4WEH6…型方向阀

WEH是带电液操作的方向滑阀。
用于控制液流的开启、停止和方向。
此类阀组成足以包括阀体、控制阀芯、一个或两个复位弹簧和主阀及一个或二个电磁阀“A”（5.1）和电磁阀“B”（5.2）的小地方。
4WH…型方向阀
WH型方向阀是液控操作的方向滑阀。
用于控制液流的开启、停止和方向。
此类阀组成主要包括阀体、控制阀芯、一个或两个复位弹簧和主阀，在弹簧对中或弹簧复位的情况下，一级控制连接板
WMM型手动换向阀
——用手柄操纵的直动式换向滑阀
——供选的带复位弹簧或定位器

——板式连接

WH25HK50B/O6B
WH25HZ50B/O6B
WH25HE50B/O6B
WH25HF50B/O6B
WH25HG50B/O6B
WH25HH50B/O6B
WH25HJ50B/O6B
WH25HL50B/O6B
WH25HM50B/O6B
WH25HP50B/O6B
WH25HQ50B/O6B
WH25HR50B/O6B
WH25HS50B/O6B
WH25HT50B/O6B
WH25HU50B/O6B
WH25HV50B/O6B
WH25HW50B/O6B
WH25C50B/O6B
WH25D50B/O6B
WH25K50B/O6B
WH25Z50B/O6B
WH25E50B/O6B
WH25F50B/O6B
WH25G50B/O6B
WH25H50B/O6B
WH25J50B/O6B
WH25L50B/O6B
WH25M50B/O6B北京华德Z2S16A3-60B方向阀***
WH25P50B/O6B
WH25Q50B/O6B
WH25R50B/O6B
WH25S50B/O6B
WH25T50B/O6B
WH25U50B/O6B
WH25V50B/O6B
WH25W50B/O6B
WH32HC50B/O6B
WH32HD50B/O6B
WH32HK50B/O6B
WH32HZ50B/O6B
WH32HE50B/O6B
WH32HF50B/O6B
WH32HG50B/O6B
WH32HH50B/O6B
WH32HJ50B/O6B
WH32HL50B/O6B
WH32HM50B/O6B
WH32HP50B/O6B
WH32HQ50B/O6B
WH32HR50B/O6B
WH32HS50B/O6B
WH32HT50B/O6B
WH32HU50B/O6B
WH32HV50B/O6B
WH32HW50B/O6B
WH32C50B/O6B
WH32D50B/O6B
WH32K50B/O6B
WH32Z50B/O6B
WH32E50B/O6B
WH32F50B/O6B
WH32G50B/O6B
WH32H50B/O6B
WH32J50B/O6B
WH32L50B/O6B
WH32M50B/O6B
WH32P50B/O6B
WH32Q50B/O6B
WH32R50B/O6B
WH32S50B/O6B
WH32T50B/O6B
WH32U50B/O6B
WH32V50B/O6B
WH32W50B/O6B
HWH10HC20B/O6B
HWH10HD20B/O6B
HWH10HK20B/O6B
HWH10HZ20B/O6B
HWH10HE20B/O6B
HWH10HF20B/O6B
HWH10HG20B/O6B
HWH10HH20B/O6B
HWH10HJ20B/O6B
HWH10HL20B/O6B
HWH10HM20B/O6B
HWH10HP20B/O6B
HWH10HR20B/O6B
HWH10HS20B/O6B
HWH10HT20B/O6B
HWH10HU20B/O6B
HWH10HV20B/O6B
HWH10HW20B/O6B
HWH10C20B/O6B
HWH10D20B/O6B
HWH10K20B/O6B
HWH10Z20B/O6B
HWH10E20B/O6B
HWH10F20B/O6B
HWH10G20B/O6B
HWH10H20B/O6B
HWH10J20B/O6B
HWH10L20B/O6B
HWH10M20B/O6B
HWH10P20B/O6B
HWH10Q20B/O6B
HWH10R20B/O6B
HWH10S20B/O6B
HWH10T20B/O6B
HWH10U20B/O6B
HWH10V20B/O6B
HWH10W20B/O6B
HWH16HC50B/O6B
HWH16HD50B/O6B
HWH16HK50B/O6B
HWH16HZ50B/O6B
HWH16HE50B/O6B
HWH16HF50B/O6B
HWH16HG50B/O6B
HWH16HH50B/O6B
HWH16HJ50B/O6B
