试看20分钟大片视频

试看20分钟大片视频:Crown Block


试看20分钟大片视频:Features:

· The frame of the crown block is made of high strength steel shapes and plates.

· The sheave cluster is tilted to counteract traveling block's torque. The side plate assembly is facing derrick man so that it is easy to remove and suspend elevators.

· The sheave grooves are quenched with intermediate frequency so that the surface hardness is improved and the service life of sheaves is extended.

· Equipped with wooden bumper blocks and retainer net.

· The bearings and the sheaves are interchangeable with those of matching travelling block.

· The crown blocks are in accordance with API Spec. 4F, 8C.

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