Rotary Seals

Solosele® KB Hydro

Description
Solosele® KB Hydro is a profiled elastomeric seal specifically developed for the oscillating blade roots of Kaplan water turbines.

This seal 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.


Special features

  • Proves very cost effective.
  • Excellent sealing capability under fluctuating conditions.
  • Does not require adjustment to axial compressions to cater for offset caused by bearing wear.  
  • Works in a back-to-back arrangement to keep oil in and water out.
  • Efficiently seals shafts that run eccentrically on worn bearings.
  • Easy to retrofit using our special On-Site Joining (OSJ®) method - without removing the turbine blades.
  • Significantly reduces turbine downtime and maintenance costs..
  • Design is based on our highly successful Solosele® G single element hydraulic seal, widely renowned for its compact, robust construction and high integrity sealing under difficult mechanical conditions.

Applications
Solosele® KB Hydro has operated with great success for many years on the blade roots of Kaplan water turbines at hydroelectric schemes across the world - both as an OEM fit and as retrofit on older equipment. It has out-performed and run significantly longer than many multi-lip seals and other types at these sites. 

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 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
Solosele® KB Hydro does not need axial compression, therefore 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 retro-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 wanted a simple yet highly efficient seal that could 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 demanded a great skill in fitting to obtain effective results.

Materials of construction
We recommend our medium nitrile (NBR) elastomer for normal blade root sealing applications. This material has excellent resistance to all standard mineral oils used in the industry, 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 OEM assembly; or split seals with OSJ® kits for retrofitting. There is a range of radial sections to suit Kaplan blade root housings (see pdf of Solosele® KB Hydro leaflet, as offered below, for full details).

When specifying, please state James Walker Solosele® KB Hydro, and the following dimensions (in mm): 

  • Seal inside diameter (ie, shaft diameter).
  • Nominal housing section (ie, seal section).
  • Minimum housing depth (without spacers).
  • Also note any special considerations concerning your application (including requirement for Endless-type seals or OSJ®).

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.

 

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