HWH16HL50B/O6B
HWH16HM50B/O6B
HWH16HP50B/O6B
HWH16HQ50B/O6B
HWH16HR50B/O6B
HWH16HS50B/O6B
HWH16HT50B/O6B
HWH16HU50B/O6B
HWH16HV50B/O6B
HWH16HW50B/O6B
HWH16C50B/O6B
HWH16D50B/O6B
HWH16K50B/O6B
HWH16Z50B/O6B
HWH16E50B/O6B
HWH16F50B/O6B
HWH16G50B/O6B
HWH16H50B/O6B
HWH16J50B/O6B
HWH16L50B/O6B
HWH16M50B/O6B
HWH16P50B/O6B
HWH16Q50B/O6B
HWH16R50B/O6B
HWH16S50B/O6B
HWH16T50B/O6B
HWH16U50B/O6B
HWH16V50B/O6B
HWH16W50B/O6B
HWH25HC50B/O6B
HWH25HD50B/O6B
HWH25HK50B/O6B
HWH25HZ50B/O6B
HWH25HE50B/O6B
HWH25HF50B/O6B
HWH25HG50B/O6B
HWH25HH50B/O6B
HWH25HJ50B/O6B
HWH25HL50B/O6B
HWH25HM50B/O6B
HWH25HP50B/O6B
HWH25HQ50B/O6B
HWH25HR50B/O6B
HWH25HS50B/O6B
HWH25HT50B/O6B
HWH25HU50B/O6B
HWH25HV50B/O6B
HWH25HW50B/O6B
HWH25C50B/O6B
HWH25D50B/O6B
HWH25K50B/O6B
HWH25Z50B/O6B
HWH25E50B/O6B
HWH25F50B/O6B
HWH25G50B/O6B
HWH25H50B/O6B
HWH25J50B/O6B
HWH25L50B/O6B
HWH25M50B/O6B
HWH25P50B/O6B
HWH25Q50B/O6B
HWH25R50B/O6B
HWH25S50B/O6B
HWH25T50B/O6B
HWH25U50B/O6B
HWH25V50B/O6B
HWH25W50B/O6B
HWH32HC50B/O6B
HWH32HD50B/O6B
HWH32HK50B/O6B
HWH32HZ50B/O6B
HWH32HE50B/O6B
HWH32HF50B/O6B
HWH32HG50B/O6B
HWH32HH50B/O6B
HWH32HJ50B/O6B
HWH32HL50B/O6B
HWH32HM50B/O6B
HWH32HP50B/O6B
HWH32HQ50B/O6B
HWH32HR50B/O6B
HWH32HS50B/O6B
HWH32HT50B/O6B
HWH32HU50B/O6B
HWH32HV50B/O6B
HWH32HW50B/O6B
HWH32C50B/O6B
HWH32D50B/O6B
HWH32K50B/O6B
HWH32Z50B/O6B
HWH32E50B/O6B
HWH32F50B/O6B
HWH32G50B/O6B
HWH32H50B/O6B
HWH32J50B/O6B
HWH32L50B/O6B
HWH32M50B/O6B
HWH32P50B/O6B
HWH32Q50B/O6B
HWH32R50B/O6B
HWH32S50B/O6B
HWH32T50B/O6B
HWH32U50B/O6B

WE10…31B/型电磁换向阀
——电磁铁操纵的换向滑阀
——湿式直流或交流电磁铁
——线圈可旋转901°
——可不放卸油液更换线圈
——集中或单个电器连接选择
——可选的手动操作
WEH…/WH…20B(50B)/…型电液换向阀（液控换向阀）
——电液换向阀/液动换向阀
——板式连接
——直流或交流湿式电磁铁任选
——带或不带故障检查按钮
——单独电器连接/集中电器连接
——弹簧对中或弹簧复位，或主控制滑阀的液压对中或液压复位到初始位置
——先导节流调节阀
——主控制阀芯的行程限位
——在主阀的P口上，有先导压力插装件
——当控制压力超过25MPa时减压阀降低先导压力
——插装节流孔降低对先导阀供油
WMD型旋钮换向阀
——用旋钮操纵的直动式换向滑阀
——板式连接
SV/SL…40B/系列液控单向阀
——液控单向阀
——连接尺寸按DIN24340
——底板安装或螺纹连接
——按需要有带卸油口和不带卸油口
——按需要有带先导阀和不带先导阀

——可选四种开启压力

HWH10Z20B/O6A
