We were recently asked by a large North Island Hydro Generator to find a solution for leaking wicket gate glands on an aging turbine. On inspection we found that the wicket gate shafts were badly pitted with rust oysters and the journals had 2mm radial movement meaning the traditional gland packing leaked excessively even after regular tightening to the point that no further adjustment was possible.
As this turbine was not due for overhaul for another 5 years this leakage had to somehow be brought under control. We recommended the use of Chesterton 1730SC (silicon core) braided packing as bull (end) rings to assist with the radial movement and the stuffing box to be filled with Chesterton CMS2000 Injectable Pump Sealant, an environmentally friendly seal known to operate with zero to minimal leakage, thus keeping river water out of the turbine pit. With the work of Bradley, a very capable engineer, the client was able to remove all the old gland packing, clean the stuffing box and repack with the Chesterton 1730SC/CMS2000 solution without dismantling any equipment other than the gland follower.
The result has impressed even the critics, and this has led to a second machine being scheduled to repack with Chesterton. The secret of the low leakage is the unique internal laminar shear which creates a tortured path to restrict leakage through the packing, not along the shaft. This technology can also be used on large pumps with worn/pitted stuffing boxes such as in the water and waste water industry and pulp and paper. Packing the gland is easy with direct injection of the CMS2000 into the stuffing box via a standard grease nipple, which allows for remote adjustments.
If this sounds too good to be true, contact Craig on 0274323594 or Graham 021323595 and we will send you further information.