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Description
Solosele® KB Hydro is a profiled elastomeric seal specifically developed for the oscillating blade roots of Kaplan water turbines. It is reinforced at the base with an integral anti-extrusion element of rubber-proofed fabric that is securely mould-bonded to the lip portion.
The anti-extrusion element is sufficiently tough to stop the seal from 'stretching and bunching' when the shaft rotates, yet is remarkably flexible for ease of fitting.
The very short axial length of this seal saves valuable housing space in new equipment. On older equipment with deeper housings, spacer rings can be supplied to move the sealing elements to unworn areas of the shaft.
We based the design of this seal on our highly successful Solosele® G single element hydraulic seal, that is widely renowned for its compact, robust construction and high integrity sealing under difficult mechanical conditions.
Special features
Applications
Solosele® KB Hydro has operated with great success for many years on the blade roots of Kaplan turbines at hydroelectric schemes across the world - both as original equipment fitments and as retrofit on older turbines.
In operation
A Solosele® KB Hydro sealing arrangement typically comprises two seals fitted back-to-back in the blade root housing. This keeps lubricant in the system and prevents the ingress of water and abrasive particles.
When the seal is installed in its housing, the radial squeeze on its elastomeric body provides low pressure sealing suitable for stationary and turbine start-up conditions. As system pressure rises, the seal responds accordingly to maintain constant sealing force under fluctuating and reversing pressure differentials (including negative pressure) between the oil and water.
In addition, the seal's highly developed profile enables it to overcome high levels of eccentricity or shaft offset caused by bearing wear at the blade root.
Installation
As Solosele® KB Hydro does not need axial compression, housing length tolerances can be relaxed and installation becomes a simple procedure. This is particularly valuable to turbine manufacturers when fitting endless-type seals during plant assembly.
On-Site Joining
Days of unnecessary turbine downtime and associated labour costs are saved when you fit Solosele® KB Hydro with On-Site Joining (OSJ).
Using our special OSJ technique, the split single-element Solosele® KB Hydro is efficiently joined to form an endless seal around the shaft. OSJ gives you the performance of a fully moulded seal with the maintenance benefits of a split seal - at best value price.
We have developed this technique to help customers who want a simple yet highly efficient seal that can be fitted swiftly and easily on site without removing the turbine blade. Before Solosele® KB Hydro + OSJ , the only answer was to use an expensive split multi-lip seal that demands great skill in fitting to obtain effective results.
Training for On-Site Joining
Successful application of Solosele® KB Hydro + OSJ relies on careful adherence to all stages of the joining process. This process is described step-by-step in the full fitting instructions supplied with each seal kit.
However, we recommend that first-time users attend one of our hands-on training sessions. These can be carried out on site, or at any of our premises worldwide.
Materials of construction
We recommend our medium nitrile (NBR) elastomer for normal blade root sealing applications. This material has excellent resistance to all types of oil and is suitable for the temperature ranges encountered by virtually all Kaplan water turbines.
How supplied
Solosele® KB Hydro is supplied as endless seals that are ideal for original equipment assembly; or split seals with OSJ (On-Site Joining) kits for retrofitting. There is a range of radial sections to suit Kaplan blade root housings (see pdf of leaflet, as offered below, for full details).
When specifying, please state James Walker Solosele® KB Hydro, and the following dimensions (in mm):
Then please contact your local James Walker company or distributor. They will provide the expert technical advice, and are more than willing to discuss the exact details of your application before you place an order.
Click here to download a pdf of the leaflet (370Kb)
Click here to download the Sealing Guide for the Hydropower Industry pdf (2.98MB)