HWH10E20B/O6A
HWH10F20B/O6A
HWH10G20B/O6A
HWH10H20B/O6A
HWH10J20B/O6A
HWH10L20B/O6A
HWH10M20B/O6A
HWH10P20B/O6A
HWH10Q20B/O6A
HWH10R20B/O6A
HWH10S20B/O6A
HWH10T20B/O6A
HWH10U20B/O6A
HWH10V20B/O6A
HWH10W20B/O6A
HWH16HC50B/O6A
HWH16HD50B/O6A
HWH16HK50B/O6A
HWH16HZ50B/O6A
HWH16HE50B/O6A
HWH16HF50B/O6A
HWH16HG50B/O6A
HWH16HH50B/O6A
HWH16HJ50B/O6A
HWH16HL50B/O6A
HWH16HM50B/O6A
HWH16HP50B/O6A
HWH16HQ50B/O6A
HWH16HR50B/O6A
HWH16HS50B/O6A
HWH16HT50B/O6A
HWH16HU50B/O6A
HWH16HV50B/O6A
HWH16HW50B/O6A
HWH16C50B/O6A
HWH16D50B/O6A
HWH16K50B/O6A
HWH16Z50B/O6A
HWH16E50B/O6A
HWH16F50B/O6A
HWH16G50B/O6A
HWH16H50B/O6A
HWH16J50B/O6A
HWH16L50B/O6A
HWH16M50B/O6A
HWH16P50B/O6A
HWH16Q50B/O6A
HWH16R50B/O6A
HWH16S50B/O6A
HWH16T50B/O6A
HWH16U50B/O6A
HWH16V50B/O6A
HWH16W50B/O6A
HWH25HC50B/O6A
HWH25HD50B/O6A
HWH25HK50B/O6A
HWH25HZ50B/O6A
HWH25HE50B/O6A
HWH25HF50B/O6A
HWH25HG50B/O6A
HWH25HH50B/O6A
HWH25HJ50B/O6A
HWH25HL50B/O6A
HWH25HM50B/O6A
HWH25HP50B/O6A
HWH25HQ50B/O6A
HWH25HR50B/O6A
HWH25HS50B/O6A
HWH25HT50B/O6A
HWH25HU50B/O6A
HWH25HV50B/O6A
HWH25HW50B/O6A
HWH25C50B/O6A
HWH25D50B/O6A
HWH25K50B/O6A
HWH25Z50B/O6A
HWH25E50B/O6A
HWH25F50B/O6A
HWH25G50B/O6A
HWH25H50B/O6A
HWH25J50B/O6A
HWH25L50B/O6A
HWH25M50B/O6A
HWH25P50B/O6A
HWH25Q50B/O6A
HWH25R50B/O6A
HWH25S50B/O6A
HWH25T50B/O6A
HWH25U50B/O6A
HWH25V50B/O6A
HWH25W50B/O6A
HWH32HC50B/O6A
HWH32HD50B/O6A
HWH32HK50B/O6A
HWH32HZ50B/O6A
HWH32HE50B/O6A
HWH32HF50B/O6A
HWH32HG50B/O6A
HWH32HH50B/O6A
HWH32HJ50B/O6A
HWH32HL50B/O6A
HWH32HM50B/O6A
HWH32HP50B/O6A
HWH32HQ50B/O6A
HWH32HR50B/O6A
HWH32HS50B/O6A
HWH32HT50B/O6A
HWH32HU50B/O6A
HWH32HV50B/O6A
HWH32HW50B/O6A
HWH32C50B/O6A
HWH32D50B/O6A
HWH32K50B/O6A
HWH32Z50B/O6A
HWH32E50B/O6A
HWH32F50B/O6A
HWH32G50B/O6A
HWH32H50B/O6A
HWH32J50B/O6A
HWH32L50B/O6A
HWH32M50B/O6A
HWH32P50B/O6A
HWH32Q50B/O6A
HWH32R50B/O6A
HWH32S50B/O6A
HWH32T50B/O6A
HWH32U50B/O6A
HWH32V50B/O6A
HWH32W50B/O6A
HWEH10HC20B/O6BG24
HWEH10HD20B/O6BG24
HWEH10HK20B/O6BG24
HWEH10HZ20B/O6BG24
