PSS Type C Shaft Seal
Image shown with flange.

PSS Type C Shaft Seal

For 6-1/2" to 8" (165mm to 203mm) shaft diameters

To receive a quote for a PSS Type C Shaft Seal, download and fill out the Quote Form below.

Quote Form

Unlike other PSS Shaft Seals, Type C has integrated support for the carbon stator so that it does not rely on the bellow for weight support. The PSS Type C Shaft Seal is available in three installation configurations:

  • Weld-on Stern Tube
  • Flange Mounted
  • Flange Mounted with Integrated Bladder System

As with all PSS seals, the PSS Type C model is a mechanical face seal using the flat surfaces of the rotating rotor and the stationary carbon flange and ring to create a water tight, dripless system. Commercial oriented by design, the Type C system uses a N50 rotor fitted on the shaft in front of the carbon flange and is secured in compression with a 316L split collar. The stationary acetal carbon stator is attached to a heavy duty silicone bellow clamped to the vessel using the appropriate mounting option.

Temperature Limits: -13°F to 425°F (-25°C to 220°C)
Working Pressure: Up to 25 PSI (1.75 BAR)
Max Pressure: 50 PSI (3.5 BAR)
Shaft RPM Limits: 1,500 RPM
Carbon Graphite: Lapped to 4 HLB (0.000044" tolerance)
316SS / Nitronic 50: Faced to 9 Ra
Bellow Material: Mandrel formed silicone / fabric

PSS Type C Shaft Seal Models

Weld on Stern Tube Model

This system features the standard PSS Type C Shaft Seal and is designed as a weld-on system for new construction and retrofit installations. Available in aluminum, steel, or 316L, this mounting system ensures minimal installation time, integrates with many vessel configurations, and eliminates the need for an additional adapter or bolt-on system.




How Does It Work?

How a PSS Type C Shaft Seal Works

1

This clamp assembly maintains the PSS Type C preload (compression) without the need for set screws.

2

Nitronic 50 SS rotor surfaced to 9-12 Ra finish.

3

Machined acetal hub with carbon stator insert, lapped to 4 HCB.

4

Water is fed into the PSS Shaft Seal for cooling and lubricating the seal faces on high speed vessels.

5

Stationary acetal/carbon stator clamped to the silicone bellow, which is attached to the stern tube (shaft log)

6

T-Bolt Type Hose clamps secure the bellow to the stern tube and to the acetal/carbon stator to the bellow.

7

Stern Tube made from your choice of aluminum, steel or 316L stainless steel, will be directly welded onto the vessel.




Dimensions

PSS Type C Seal Weld on Stern Tube Model dimensions
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-612-A 6.500" 10.982" 0.500" 10.938"
02-700-A 7.000" 10.982" 0.500" 10.938"
02-712-A 7.500" 10.982" 0.500" 10.938"
02-800-A 8.000" 10.982" 0.500" 10.938"
02-612-S 6.500" 10.982" 0.500" 10.938"
02-700-S 7.000" 10.982" 0.500" 10.938"
02-712-S 7.500" 10.982" 0.500" 10.938"
02-800-S 8.000" 10.982" 0.500" 10.938"
02-612-SS 6.500" 10.982" 0.500" 10.938"
02-700-SS 7.000" 10.982" 0.500" 10.938"
02-712-SS 7.500" 10.982" 0.500" 10.938"
02-800-SS 8.000" 10.982" 0.500" 10.938"
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-165M-A 6.500" 10.982" 0.500" 10.938"
02-178M-A 7.000" 10.982" 0.500" 10.938"
02-191M-A 7.500" 10.982" 0.500" 10.938"
02-203M-A 8.000" 10.982" 0.500" 10.938"
02-165M-S 6.500" 10.982" 0.500" 10.938"
02-178M-S 7.000" 10.982" 0.500" 10.938"
02-191M-S 7.500" 10.982" 0.500" 10.938"
02-203M-S 8.000" 10.982" 0.500" 10.938"
02-165M-SS 6.500" 10.982" 0.500" 10.938"
02-178M-SS 7.000" 10.982" 0.500" 10.938"
02-191M-SS 7.500" 10.982" 0.500" 10.938"
02-203M-SS 8.000" 10.982" 0.500" 10.938"



