VALVE BEARING REPLACEMENT

摘要

A method of removing or replacing a trunnion (4) bearing of a rotary valve connected to a high pressure penstock which comprises: closing the valve; separating the valve from its downstream connection; (iii) offering up a support means (23) to the valve body to support the valve rotor on its downstream side; connecting a pressure-retaining closure means (24) to the valve body; (v) pressurising the space (37) between the support means and the pressure-retaining closure means to balance the load on the valve rotor; adjusting the position of the support means in order to support the valve rotor against the upstream load; securing the valve rotor in its bearing removal location by mechanical locking means; (viii) reducing the pressure in the space (37) between the support means and the pressure-retaining closure means; optionally, repeating steps (v), (vi), (vii) and (viii) until the trunnion is substantially centrally positioned in its bearing; and (x) removing or replacing the trunnion bearing as required.