德国Rexroth力士乐直动式减压阀，力士乐DRHD/ZDRHD型减压阀，德国REXROTH力士乐减压阀是通过调节，将进口压力减至某一需要的出口压力，并依靠介质本身的能量，使出口压力自动保持稳定的阀门。从流体力学的观点看，REXROTH力士乐减压阀是一个局部阻力可以变化的节流元件，即通过改变节流面积，使流速及流体的动能改变，造成不同的压力损失，从而达到减压的目的。然后依靠控制与调节系统的调节，使阀后压力的波动与弹簧力相平衡，使阀后压力在一定的误差范围内保持恒定。
Rexroth直动式减压阀所示为直动式带溢流阀的减压阀（简称溢流减压阀）。
压力为P1的压缩空气，由左端输入经阀口节流后，压力降为P2输出。P2的大小可由调压弹簧进行调节。顺时针旋转旋钮，压缩弹簧及膜片使阀芯下移，增大阀口的开度使P2增大。若反时针旋转旋钮，阀口的开度减小，P2随之减小。
若P1瞬时升高，P2将随之升高，使膜片气室内压力升高，在膜片上产生的推力相应增大，此推力破坏了原来力的平衡，使膜片向上移动，有少部分气流经溢流孔、排气孔排出。在膜片上移的同时，因复位弹簧的作用，使阀芯8也向上移动，关小进气阀口，节流作用加大，使输出压力下降，直至达到新的平衡为止，输出压力基本又回到原来值。若输入压力瞬时下降，输出压力也下降、膜片下移，阀芯随之下移，进气阀口开大，节流作用减小，使输出压力也基本回到原来值。逆时针旋转旋钮。使调节弹簧放松，气体作用在膜片上的推力大于调压弹簧的作用力，膜片向上曲，靠复位弹簧的作用关闭进气阀口。再旋转旋钮，进气阀芯的顶端与溢流阀座4将脱开，膜片气室中的压缩空气便经溢流孔、排气孔11排出，使阀处于无输出状态。
力士乐直动式减压阀，Rexroth减压阀，力士乐DRHD/ZDRHD直动式减压阀
力士乐DRHD/ZDRHD直动式减压阀
规格6
安装面按DIN 24340 A型和ISO 4401
在各个单元中有夹紧压力调节和监控
夹紧和监控压力的共同调节
根据客户需要，可在内部或外部进行压力监控
小可调监测和/或次级压力的限制
力士乐DRHD/ZDRHD直动式减压阀型号有：
DRHD6DP1-4X/200-25K14 DRHD6DP1-4X/200-25XK14 DRHD6DP1-4X/200-50YK14
DRHD6DP1-4X/200-25YK14 DRHD6DP1-4X/200-50K14 DRHD6DP1-4X/200-50XK14
DRHD6DP1-4X/200-100K14 DRHD6DP1-4X/200-100XK14 DRHD6DP2-4X/200-100YK14
DRHD6DP1-4X/200-100YK14 DRHD6DP2-4X/200-25K14 DRHD6DP2-4X/200-25XK14
DRHD6DP2-4X/200-25YK14 DRHD6DP2-4X/200-50K14 DRHD6DP2-4X/200-50XK14
DRHD6DP2-4X/200-100K14 DRHD6DP2-4X/200-100XK14 DRHD6DP2-4X/200-50YK14
DRHD6DP3-4X/200-25YK14 DRHD6DP3-4X/200-50K14 DRHD6DP3-4X/200-50XK14
DRHD6DP3-4X/200-100K14 DRHD6DP3-4X/200-100XK14 DRHD6DP3-4X/200-50YK14
DRHD6DP3-4X/200-100YK14 DRHD6DA1-4X/200-25K14 DRHD6DA1-4X/200-25XK14
DRHD6DA1-4X/200-25YK14 DRHD6DA1-4X/200-50K14 DRHD6DA1-4X/200-50XK14
DRHD6DA1-4X/200-100K14 DRHD6DA1-4X/200-100XK14 DRHD6DA1-4X/200-50YK14
DRHD6DA1-4X/200-100YK14 DRHD6DA2-4X/200-25K14 DRHD6DA2-4X/200-25XK14
DRHD6DA2-4X/200-25YK14 DRHD6DA2-4X/200-50K14 DRHD6DA2-4X/200-50XK14
DRHD6DA2-4X/200-100K14 DRHD6DA2-4X/200-100XK14 DRHD6DA2-4X/200-100YK14
DRHD6DA3-4X/200-25K14 DRHD6DA3-4X/200-25XK14 DRHD6DA2-4X/200-50YK14
DRHD6DA3-4X/200-25YK14 DRHD6DA3-4X/200-50K14 DRHD6DA3-4X/200-50XK14
DRHD6DA3-4X/200-100K14 DRHD6DA3-4X/200-100XK14 DRHD6DA3-4X/200-50YK14
DRHD6DA3-4X/200-100YK14 DRHD6DB1-4X/200-25K14 DRHD6DB1-4X/200-25XK14
DRHD6DB1-4X/200-25YK14 DRHD6DB1-4X/200-50K14 DRHD6DB1-4X/200-50XK14
DRHD6DB1-4X/200-100K14 DRHD6DB1-4X/200-100XK14 DRHD6DB1-4X/200-50YK14
DRHD6DB1-4X/200-100YK14 DRHD6DB2-4X/200-25K14 DRHD6DB2-4X/200-25XK14
DRHD6DB2-4X/200-25YK14 DRHD6DB2-4X/200-50K14 DRHD6DB2-4X/200-50XK14
