随着液压传动和液压伺服系统的发展，生产实践中出现一些即要求能够连续的控制压力、流量和方向，又不需要其控制精度很高的液压系统。由于普通的液压元件不能满足具有一定的伺服性要求，而使用电液伺服阀又由于控制精度要求不高而过于浪费，因此近几年产生了介于普通液压元件（开关控制）和伺服阀（连续控制）之间的比例控制阀。电液比例控制阀（简称比例阀）实质上是一种廉价的、抗污染性能较好的电液控制阀。比例阀的发展经历两条途径，一是用比例电磁铁取代传统液压阀的手动调节输入机构，在传统液压阀的基础下：发展起来的各种比例方向、压力和流量阀；二是一些原电液伺服阀生产厂家在电液伺服阀的基础上，降低设计制造精度后发展起来的R9002442384WRA6WA30-22/G24N9K4/VR9005559674WRAE10W1-30-22/G24N9K31/A1VR9005583554WRAE6E30-22/G24N9K31/A1VR9005583564WRAE10E60-22/G24N9K31/A1VR9005757654WRA10W1-60-22/G24N9K4/VR9005774244WRA10W30-22/G24K4/VR9007105304WRAE10W60-22/G24K31/F1VR9007368944WRAE6W03-22/G24N9K31/A1VR9007507184WRAE6EA15-22/G24N9K31/A1VR9007620724WRAE6W30-22/G24K31/F1VR9007840244WRA6W1-15-22/G24N9K4/V-589R9007873744WRA6WA07-22/G24N9K4/V-589R9009009874WRAE6W30-22/G24N9K31/A1VR9009009884WRAE10W60-22/G24N9K31/A1VR9009020954WRA6W30-22/G24N9K4/VR9009020974WRA10E60-22/G24N9K4/VR9009025374WRA6W1-30-22/G24N9K4/VR9009029404WRA6E30-22/G24N9K4/VR9009040104WRAE10E30-22/G24N9K31/F1VR9009041054WRA6E07-22/G24N9K4/V-589R9009044384WRA6E15-22/G24K4/VR9009044394WRA6E30-22/G24K4/VR9009048014WRAE10WA60-22/G24N9K31/A1VR9009060344WRA6E1-15-22/G24N9K4/VR9009062624WRA6E07-22/G24N9K4/VR9009076504WRA10W60-22/G24N9K4/VR9009081954WRAE6W15-22/G24N9K31/F1VR9009082974WRA10E1-30-22/G24N9K4/VR9009082994WRA10W1-30-22/G24N9K4/VR9009089384WRAE6W15-22/G24N9K31/A1VR9009089784WRA10E1-60-22/G24N9K4/VR9009093894WRAE6E15-22/G24N9K31/A1VR9009096584WRAE10E1-60-22/G24N9K31/A1VR9009107804WRA6E07-22/G24K4/VR9009134424WRAE6W1-15-22/G24N9K31/A1VR9009134434WRA6W15-22/G24N9K4/VR9009134454WRAE6W1-30-22/G24N9K31/A1VR9009134464WRAEB6EA30-22/G24N9K31/A1VR9009136464WRAE10W30-22/G24N9K31/A1VR9009166014WRAE10EA60-22/G24N9K31/A1VR9009171934WRA10EA60-22/G24N9K4/VR9009200554WRAE10W60-22/G24N9K31/F1VR9009205574WRA6E15-22/G24N9K4/VR9009205884WRAE10E30-22/G24N9K31/A1VR9009212454WRA6E30-22/G24N9K4/V-589R9009217394WRA10E30-22/G24N9K4/VR9009224414WRA10W30-22/G24N9K4/V)