Components

PSS Type C Shaft Seal rotor

Rotor & Clamp Assembly

The Type C Shaft Seal rotor is manufactured out of Nitronic 50 stainless alloy machined to a 9-12 Ra finish on precision CNC lathes. It is secured on the shaft with a large locking collar placed in front of the rotor. This collar (clamp) has a dual purpose: It secures the rotor on the shaft and is used as a tool during installation. As on all the PSS seal families, the carbon stator further polishes the rotor during the initial hours of operations. The Nitronic 50 material is a very high grade of stainless steel, which is highly corrosion-resistant. Therefore, this rotor does not need replacement under normal operating conditions.

PSS Type C Shaft Seal carbon stator

Acetal Carbon Stator

Carbon-graphite is a versatile mechanical seal face material when used with mating rings of a harder material. The PSS carbon has superior wear characteristics and broad chemical resistance.

The high density, resin impregnated carbon ring is manufactured from a proprietary 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. The high density of the carbon greatly increases the longevity and wear resistance. During manufacturing, the carbon ring is seated in a metal hub. 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.

The PSS Type C acetal carbon stator is equipped with dual water injection ports for a positive water supply to be plumbed in.

PSS Type C Shaft Seal bellow

Bellows

The bellows on the Type C PSS Shaft Seal are constructed out of high temp silicone laminated with 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 in the polyester Aramid fabric. The 5 fabric inlay provides excellent strength to abrasion and resistance to pressure without loading the silicone.


PSS Type C Hose Clamps

Hose Clamps

The PSS Type C Shaft Seal uses T-Bolt style Hose Clamps to secure the bellow to the stern tube and the acetal carbon stator.

PSS Type C Shaft Seal hose barb

Hose Barb

A positive water supply is required to be plumbed to the PSS Shaft Seal to lubricate and cool 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.

PSS Type C Shaft Seal weld on stern tube

Stern Tube

On the Weld-on Stern Tube model of the PSS Type C Shaft Seal, the unit is provided to the customer with a metal tube that will need to be welded to the vessel. This metal is specified upon order by the customer. This tube is used to support the weight of the acetal carbon stator, so it stays centered to the shaft.

Flange Mounted Model

This system is ideal for retrofit or new construction installations; this system includes the standard Type C Seal and is designed as a bolt-on application. Available in aluminum, steel, or 316L, this mounting system is machined to match your specific application or existing flange pattern and is offered "pre-drilled" to your bolt pattern, size and spacing or supplied "blank" for simplicity and drilling at the time of installation.




How Does It Work?

How a PSS Type C Shaft Seal Works

1

This clamp assembly maintains the PSS Type C preload (compression.)

2

Nitronic 50 SS rotor surfaced to 9-12 Ra finish.

3

Machined acetal hub with carbon stator insert, lapped to 4 HCB.

4

Water is fed into the PSS Shaft Seal for cooling and lubricating the seal faces on high speed vessels.

5

T-Bolt style Hose clamps secure the bellow to the stern tube and to the acetal carbon stator to the bellow.

6

Stationary acetal/carbon stator clamped to the silicone bellow, which is attached to the stern tube (shaft log)

7

Flange made from your choice of aluminum, steel or 316L stainless steel.




Dimensions

PSS Type C Seal Flange Mounted model dimensions
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-612-AF 6.500" 10.982" 0.500" 10.938"
02-700-AF 7.000" 10.982" 0.500" 10.938"
02-712-AF 7.500" 10.982" 0.500" 10.938"
02-800-AF 8.000" 10.982" 0.500" 10.938"
02-612-SF 6.500" 10.982" 0.500" 10.938"
02-700-SF 7.000" 10.982" 0.500" 10.938"
02-712-SF 7.500" 10.982" 0.500" 10.938"
02-800-SF 8.000" 10.982" 0.500" 10.938"
02-612-SSF 6.500" 10.982" 0.500" 10.938"
02-700-SSF 7.000" 10.982" 0.500" 10.938"
02-712-SSF 7.500" 10.982" 0.500" 10.938"
02-800-SSF 8.000" 10.982" 0.500" 10.938"
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-165M-AF 6.500" 10.982" 0.500" 10.938"
02-178M-AF 7.000" 10.982" 0.500" 10.938"
02-191M-AF 7.500" 10.982" 0.500" 10.938"
02-203M-AF 8.000" 10.982" 0.500" 10.938"
02-165M-SF 6.500" 10.982" 0.500" 10.938"
02-178M-SF 7.000" 10.982" 0.500" 10.938"
02-191M-SF 7.500" 10.982" 0.500" 10.938"
02-203M-SF 8.000" 10.982" 0.500" 10.938"
02-165M-SSF 6.500" 10.982" 0.500" 10.938"
02-178M-SSF 7.000" 10.982" 0.500" 10.938"
02-191M-SSF 7.500" 10.982" 0.500" 10.938"
02-203M-SSF 8.000" 10.982" 0.500" 10.938"



