液压扳手由动力头、工作头、液压扳手专用泵以及高压油管，快速接头组成。通过高压油管，液压泵将动力传输到工作头，驱动工作头旋转螺母的拧紧或松开。

The hydraulic wrench consists of the power head, the working head, the special pump of the hydraulic wrench and the high pressure oil pipe, and the quick joint. Through the high-pressure oil pipe, the hydraulic pump transfers the power to the working head and drives the screw nut of the working head to tighten or loosens.

动力头油缸输出力，油缸活
Power head cylinder output force, cylinder life

塞杆与传动部分组成运动体，油缸中心到传动部件中心这个距离是液压扳手放大力臂。油缸出力乘以力臂，就是液压扳手理论输出扭矩，由于摩擦阻力存在，液压扳手实际输出扭矩要小于理论输出扭矩。
The piston rod and the drive part consist of a moving body. The distance between the center of the cylinder and the center of the drive part is the arm of the hydraulic wrench. The output of the cylinder is multiplied by the force arm, which is the theoretical output torque of the hydraulic wrench. Due to the existence of frictional resistance, the actual output torque of the hydraulic wrench is less than the theoretical output torque.

液压扳手分为两大类：中空液压扳手、方头液压扳手。方头液压扳手配合标准套筒使用，为通用型液压扳手适用范围广;中空液压扳手厚度较薄，特别适用于空间比较狭小的地方。适用于电力(核电、风电、水电、火电等)领域。
Hydraulic wrench is divided into two categories: square hollow hydraulic wrench, hydraulic wrench. The head of hydraulic wrench with standard sleeve used for a wide range of general-purpose hydraulic wrench; the thickness of the hollow hydraulic wrench is thin, especially suitable for relatively small space of the place. It is suitable for electric power (nuclear power, wind power, hydropower, thermal power and so on).

方头液压扳手特点：采用高科技航天材料及超高强度合金钢制造，一体成型机身，全面加强机身强度、韧性可360°×180°旋转的油管接头，无使用空间限制，自由操作;扳机式锁扣，轻松按动，可随心所欲地将360°微调式反作用力臂定于坚固的支点上;采用精密棘轮，精度高达±3%。中空液压扳手特点：方头采用超高强度轻金属，薄型设计，双作用，高速，大转角卡接式，互换插件，不需特殊工具，扭矩重复精度高达±3%，360°×180°的旋转软管接头，适合紧凑场合方便定位，扳手件强度设计充分，整体反作用力臂，较少的活动部件，耐用，可靠，可扩展的米制、英制六角插件和套筒，可实现一个动力头配备多个插件。

With hydraulic wrench features: the use of high-tech aerospace materials and ultra high strength alloy steel unibody, strengthen the body strength and toughness pipe joints 360 * 180 degrees rotation, without space restrictions, free operation; the trigger button, easily pressed, can arbitrarily be 360 degrees to fine tune reaction arm due to strong fulcrum; the precision ratchet, precision up to + 3%. Hollow hydraulic wrench features: square with ultra high strength lightweight metal, thin design, double acting, high speed, large angle clamping type, interchangeable plug-in, without special tools, torque repeat precision up to + 3%, rotary hose joint 360 * 180 DEG, suitable for compact occasions to facilitate positioning, wrench strength design fully overall, reaction arm, moving parts, less durable, reliable, scalable metric and inch six angle plug and socket, can realize a dynamic head equipped with multiple plug-ins.