Berkeley S08019 Mechanical Shaft Seal - 5/8 in. Shaft
The Berkeley S08019 is the genuine mechanical shaft seal for pumps built on a 5/8 in. shaft, supplied in the Type 6 configuration with a cup-mounted stationary seat. It seals the one place in a centrifugal pump where a spinning component has to cross a pressure boundary: the point at which the shaft leaves the wet end and enters the bearing frame or motor. Everything else in the pump is sealed by static gaskets and o-rings; only this part has to hold back water while a shaft turns through it thousands of times a minute.
It manages that with two lapped faces held together by a spring. A ceramic stationary seat sits in a rubber cup in the seal housing and does not move. A carbon face rides on the shaft, carried on a Buna-N elastomer that both seals against the shaft and lets the face float, and a spring keeps it pressed against the ceramic as the faces slowly wear in. The two faces are polished flat to within a fraction of a wavelength of light, and in normal running they never touch metal to metal at all. They ride on a film of the pumped liquid only a few molecules thick, which lubricates and carries heat away. That is the whole reason a mechanical seal cannot survive running dry: take away the liquid and the carbon overheats, crazes and chips within seconds.
A tired seal announces itself. Water drips from the weep hole between the pump and the driver, there is a squeal for a few seconds at start-up, or you find rusty streaks below the joint. It is worth acting on quickly, because the water that gets past a failing seal goes straight toward the bearings, and a bearing failure takes the shaft and often the housing with it. When you fit the new one, keep the lapped faces spotless, handle both halves by their edges, and lubricate the rubber with clean water or a little soapy water only. Oil and grease swell Buna-N and will contaminate the faces before the pump has run a minute.
Key Features
- Genuine Berkeley (Pentair Pump Group) service part
- 5/8 in. shaft size, Type 6 design with a cup-mounted stationary seat
- Carbon rotating face against a ceramic stationary seat - a long-proven pairing for clean and raw water duty
- Buna-N elastomer seals to the shaft and allows the face to self-align
- Spring loaded, so face contact is maintained as the faces wear
- Complete two-piece seal supplied ready to fit
Applications
- Berkeley B-Series centrifugal pumps built with a mechanical seal
- Berkeley models C1-1/4TPMS, C2MPS and C1-1/2TPHS
- Replacing a seal that is dripping from the weep hole or squealing at start-up
- Scheduled wet-end overhaul and rebuild kits
- Freshwater, raw water, transfer and dewatering service
- Marine, dockside and shoreside installations
- Pump repair shops and service centres
Specifications
- Brand: Berkeley
- Manufacturer: Pentair Pump Group
- Manufacturer Part Number: S08019
- Part Type: Mechanical shaft seal
- Shaft Size: 5/8 in.
- Seal Type: Type 6, cup-mounted stationary seat
- Rotating Face: Carbon
- Stationary Seat: Ceramic
- Elastomer: Buna-N
- Quantity Used: One per pump
- Condition: New
Frequently Asked Questions
Q: Which way round do the two halves go?
The ceramic seat goes into the seal cavity first with its polished side facing outward toward the impeller. The carbon assembly then slides onto the shaft with its polished face meeting the ceramic. Fitted the wrong way round, both faces are destroyed on the first start.
Q: Is a small drip normal on a brand new seal?
A few drops over the first minutes while the faces bed in is common and usually stops on its own. A steady drip that persists past that, or one that returns after a day, means contamination, a damaged face or a fitting error rather than a seal that simply needs longer.
Q: Is Buna-N right for what I am pumping?
It handles water, seawater and many general-purpose fluids well, but it is not suited to every chemical or to high temperatures. If you are moving anything other than water, tell us the fluid and the operating temperature and we will check compatibility before you commit to it.
Q: Can I clean up and reuse a seal that has been apart?
No. Once the faces have separated, dust and fingerprints land on surfaces that need to be optically flat, and the carbon has already worn a matched pattern against its old seat. Mechanical seals are single-fit items, which is why they are replaced rather than serviced.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct shaft seal before you order.
CLRMarine
