PSS PRO Shaft Seal 2-3/4" Shaft & 4" Tube 03-234-400

PRO Shaft Seal 2-3/4" Shaft & 4" Tube

The PSS PRO Shaft Seal is a mechanical face seal utilizing PSS Shaft Seal's proven stainless steel and carbon sealing components but adding reinforced silicone bellows, a secondary shaft retention collar, 316 stainless steel hose clamps (rolled edges and 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 suitable for various applications with unmatched performance.

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 bellows 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 bellows. 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. 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 from the drive line. The stainless-steel rotor is sealed to the shaft by two O-rings recessed into the rotor's bore. These O-rings rotate with the shaft and the stainless-steel rotor and therefore do not experience wear during operation.

Components:

Shaft Retention Collar

The PYI Shaft Retention Collar is designed to help retain the propeller or rudder shaft in a vessel in the event of catastrophic failure of the coupling or if the shaft comes free from the coupling. The double-split design provides maximum axial holding power with quick and efficient assembly with the shaft installed. The design fully engages the shaft without marring. Easily installed where major disassembly would otherwise be required. Greater axial holding power than set screws 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 9–12Ra finish on precision CNC lathes. It is secured on the shaft using 2 pairs of set screws positioned at a 90-degree 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 stainless steel rotor further polishes the carbon stator 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, 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, unlike a lip seal or a plastic face seal. In addition, the high density of the carbon 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.

Bellows

The bellows on both the PRO and Type B PSS seals are constructed out of high-temperature 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 bellows are sealed so no water can get into 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 using stainless steel hoops laid into the convolutions of the bellows.

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 lubricating and cooling the seal faces. There are many water supply sources; review the PSS Shaft Seal Installation Instructions for more information and note that all plumbing must follow the standards and practices of proper boat plumbing. In most cases, a slow-speed boat with no bearing in 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 to ensure the vent hose is never below the water line, even if the boat heels. Again, review the PSS Shaft Seal Installation Instructions for more details on venting the seal.

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

Product Dimensions:

• Shaft Diameter: 2-3/4"
• Stern Tube Diameter: 4" to 4-1/8"
• Uncompressed Length: 9.988"
• Approx. Compressed Length: 8.988"
• Rotor Diameter: 5"
• Stern Cuff Length: 1.3"

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

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Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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