1" |
3.75" |
2" |
|
|
1-3/4" |
2-1/2" to 2-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-3/4" |
2-3/4" to 2-7/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
1-3/4" |
3" to 3-1/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-3/4" |
3-1/4" to 3-3/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
1-3/4" |
3-1/2" to 3-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
1-3/4" |
3-3/4" to 3-7/8" |
9.405" |
1" |
3.75" |
2" |
|
|
1-3/4" |
4" to 4-1/8" |
9.405" |
1" |
3.75" |
2" |
|
|
2" |
2-1/2" to 2-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
2" |
2-3/4" to 2-7/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
2" |
3" to 3-1/8" |
9.03" |
1" |
3.75" |
2" |
|
|
2" |
3-1/4" to 3-3/8" |
9.2175" |
1" |
3.75" |
2" |
|
|
2" |
3-1/2" to 3-5/8" |
9.03" |
1" |
3.75" |
2" |
|
|
2" |
3-3/4" to 3-7/8" |
9.405" |
1" |
3.75" |
2" |
|
|
2" |
4" to 4-1/8" |
9.405" |
1" |
3.75" |
2" |
|
|
2-1/4" |
3-1/4" to 3-3/8" |
9.8125" |
1" |
4.2" |
2" |
|
|
2-1/4" |
3-1/2" to 3-5/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/4" |
3-3/4" to 3-7/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/4" |
4" to 4-1/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/4" |
4-1/4" to 4-3/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/4" |
4-1/2" to 4-5/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/4" |
4-3/4" to 4-7/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/4" |
5" to 5-1/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/2" |
3-1/4" to 3-3/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/2" |
3-1/2" to 3-5/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/2" |
3-3/4" to 3-7/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/2" |
4" to 4-1/8" |
9.625" |
1" |
4.2" |
2" |
|
|
2-1/2" |
4-1/4" to 4-3/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/2" |
4-1/2" to 4-5/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/2" |
4-3/4" to 4-7/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-1/2" |
5" to 5-1/8" |
10.25" |
1" |
4.2" |
2.5" |
|
|
2-3/4" |
4" to 4-1/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
2-3/4" |
4-1/4" to 4-3/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
2-3/4" |
4-1/2" to 4-5/8" |
10.125" |
1" |
5" |
2.5" |
|
|
2-3/4" |
4-3/4" to 4-7/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
2-3/4" |
5" to 5-1/8" |
10.125" |
1" |
5" |
2.5" |
|
|
2-3/4" |
5-1/4" to 5-3/8" |
10.25" |
1" |
5" |
2.5" |
|
|
2-3/4" |
5-1/2" to 5-5/8" |
10.25" |
1" |
5" |
2.5" |
|
|
2-3/4" |
5-3/4" to 5-7/8" |
10.25" |
1" |
5" |
2.5" |
|
|
2-3/4" |
6" to 6-1/8" |
10.25" |
1" |
5" |
2.5" |
|
|
3" |
4" to 4-1/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
3" |
4-1/4" to 4-3/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
3" |
4-1/2" to 4-5/8" |
10.125" |
1" |
5" |
2.5" |
|
|
3" |
4-3/4" to 4-7/8" |
10.3125" |
1" |
5" |
2.5" |
|
|
3" |
5" to 5-1/8" |
10.125" |
1" |
5" |
2.5" |
|
|
3" |
5-1/4" to 5-3/8" |
10.25" |
1" |
5.25" |
2.5" |
|
|
3" |
5-1/2" to 5-5/8" |
10.4375" |
1" |
5" |
2.5" |
|
|
3" |
5-3/4" to 5-7/8" |
10.25" |
1" |
5" |
2.5" |
|
|
3" |
6" to 6-1/8" |
10.25" |
1" |
5" |
2.5" |
|
|
3-1/4" |
4-1/2" to 4-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/4" |
4-3/4" to 4-7/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/4" |
5" to 5-1/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/4" |
5-1/4" to 5-3/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-1/4" |
5-1/2" to 5-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/4" |
5-3/4" to 5-7/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/4" |
6" to 6-1/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-1/4" |
6-1/4" to 6-3/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/4" |
6-1/2" to 6-5/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/4" |
6-3/4" to 6-7/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/4" |
7" to 7-1/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/2" |
4-1/2" to 4-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/2" |
4-3/4" to 4-7/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/2" |
5" to 5-1/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/2" |
5-1/4" to 5-3/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-1/2" |
5-1/2" to 5-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/2" |
5-3/4" to 5-7/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-1/2" |
6" to 6-1/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-1/2" |
6-1/4" to 6-3/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/2" |
6-1/2" to 6-5/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/2" |
6-3/4" to 6-7/8" |
11.675" |
1" |
6" |
2" |
|
|
3-1/2" |
7" to 7-1/8" |
11.675" |
1" |
6" |
2" |
|
|
3-5/8" |
4-1/2" to 4-5/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
4-3/4" to 4-7/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
5" to 5-1/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
5-1/4" to 5-3/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
5-1/2" to 5-5/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
5-3/4" to 5-7/8" |
10.86" |
1" |
6" |
2.5" |
|
|
3-5/8" |
6" to 6-1/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-5/8" |
6-1/4" to 6-3/8" |
11.675" |
1" |
6" |
2" |
|
|
3-5/8" |
6-1/2" to 6-5/8" |
11.675" |
1" |
6" |
2" |
|
|
3-5/8" |
6-3/4" to 6-7/8" |
11.675" |
1" |
6" |
2" |
|
|
3-5/8" |
7" to 7-1/8" |
11.675" |
1" |
6" |
2" |
|
|
3-3/4" |
4-1/2" to 4-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-3/4" |
4-3/4" to 4-7/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-3/4" |
5" to 5-1/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-3/4" |
5-1/4" to 5-3/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-3/4" |
5-1/2" to 5-5/8" |
10.8625" |
1" |
6" |
2.5" |
|
|
3-3/4" |
5-3/4" to 5-7/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-3/4" |
6" to 6-1/8" |
10.675" |
1" |
6" |
2.5" |
|
|
3-3/4" |
6-1/4" to 6-3/8" |
11.675" |
1" |
6" |
2" |
|
|
3-3/4" |
6-1/2" to 6-5/8" |
11.675" |
1" |
6" |
2" |
|
|
3-3/4" |
6-3/4" to 6-7/8" |
11.675" |
1" |
6" |
2" |
|
|
3-3/4" |
7" to 7-1/8" |
11.675" |
1" |
6" |
2" |
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.
Set Screws
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 or silicone hose below the waterline, the PSS bellows must be inspected regularly for any sign of wear, aging, or chemical deterioration. In addition, PYI recommends that the bellows be replaced once every 6 years. During the bellows replacement, it is also recommended that the o-rings and set screws in the stainless steel rotor be replaced and the hose clamps. PYI includes all of the necessary replacement parts in the PSS Maintenance Kit.
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.
