起重运输机器液压系统的高压软管通常是在变压力(脉动和振动压力)下工作的。这种工况是影响软管可靠性和寿命的主要因素。当采用滑阀或瓣阀时,软管里的工作压力可能超过安全阀调整压力的15～50%,而在运动质量急剧制动时,可能超过几倍。当增高的负荷作用时,软管的编织层在钢丝交叉的地方可能发生个别钢丝甚至整个软管的破坏。 High-pressure hoses for lifting and transporting machine hydraulic systems are usually operated under variable pressure (pulsation and vibration pressure). This condition is the main factor affecting hose reliability and longevity. When using a slide valve or flapper valve, the working pressure in the hose may exceed 15 to 50% of the relief valve adjustment pressure and may exceed several times in the event of a sharp braking of the sport mass. When an increased load is applied, the braid of the hose can break individual wires or even the entire hose where the wires cross.