| 摘要 |
PCT No. PCT/GB96/01456 Sec. 371 Date Aug. 7, 1998 Sec. 102(e) Date Aug. 7, 1998 PCT Filed Jun. 20, 1996 PCT Pub. No. WO97/01056 PCT Pub. Date Jan. 9, 1997A 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 including a valve rotor inside a valve body, the valve rotor having a trunnion within a trunnion bearing. The method includes the steps of closing the valve; separating the valve from its downstream connection; offering up a support tool to the valve body to support the valve rotor on its downstream side; 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; 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; 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; securing the valve rotor in its bearing removal location by a mechanical locking structure; reducing the pressure in the space between the support tool and the pressure-retaining closure tool; and removing the trunnion bearing. |