HWEH10HE20B/O6BG24
HWEH10HF20B/O6BG24
HWEH10HG20B/O6BG24
HWEH10HH20B/O6BG24
HWEH10HJ20B/O6BG24
HWEH10HL20B/O6BG24
HWEH10HM20B/O6BG24北京华德Z2S16A3-60B方向阀***
HWEH10HP20B/O6BG24
HWEH10HQ20B/O6BG24
HWEH10HR20B/O6BG24
HWEH10HT20B/O6BG24
HWEH10HU20B/O6BG24
HWEH10HV20B/O6BG24
HWEH10HW20B/O6BG24
HWEH10C20B/O6BG24
HWEH10D20B/O6BG24
HWEH10K20B/O6BG24
HWEH10Z20B/O6BG24
HWEH10E20B/O6BG24
HWEH10F20B/O6BG24
HWEH10G20B/O6BG24
HWEH10H20B/O6BG24
HWEH10J20B/O6BG24
HWEH10L20B/O6BG24
HWEH10M20B/O6BG24
HWEH10P20B/O6BG24
HWEH10Q20B/O6BG24
HWEH10R20B/O6BG24
HWEH10S20B/O6BG24
HWEH10T20B/O6BG24
HWEH10U20B/O6BG24
HWEH10V20B/O6BG24
HWEH10W20B/O6BG24
HWEH16HC50B/O6BG24
HWEH16HD50B/O6BG24
HWEH16HK50B/O6BG24
HWEH16HZ50B/O6BG24
HWEH16HE50B/O6BG24
HWEH16HF50B/O6BG24
HWEH16HG50B/O6BG24
HWEH16HH50B/O6BG24
HWEH16HJ50B/O6BG24
HWEH16HL50B/O6BG24
HWEH16HM50B/O6BG24
HWEH16HP50B/O6BG24
HWEH16HQ50B/O6BG24
HWEH16HR50B/O6BG24
HWEH16HS50B/O6BG24
HWEH16HT50B/O6BG24
HWEH16HU50B/O6BG24
HWEH16HV50B/O6BG24
HWEH16HW50B/O6BG24
HWEH16C50B/O6BG24
HWEH16D50B/O6BG24
HWEH16K50B/O6BG24
HWEH16Z50B/O6BG24
HWEH16E50B/O6BG24
HWEH16F50B/O6BG24
HWEH16G50B/O6BG24
HWEH16H50B/O6BG24
HWEH16J50B/O6BG24
HWEH16L50B/O6BG24
HWEH16M50B/O6BG24
HWEH16P50B/O6BG24
HWEH16Q50B/O6BG24
HWEH16R50B/O6BG24
HWEH16S50B/O6BG24
HWEH16T50B/O6BG24
HWEH16U50B/O6BG24
HWEH16V50B/O6BG24
HWEH16W50B/O6BG24
HWEH25HC50B/O6BG24
HWEH25HD50B/O6BG24
HWEH25HK50B/O6BG24
HWEH25HZ50B/O6BG24
HWEH25HE50B/O6BG24
HWEH25HF50B/O6BG24
HWEH25HG50B/O6BG24
HWEH25HH50B/O6BG24
HWEH25HJ50B/O6BG24
HWEH25HL50B/O6BG24
HWEH25HM50B/O6BG24
HWEH25HP50B/O6BG24
HWEH25HQ50B/O6BG24
HWEH25HR50B/O6BG24
HWEH25HS50B/O6BG24
HWEH25HT50B/O6BG24
HWEH25HU50B/O6BG24
HWEH25HV50B/O6BG24
HWEH25HW50B/O6BG24
HWEH25C50B/O6BG24
HWEH25D50B/O6BG24
HWEH25K50B/O6BG24
HWEH25Z50B/O6BG24
HWEH25E50B/O6BG24
HWEH25F50B/O6BG24
HWEH25G50B/O6BG24
HWEH25H50B/O6BG24
HWEH25J50B/O6BG24
HWEH25L50B/O6BG24
HWEH25M50B/O6BG24
HWEH25P50B/O6BG24
HWEH25Q50B/O6BG24
HWEH25R50B/O6BG24
