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Type 3 Roten and Uniten mechanical seal

The type 3 mechanical seal was first designed and patented by Roten seals in Italy in 1970. Its is one of the most common mechanical seal types in small water transfer and domestic pressure pumps. They are basic in design but very reliable seals and are a simpler pusher design with only a single rotational direction. The shaft seal uses a rubber O-ring shaft seal that seals in the pressure at the seal face end of the mechanism. A spring tensions the seal face against the stationary. The rotary face is commonly carbon graphite based but can also be available in silicone carbide and tungsten carbide. The stationary face is normally ceramic but can also come in silicone or tungsten carbide. They are generally only used for clean water due to the seal movement and using O-rings. They are also able to handle high operating pressures up to 1000kpa (10 Bar).

The “standard” type 3 seal is known as the Simplex or Roten type seal because its dimensions are based on the original Roten design. When the DIN EN 12756 standard was developed and accepted by all major pump and seal manufacturers, then a variation of the type 3 design was released called the Uniten. The Uniten seal generally has a slightly longer spring but a similar compressed length (L1) to a Roten Type 3. This allows the seal to provide slightly more compressive strength to the seal so it can handle higher pressures and more extreme operating conditions. We also have a couple of models of the Type 3K Uniten seal for certain applications again. These seals meet the DIN EN 12756 standard with L1 dimension meeting the L1K specification in the standard. We have a number of both Roten (Simplex) and Uniten type seals in stock at Rural Pumps in a number of common metric sizes to suit some popular pump brands like Lowara but can be ordered in up to 40mm, we have Type Uniten or Type 3 seals IN STOCK HERE in our webshop.

Operating Limits: Temperature: -30°~200°C  |  Pressure: ≤1 MPa  |  Speed: ≤15 m/s

Please contact us if you are looking for something unusual or use our pump selector in our webshop to get a replacement seal for your pump.