DRHD6DB2-4X/200-100K14 DRHD6DB2-4X/200-100XK14 DRHD6DB2-4X/200-100YK14
DRHD6DB3-4X/200-25K14 DRHD6DB3-4X/200-25XK14 DRHD6DB2-4X/200-50YK14
DRHD6DB3-4X/200-25YK14 DRHD6DB3-4X/200-50K14 DRHD6DB3-4X/200-50XK14
DRHD6DB3-4X/200-100K14 DRHD6DB3-4X/200-100XK14 DRHD6DB3-4X/200-50YK14
DRHD6DB3-4X/200-100YK14 ZDRHD6DP1-4X/200-25K14 ZDRHD6DP1-4X/200-25XK14
ZDRHD6DP1-4X/200-25YK14 ZDRHD6DP1-4X/200-50K14 ZDRHD6DP1-4X/200-50XK14
ZDRHD6DP1-4X/200-100K14 ZDRHD6DP1-4X/200-100XK14 ZDRHD6DP1-4X/200-50YK14
ZDRHD6DP1-4X/200-100YK14 ZDRHD6DP2-4X/200-25K14 ZDRHD6DP2-4X/200-25XK14
ZDRHD6DP2-4X/200-25YK14 ZDRHD6DP2-4X/200-50K14 ZDRHD6DP2-4X/200-50XK14
ZDRHD6DP2-4X/200-100K14 ZDRHD6DP2-4X/200-100XK14 ZDRHD6DP2-4X/200-100YK14
ZDRHD6DP3-4X/200-25K14 ZDRHD6DP3-4X/200-25XK14 ZDRHD6DP2-4X/200-50YK14
ZDRHD6DP3-4X/200-25YK14 ZDRHD6DP3-4X/200-50K14 ZDRHD6DP3-4X/200-50XK14
ZDRHD6DP3-4X/200-100K14 ZDRHD6DP3-4X/200-100XK14 ZDRHD6DP3-4X/200-50YK14
ZDRHD6DP3-4X/200-100YK14 ZDRHD6DA1-4X/200-25K14 ZDRHD6DA1-4X/200-25XK14
ZDRHD6DA1-4X/200-25YK14 ZDRHD6DA1-4X/200-50K14 ZDRHD6DA1-4X/200-50XK14
ZDRHD6DA1-4X/200-100K14 ZDRHD6DA1-4X/200-100XK14 ZDRHD6DA1-4X/200-50YK14
ZDRHD6DA1-4X/200-100YK14 ZDRHD6DA2-4X/200-25K14 ZDRHD6DA2-4X/200-25XK14
ZDRHD6DA2-4X/200-25YK14 ZDRHD6DA2-4X/200-50K14 ZDRHD6DA2-4X/200-50XK14
ZDRHD6DA2-4X/200-100K14 ZDRHD6DA2-4X/200-100XK14 ZDRHD6DA2-4X/200-100YK14
ZDRHD6DA3-4X/200-25K14 ZDRHD6DA3-4X/200-25XK14 ZDRHD6DA2-4X/200-50YK14
ZDRHD6DA3-4X/200-25YK14 ZDRHD6DA3-4X/200-50K14 ZDRHD6DA3-4X/200-50XK14
ZDRHD6DA3-4X/200-100K14 ZDRHD6DA3-4X/200-100XK14 ZDRHD6DA3-4X/200-50YK14
ZDRHD6DA3-4X/200-100YK14 ZDRHD6DB1-4X/200-25K14 ZDRHD6DB1-4X/200-25XK14
ZDRHD6DB1-4X/200-25YK14 ZDRHD6DB1-4X/200-50K14 ZDRHD6DB1-4X/200-50XK14
ZDRHD6DB1-4X/200-100K14 ZDRHD6DB1-4X/200-100XK14 ZDRHD6DB1-4X/200-50YK14
ZDRHD6DB1-4X/200-100YK14 ZDRHD6DB2-4X/200-25K14 ZDRHD6DB2-4X/200-25XK14
ZDRHD6DB2-4X/200-25YK14 ZDRHD6DB2-4X/200-50K14 ZDRHD6DB2-4X/200-50XK14
ZDRHD6DB2-4X/200-100K14 ZDRHD6DB2-4X/200-100XK14 ZDRHD6DB2-4X/200-100YK14
ZDRHD6DB3-4X/200-25K14 ZDRHD6DB3-4X/200-25XK14 ZDRHD6DB2-4X/200-50YK14
ZDRHD6DB3-4X/200-25YK14 ZDRHD6DB3-4X/200-50K14 ZDRHD6DB3-4X/200-50XK14
ZDRHD6DB3-4X/200-100K14 ZDRHD6DB3-4X/200-100XK14 ZDRHD6DB3-4X/200-50YK14
ZDRHD6DB3-4X/200-100YK14 DRHD6DP1-4X/200-100YK14
力士乐减压阀的构造类型很多，以往常见的有薄膜式、内弹簧活塞式等。减压阀的基本作用原理是靠阀内流道对水流的局部阻力降低水压，水压降的范围由连接阀瓣的薄膜或活塞两侧的进出口水压差自动调节。