HWEH25S50B/O6BG24
HWEH25T50B/O6BG24
HWEH25U50B/O6BG24
HWEH25V50B/O6BG24
HWEH25W50B/O6BG24
HWEH32HC50B/O6BG24
HWEH32HD50B/O6BG24
HWEH32HK50B/O6BG24

Z2S型叠加式液控单向阀
——用于垂直叠加安装
——按需要可以无泄漏封闭
一个或两个工作油口
S…P…1B型板式单向阀
——有一个方向无泄漏地封闭
——有五种开启压力
——板式连接
S型单向阀
——有一个方向无泄漏地封闭
——有五种开启压力
——管式连接直通单向阀
——板式连接
——插入式连接



4WH10G50B
4WH10H50B
4WH10J50B
4WH10L50B
4WH10M50B
4WH10P50B
4WH10Q50B
4WH10R50B
4WH10T50B
4WH10U50B
4WH1050B
4WH10W50B
3WH6A30B
3WH6C30B
3WH6D30B
3WH6B30B
3WH6Y30B
3WH6E30B
3WH6F30B
3WH6G30B
3WH6H30B
3WH6J30B
3WH6L30B
3WH6M30B
3WH6P30B
3WH6Q30B
3WH6R30B
3WH6T30B
3WH6U30B
3WH630B
3WH6W30B
4WH6A30B
4WH6C30B
4WH6D30B
4WH6B30B
4WH6Y30B
4WH6E30B
4WH6F30B
4WH6G30B
4WH6H30B
4WH6J30B
4WH6L30B
4WH6M30B
4WH6P30B
4WH6Q30B
4WH6R30B
4WH6T30B
4WH6U30B
4WH630B
4WH6W30B
3WH10A30B
3WH10C30B
3WH10D30B
3WH10B30B
3WH10Y30B
3WH10E30B
3WH10F30B
3WH10G30B
3WH10H30B
3WH10J30B
3WH10L30B
3WH10M30B
3WH10P30B
3WH10Q30B
3WH10R30B
3WH10T30B
3WH10U30B
3WH1030B
3WH10W30B
4WH10A30B
4WH10C30B
4WH10D30B
4WH10B30B
4WH10Y30B
4WH10E30B
4WH10F30B
4WH10G30B
4WH10H30B
4WH10J30B
4WH10L30B
4WH10M30B
4WH10P30B
4WH10Q30B
4WH10R30B
4WH10T30B
4WH10U30B
4WH1030B
4WH10W30B
HWEH10C20B/O6AG24
HWEH10D20B/O6AG24
HWEH10K20B/O6AG24
HWEH10Z20B/O6AG24
HWEH10E20B/O6AG24
HWEH10F20B/O6AG24
HWEH10G20B/O6AG24
HWEH10H20B/O6AG24
HWEH10J20B/O6AG24
HWEH10L20B/O6AG24
HWEH10M20B/O6AG24
HWEH10P20B/O6AG24
HWEH10Q20B/O6AG24
HWEH10R20B/O6AG24
HWEH10S20B/O6AG24
HWEH10T20B/O6AG24
HWEH10U20B/O6AG24
HWEH10V20B/O6AG24
HWEH10W20B/O6AG24
HWEH16C50B/O6AG24
HWEH16D50B/O6AG24
HWEH16K50B/O6AG24
HWEH16Z50B/O6AG24
HWEH16E50B/O6AG24
HWEH16F50B/O6AG24
HWEH16G50B/O6AG24
HWEH16H50B/O6AG24
HWEH16J50B/O6AG24
HWEH16L50B/O6AG24
HWEH16M50B/O6AG24
HWEH16P50B/O6AG24
HWEH16Q50B/O6AG24
HWEH16R50B/O6AG24
HWEH16S50B/O6AG24
HWEH16T50B/O6AG24
HWEH16U50B/O6AG24
HWEH16V50B/O6AG24
HWEH16W50B/O6AG24
HWEH25C50B/O6AG24
HWEH25D50B/O6AG24
HWEH25K50B/O6AG24
HWEH25Z50B/O6AG24
HWEH25E50B/O6AG24
HWEH25F50B/O6AG24
HWEH25G50B/O6AG24
