国产一卡2卡3卡4卡无卡免费网站,yy111111电影院少妇影院无码,久久成人国产精品,丝袜高潮流白浆潮喷在线播放,色婷婷六月亚洲综合香蕉,男人天堂2018,40岁成熟女人牲交片,少妇裸体扒开两腿让我桶,美女视频免费看网站在线,欧美一区二区三区红桃小说

The trouble is that the drill pipe drops slowly after shutdown. The reason may be that the floating solenoid valve is stuck or the brake slips.

If the floating solenoid valve is stuck, the drill pipe may drop slowly even without stopping the machine. At this time, the floating solenoid valve can be disassembled, the spool can be disassembled and cleaned, or the valve can be replaced.

After long-term wear and tear of the brake pad, it will not provide enough braking force, which will cause braking failure and slow down of the drill pipe. At this time, the brake pad can be replaced.