Components

PSS Type C Shaft Seal rotor

Rotor & Clamp Assembly

The Type C Shaft Seal rotor is manufactured out of Nitronic 50 stainless alloy machined to a 9-12 Ra finish on precision CNC lathes. It is secured on the shaft with a large locking collar placed in front of the rotor. This collar (clamp) has a dual purpose: It secures the rotor on the shaft and is used as a tool during installation. As on all the PSS seal families, the carbon stator further polishes the rotor during the initial hours of operations. The Nitronic 50 material is a very high grade of stainless steel, which is almost highly corrosion resistant. Therefore, this rotor does not need replacement under normal operating conditions.

PSS Type C Shaft Seal carbon stator

Acetal Carbon Stator

Carbon-graphite is a versatile mechanical seal face material when used with mating rings of a harder material. The PSS carbon has superior wear characteristics and broad chemical resistance.

The high density, resin impregnated carbon ring is manufactured from a proprietary 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. The high density of the carbon greatly increases the longevity and wear resistance. During manufacturing, the carbon ring is seated in a metal hub. 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.

The PSS Type C acetal carbon stator is equipped with dual water injection ports for a positive water supply to be plumbed in.

PSS Type C Shaft Seal bellow

Bellows

The bellows on the Type C PSS Shaft Seal is constructed out of high temp silicone laminated with 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 5 fabric inlay provides excellent strength to abrasion and resistance to pressure without loading the silicone.


PSS Type C Hose Clamps

Hose Clamps

The PSS Type C Shaft Seal uses T-Bolt style Hose Clamps to secure the bellow to the stern tube and the acetal carbon stator.

PSS Type C Shaft Seal hose barb

Hose Barb

A positive water supply is required to be plumbed to the PSS Shaft Seal to lubricate and cool 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.

PSS Type C Shaft Seal weld on stern tube

Flange

Machined to match your specific application, the existing flange pattern is offered "pre-drilled" to your bolt pattern, size, spacing, or supplied "blank" for simplicity and drilling at the installation time.

Flange & Bladder Mounted Model

Also ideal for retrofit or new construction installations, this sytem includes the standard PSS Type C Shaft Seal and is designed as a bolt on application. Available in aluminum, steel or 316L, this mounting system is machined to match your specific application, existing flange pattern and is offered "pre-drilled" to your bolt pattern, size, spacing or supplied "blank" for simplicity and drilling at the time of installation.




How Does It Work?

How a PSS Type C Shaft Seal Works

1

This clamp assembly maintains the PSS Type C preload (compression).

2

Nitronic 50 SS rotor surfaced to 9-12 Ra finish.

3

Machined acetal hub with carbon stator insert, lapped to 4 HCB.

4

Water is fed into the PSS Shaft Seal for cooling/lubricating the seal faces on high speed vessels.

5

T-Bolt style Hose clamps secure the bellow to the stern tube and to the acetal/carbon stator to the bellow.

6

Stationary acetal carbon stator clamped to the silicone bellow, which is attached to the stern tube (shaft log)

7

Flange made from your choice of aluminum, steel or 316L stainless steel. Inflatable bladder allows the operator to seal the stern tube, while the shaft is not rotating, in order to inspect or clean the seal. In addition, if the uncoupling of the shaft is needed, this operation can be done in the water as the shaft can be moved aft with bladder inflated with no water intrusion occurring.




