A system for grit blasting an annular junction portion of a pipeline extending along a longitudinal axis on board a laying vessel, comprises at least one carriage configured to advance along an annular path about the pipeline; at least one centrifugal turbine, which is configured to project grit towards the pipeline, rotates about a rotation axis lying on a plane orthogonal to the longitudinal axis and is supported by the carriage; at least one feed device configured to feed the grit to the centrifugal turbine and comprising a hopper which extends along a respective axis, defines a feed chamber and is coupled to the respective carriage and a guide device configured to act in conjunction with the hopper to feed the grit to the centrifugal turbine at all the operating positions of the carriage.

A system for grit blasting an annular junction portion of a pipeline extending along a longitudinal axis on board a laying vessel, comprises at least one carriage configured to advance along an annular path about the pipeline; at least one centrifugal turbine, which is configured to project grit towards the pipeline, rotates about a rotation axis lying on a plane orthogonal to the longitudinal axis and is supported by the carriage; at least one feed device configured to feed the grit to the centrifugal turbine and comprising a hopper which extends along a respective axis, defines a feed chamber and is coupled to the respective carriage and a guide device configured to act in conjunction with the hopper to feed the grit to the centrifugal turbine at all the operating positions of the carriage.

Provided is a water jet peening apparatus and a water jet peening method including: a clamping cylinder (201) which is able to be disposed at the outer peripheral side of an instrumentation nozzle (83) with a predetermined gap therebetween; a clamping piece (210) which is able to fix the clamping cylinder (201) to the instrumentation nozzle (83); a nozzle guide (221) which has a cylindrical shape, is provided inside the clamping cylinder (201), and is positioned to a position adjacent to the upper end of the instrumentation nozzle (83); an inner surface WJP nozzle (105) which is movable upward and downward inside the nozzle guide (221); and a drainage hole (224) which radially penetrates the nozzle guide (221). Accordingly, it is possible to improve the safety of the operation by preventing a thimble tube from being popped out due to a water jet peening operation.

A water jet peening apparatus includes: a nozzle, which is arranged in water and has a mouth from which water is jetted out; a detecting device, which is arranged in the water and detects sound in at least a part of a period during which the water is being jetted out from the mouth; and a processing device, which determines, based on a result of the detection by the detecting device, presence or absence of abnormality in the nozzle.

A sleeve may be configured to secure an airfoil cluster for polishing. The sleeve may include a mock airfoil and a bypass flow path between the mock airfoil and an end wall of the sleeve. The sleeve may be positioned in an annular ring of sleeves in a polishing apparatus. The polishing apparatus may comprise an annular flow path for an abrasive fluid. The abrasive fluid may be flowed through the annular ring of sleeves in order to polish the airfoil cluster.

A polishing method includes: a step of preparing a polishing device including a processing member and a suction mechanism configured to generate suction force; a step of setting a workpiece in the processing member; and a step of accelerating abrasive grains fed toward the workpiece to a predetermined speed with an air flow generated by operation of the suction mechanism, and polishing the workpiece by causing the abrasive grains to contact with or collide with the workpiece.

A method of prepping a cylindrical inner surface of a bore using a high-frequency forced pulsed waterjet apparatus entails generating a pressurized waterjet using a high-pressure water pump, generating a high-frequency signal using a high-frequency signal generator, applying the high-frequency signal to a transducer having a microtip to cause the microtip to vibrate to thereby generate the high-frequency forced pulsed waterjet, and rotating the rotatable ultrasonic nozzle inside the bore to prep the inner cylindrical surface of the bore using the high-frequency forced pulsed waterjets exiting from the angled exit orifices of the rotatable ultrasonic nozzle.

A method of prepping a cylindrical inner surface of a bore using a high-frequency forced pulsed waterjet apparatus entails generating a pressurized waterjet using a high-pressure water pump, generating a high-frequency signal using a high-frequency signal generator, applying the high-frequency signal to a transducer having a microtip to cause the microtip to vibrate to thereby generate the high-frequency forced pulsed waterjet, and rotating the rotatable ultrasonic nozzle inside the bore to prep the inner cylindrical surface of the bore using the high-frequency forced pulsed waterjets exiting from the angled exit orifices of the rotatable ultrasonic nozzle.

A masking system for a turbine including a first quantity of blades attached to a rotor and arranged adjacent one another to define a blade row with each blade including a blade root, includes a second quantity of center plates. Each center plate is disposed between two adjacent blades and includes a resilient member in contact with each of the two adjacent blades, and a first attachment member operable to attach the center plate to the rotor. The system includes a third quantity of side covers, each side cover positioned adjacent the blade root of one of the blades and connected to one of the center plates, each side cover including a resilient member positioned to surround a portion of the adjacent blade root, and a second attachment member operable to attach the side cover to the rotor.

A masking system for a turbine including a first quantity of blades attached to a rotor and arranged adjacent one another to define a blade row with each blade including a blade root, includes a second quantity of center plates. Each center plate is disposed between two adjacent blades and includes a resilient member in contact with each of the two adjacent blades, and a first attachment member operable to attach the center plate to the rotor. The system includes a third quantity of side covers, each side cover positioned adjacent the blade root of one of the blades and connected to one of the center plates, each side cover including a resilient member positioned to surround a portion of the adjacent blade root, and a second attachment member operable to attach the side cover to the rotor.