日本 DD51型内燃机车采用 KE14型旋转式制动阀,其阀座材质为铸铁,旋转阀材质为锡青铜。这种制动阀常常由于缺少滑油、生锈和进入灰尘、杂质等原因而发生泄漏和手柄卡住等故障。这样不但使检修工作大大增加,而且影响机车的正常运行。据后藤工厂1980～1983年的统计,在制动阀的故障中,因手柄阻力增加乃至卡住的占56%,制动阀泄漏的占 Japan DD51 type diesel locomotive using KE14-type rotary brake valve, the valve seat made of cast iron, rotary valve material is bronze. Such brake valve often due to lack of oil, rust and dust, impurities and other reasons, leakage and handle stuck and other failures. This will not only greatly increase maintenance work, but also affect the normal operation of the locomotive. According to the statistics of Goto Factory from 1980 to 1983, in the failure of the brake valve, 56% of the brake resistance increased and even stuck, accounting for the leakage of the brake valve