Patent ID: 6076259
Filing Date: 2000-06-20
Classification: F16K,Y10T

Abstract:
A method of removing or replacing a trunnion bearing of a rotary valve having a downstream side with a downstream connection and having an upstream side with an upstream connection to a high pressure penstock, the rotary valve comprising a valve rotor inside a valve body, the valve rotor having a trunnion within a trunnion bearing, said method comprising:(i) closing the valve;(ii) separating the valve from its downstream connection;(iii) offering up a support tool to the valve body to support the valve rotor on its downstream side;(iv) connecting a pressure-retaining closure tool to the valve body on the downstream side of the valve body and in so doing forming a space between the closure tool and the support tool;(v) pressurizing the space between the support tool and the pressure-retaining closure tool to balance a load due to a pressure at the upstream side acting on the valve rotor;(vi) adjusting the position of the support tool in order to support the valve rotor against the upstream load and to bring the rotor and its trunnion in a location enabling its bearing to be removed;(vii) securing the valve rotor in its bearing removal location by a mechanical locking structure;(viii) reducing the pressure in the space between the support tool and the pressure-retaining closure tool;(x) removing the trunnion bearing.