Product Details
PRO Series Drive Shaft Seal by PSS Shaft Seal®. The PSS PRO Shaft Seal is a mechanical face seal utilizing the proven stainless steel and carbon sealing components, but adds a reinforced silicone bellow, PSS includes external rings standard on sizes +2-1/4" and optional on all smaller sizes, a secondary shaft retention collar, 316 Stainless Steel hose clamps (rolled edges & non-perforated) and an optional Nitronic 50 rotor upgrade (for highly corrosive environments). Designed specifically for applications that will require increased durability and resistance to harsh, corrosive, high pressure and otherwise demanding environments. The PSS PRO Shaft Seal is a specialized mechanical seal that is suitable for a variety of applications, with unmatched performance.
Specifications
| Temperature Limits: -13°F to 425°F (-25°C to 220°C) |
| Pressure Limits: 40 PSI (2.75 BAR) |
| Shaft RPM Limits: 10,000 RPM |
| Carbon Graphite: Lapped to 4 HLB (0.000044" tolerance) |
| 316SS / Nitronic 50: Faced to 9 Ra |
| Bellow Material: Molded formed silicone / fabric |
Features
- High quality at an affordable price
- Expertly made from premium materials
- Built to match your exact requirements
As with PSS Type A & B Seals, The PRO 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 a heavy duty silicone bellow which is attached to the vessel’s stern tube (shaft log), with 316SS hose clamps. The stainless-steel rotor is fitted on the shaft in front of the carbon flange and is used to compress the bellow , the rotor is then secured to the shaft with set-screws and the shaft retention collar is installed. This compression (pre-load) maintains constant contact between the two mating faces of the stainless-steel rotor and carbon flange, allowing the PSS to compensate for the variable axial movement due to propeller thrust. 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 from the drive-line. The stainless-steel rotor is sealed to the shaft by two O-rings that are recessed into the bore of the rotor. These O-rings rotate with the shaft and the stainless-steel rotor, and therefore do not experience wear during operation.
Shaft Retention Collar
The PYI Shaft Retention Collar is designed to help retain the propeller or rudder shaft in your vessel in the event of catastrophic failure of the coupling or if the shaft comes free from the coupling. The double split design provides the maximum in axial holding power with the benefit of quick and efficient assembly with the shaft installed. Design fully engages the shaft without marring. Easily installed where major disassembly would otherwise be required. Greater axial holding power than set screw or one-piece clamping collars. Effective on hard and soft shafts.
Rotor
The rotor on the PRO seal is manufactured out of 316L stainless steel and machined to a 9Ra finish on precision CNC lathes. It is secured on the shaft using 2 pairs of set screws positioned at 90 degrees angle in addition, a locking collar is placed in front of the rotor and further retains the propeller or rudder shaft in case of catastrophic failure of the coupling or if the shaft comes free from the coupling. As on the Type A seal the carbon stator further polishes the rotor during the initial hours of operations. This rotor does not need replacement under normal operating conditions.
Carbon Stator
The high density, resin impregnated carbon stator is manufactured from a space age composite which is first mixed and molded, 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. The high density of the carbon greatly increases the 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. The carbon should not need to be replaced under normal operating conditions.
Bellow
The bellow on both the PRO and Type B PSS seal is constructed out of high temp silicone laminated with either 4 or 5 plies of polyester fabric (aramid in larger sizes) and covered with a layer of fluorosilicone. In addition both ends of the bellow are sealed so no water can get in the polyester/Aramid fabric. The 4 or 5 fabric inlay provides excellent strength to abrasion and resistance to pressure without loading the silicone. On the larger models, the strength is greatly increased by the use of stainless steel hoops laid into the convolutions of the bellow.
Hose Barb
For high speed vessels (planning hulls or vessels powering over 12 knots) it is required that a positive water supply be plumbed to the PSS Shaft Seal for the purpose of lubricating and cooling the seal faces. There are many sources of water supply, review the PSS Shaft Seal Installation Instructions for more information and note all plumbing must follow the standards and practices of proper boat plumbing. In most cases a slow speed boat that does not have a bearing in 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 water line and as close to the center line as possible to ensure the vent hose is never below the water line, even if the boat heels. Review the PSS Shaft Seal Installation Instructions for more details on venting the seal.
Bellow Rings
Stainless steel rings are fit to the bellow for increased strength, support and durability. External rings come standard on sizes 2-1/4" (60mm) to 3-3/4" (95mm) and optional for smaller sizes.