HWEH25H50B/O6AG24
HWEH25J50B/O6AG24
HWEH25L50B/O6AG24
HWEH25M50B/O6AG24
HWEH25P50B/O6AG24
HWEH25Q50B/O6AG24
HWEH25R50B/O6AG24
HWEH25S50B/O6AG24
HWEH25T50B/O6AG24
HWEH25U50B/O6AG24
HWEH25V50B/O6AG24
HWEH25W50B/O6AG24
HWEH32C50B/O6AG24
HWEH32D50B/O6AG24
HWEH32K50B/O6AG24
HWEH32Z50B/O6AG24
HWEH32E50B/O6AG24
HWEH32F50B/O6AG24
HWEH32G50B/O6AG24
HWEH32H50B/O6AG24
HWEH32J50B/O6AG24
HWEH32M50B/O6AG24
HWEH32P50B/O6AG24
HWEH32Q50B/O6AG24
HWEH32R50B/O6AG24
HWEH32S50B/O6AG24
HWEH32T50B/O6AG24
HWEH32U50B/O6AG24
HWEH32V50B/O6AG24
HWEH32W50B/O6AG24
WEH10HC20B/O6AG24
WEH10HD20B/O6AG24
WEH10HK20B/O6AG24
WEH10HZ20B/O6AG24
WEH10HE20B/O6AG24
WEH10HF20B/O6AG24
WEH10HG20B/O6AG24
WEH10HH20B/O6AG24
WEH10HJ20B/O6AG24
WEH10HL20B/O6AG24
WEH10HM20B/O6AG24
WEH10HP20B/O6AG24
WEH10HQ20B/O6AG24
WEH10HR20B/O6AG24
WEH10HS20B/O6AG24
WEH10HT20B/O6AG24
WEH10HU20B/O6AG24
WEH10HV20B/O6AG24
WEH10HW20B/O6AG24
WEH10C20B/O6AG24
WEH10D20B/O6AG24
WEH10K20B/O6AG24
WEH10Z20B/O6AG24
WEH10E20B/O6AG24
WEH10F20B/O6AG24
WEH10G20B/O6AG24
WEH10H20B/O6AG24
WEH10J20B/O6AG24
WEH10L20B/O6AG24
WEH10M20B/O6AG24
WEH10P20B/O6AG24
WEH10Q20B/O6AG24
WEH10R20B/O6AG24
WEH10S20B/O6AG24
WEH10T20B/O6AG24
WEH10U20B/O6AG24
WEH10V20B/O6AG24
WEH10W20B/O6AG24
WEH16HC50B/O6AG24
WEH16HD50B/O6AG24
WEH16HK50B/O6AG24
WEH16HZ50B/O6AG24
WEH16HE50B/O6AG24
WEH16HF50B/O6AG24
WEH16HG50B/O6AG24
WEH16HH50B/O6AG24
WEH16HJ50B/O6AG24
WEH16HL50B/O6AG24
WEH16HM50B/O6AG24

DZ5DP型直动式顺序阀
——DZ5DP…10系列直动式顺序阀设定压力有2.5MPa、7.5MPa、15.0MPa、21.0MPa、31.5MPa五种，流量为15L/min，连接方式有底板连接和面板连接两种。
——DZ5DP…10系列直动式顺序阀具有体积小、重量轻、使用方便、的特点。
——本阀可以广泛地应用于起重机运输机械、建筑机械、工业车辆、机床、船舶、冶金等设备的液压系统中。
DZ6DP型直动式顺序阀
——DZ6DP…5X系列直动式顺序阀设定压力有2.5MPa、7.5MPa、15.0MPa、21.0MPa四种，流量为60L/min。
——DZ6DP…5X系列直动式顺序阀具有体积小、重量轻、使用方便、的特点。
——本阀可以广泛地应用于起重机运输机械、建筑机械、工业车辆、机床、船舶、冶金等设备的液压系统中。
DZ10DP型直动式顺序阀
——DZ6DP…4X系列直动式顺序阀（板式）设定压力有2.5MPa、7.5MPa、15.0MPa、21.0MPa四种，流量为80L/min，连接方式为底板连接。
——DZ6DP…4X系列直动式顺序阀具有体积小、重量轻、使用方便、的特点。
——本阀可以广泛地应用于起重机运输机械、建筑机械、工业车辆、机床、船舶、冶金等设备的液压系统中。