Dimensions

PSS Type C Seal Flange Bladder Mounted model dimensions
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-612-ABF 6.500" 10.982" 0.500" 10.938"
02-700-ABF 7.000" 10.982" 0.500" 10.938"
02-712-ABF 7.500" 10.982" 0.500" 10.938"
02-800-ABF 8.000" 10.982" 0.500" 10.938"
02-612-SBF 6.500" 10.982" 0.500" 10.938"
02-700-SBF 7.000" 10.982" 0.500" 10.938"
02-712-SBF 7.500" 10.982" 0.500" 10.938"
02-800-SBF 8.000" 10.982" 0.500" 10.938"
02-612-SSBF 6.500" 10.982" 0.500" 10.938"
02-700-SSBF 7.000" 10.982" 0.500" 10.938"
02-712-SSBF 7.500" 10.982" 0.500" 10.938"
02-800-SSBF 8.000" 10.982" 0.500" 10.938"
Part # Shaft Dia. (A) Uncompressed Length (B) Approx. Compression Rotor Diameter (C)
02-165M-ABF 6.500" 10.982" 0.500" 10.938"
02-178M-ABF 7.000" 10.982" 0.500" 10.938"
02-191M-ABF 7.500" 10.982" 0.500" 10.938"
02-203M-ABF 8.000" 10.982" 0.500" 10.938"
02-165M-SBF 6.500" 10.982" 0.500" 10.938"
02-178M-SBF 7.000" 10.982" 0.500" 10.938"
02-191M-SBF 7.500" 10.982" 0.500" 10.938"
02-203M-SBF 8.000" 10.982" 0.500" 10.938"
02-165M-SSBF 6.500" 10.982" 0.500" 10.938"
02-178M-SSBF 7.000" 10.982" 0.500" 10.938"
02-191M-SSBF 7.500" 10.982" 0.500" 10.938"
02-203M-SSBF 8.000" 10.982" 0.500" 10.938"



Components

PSS Type C Shaft Seal rotor

Rotor & Clamp Assembly

The Type C Shaft Seal rotor is manufactured out of Nitronic 50 stainless alloy machined to a 9-12 Ra finish on precision CNC lathes. It is secured on the shaft with a large locking collar placed in front of the rotor. This collar (clamp) has a dual purpose: It secures the rotor on the shaft and is used as a tool during installation. As on all the PSS seal families, the carbon stator further polishes the rotor during the initial hours of operations. The Nitronic 50 material is a very high grade of stainless steel, which is almost highly corrosion resistant. Therefore, this rotor does not need replacement under normal operating conditions.

PSS Type C Shaft Seal carbon stator

Acetal Carbon Stator

Carbon-graphite is a versatile mechanical seal face material when used with mating rings of a harder material. The PSS carbon has superior wear characteristics and broad chemical resistance.

The high density, resin impregnated carbon ring is manufactured from a proprietary 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. The high density of the carbon greatly increases the longevity and wear resistance. During manufacturing, the carbon ring is seated in a metal hub. 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.

The PSS Type C acetal carbon stator is equipped with dual water injection ports for a positive water supply to be plumbed in.

PSS Type C Shaft Seal bellow

Bellows

The bellows on the Type C PSS Shaft Seal is constructed out of high temp silicone laminated with 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 5 fabric inlay provides excellent strength to abrasion and resistance to pressure without loading the silicone.


PSS Type C Hose Clamps

Hose Clamps

The PSS Type C Shaft Seal uses T-Bolt style Hose Clamps to secure the bellow to the stern tube and the acetal carbon stator.

PSS Type C Shaft Seal hose barb

Hose Barb

A positive water supply is required to be plumbed to the PSS Shaft Seal to lubricate and cool 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.

PSS Type C Shaft Seal weld on stern tube

Flange & Bladder

Available in aluminum, steel, and 316L, this mounting system is machined to match your specific application, existing flange pattern, and is offered "pre-drilled" to your bolt pattern, size, spacing, or supplied "blank" for simplicity and drilling at the time of installation. The inflatable bladder option allows the operator to seal the stern tube while the shaft is not rotating to inspect or clean the seal. In addition, if the uncoupling of the shaft is needed, this operation can be done in the water as the shaft can be moved aft with bladder inflated with no water intrusion occurring. This inflatable bladder can also be used in case of an emergency.

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