A pressure regulating valve, comprising: a valve body provided with an inlet, an outlet, and a valve cavity in communication with the inlet and the outlet; a balanced valve element, the balanced valve element comprising: a valve rod having a first end and a second end, the valve rod defining a longitudinal axis extending between the first end and the second end; a piston sleeve fixed on the valve rod; a fixing member arranged between the valve rod and the piston sleeve, the fixing member extending in a direction parallel to the longitudinal axis of the valve rod and a valve seat fixed to the second end of the valve rod, wherein the piston sleeve comprises a sleeve body, a bottom and a first gap arranged between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod, the bottom of the piston sleeve is fixed on the valve rod; and an actuator fixedly connected to the valve body, the actuator coupled to the valve rod to move the valve seat within the valve cavity to control fluid flow through the valve body, wherein the actuator comprises: a pressure regulating means (331, 332); a diaphragm cap assembly comprising a first diaphragm cap and a second diaphragm cap, the first diaphragm cap being connected to the pressure regulating means (331, 332), the second diaphragm cap being connected to the valve body, and the first diaphragm cap mating with the second diaphragm cap to form a hollow internal portion; a diaphragm assembly comprising a diaphragm, the diaphragm being located between the first diaphragm cap and the second diaphragm cap; and wherein the pressure regulating means comprises a spring, characterized in that the pressure regulating means further comprises a regulating rod, wherein the spring is located inside of the first diaphragm cap and the regulating rod is fixed to the first diaphragm cap, and wherein the regulating rod has a third end that penetrates through the first diaphragm cap and is in contact to the spring, and a fourth end that is suspended. a valve body provided with an inlet, an outlet, and a valve cavity in communication with the inlet and the outlet; a balanced valve element, the balanced valve element comprising: a valve rod having a first end and a second end, the valve rod defining a longitudinal axis extending between the first end and the second end; a piston sleeve fixed on the valve rod; a fixing member arranged between the valve rod and the piston sleeve, the fixing member extending in a direction parallel to the longitudinal axis of the valve rod and a valve seat fixed to the second end of the valve rod, wherein the piston sleeve comprises a sleeve body, a bottom and a first gap arranged between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod, the bottom of the piston sleeve is fixed on the valve rod; and a valve rod having a first end and a second end, the valve rod defining a longitudinal axis extending between the first end and the second end; a piston sleeve fixed on the valve rod; a fixing member arranged between the valve rod and the piston sleeve, the fixing member extending in a direction parallel to the longitudinal axis of the valve rod and a valve seat fixed to the second end of the valve rod, wherein the piston sleeve comprises a sleeve body, a bottom and a first gap arranged between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod, the bottom of the piston sleeve is fixed on the valve rod; and an actuator fixedly connected to the valve body, the actuator coupled to the valve rod to move the valve seat within the valve cavity to control fluid flow through the valve body, wherein the actuator comprises: a pressure regulating means (331, 332); a diaphragm cap assembly comprising a first diaphragm cap and a second diaphragm cap, the first diaphragm cap being connected to the pressure regulating means (331, 332), the second diaphragm cap being connected to the valve body, and the first diaphragm cap mating with the second diaphragm cap to form a hollow internal portion; a diaphragm assembly comprising a diaphragm, the diaphragm being located between the first diaphragm cap and the second diaphragm cap; and wherein the pressure regulating means comprises a spring, characterized in that the pressure regulating means further comprises a regulating rod, wherein the spring is located inside of the first diaphragm cap and the regulating rod is fixed to the first diaphragm cap, and wherein the regulating rod has a third end that penetrates through the first diaphragm cap and is in contact to the spring, and a fourth end that is suspended. a pressure regulating means (331, 332); a diaphragm cap assembly comprising a first diaphragm cap and a second diaphragm cap, the first diaphragm cap being connected to the pressure regulating means (331, 332), the second diaphragm cap being connected to the valve body, and the first diaphragm cap mating with the second diaphragm cap to form a hollow internal portion; a diaphragm assembly comprising a diaphragm, the diaphragm being located between the first diaphragm cap and the second diaphragm cap; and wherein the pressure regulating means comprises a spring, characterized in that the pressure regulating means further comprises a regulating rod, wherein the spring is located inside of the first diaphragm cap and the regulating rod is fixed to the first diaphragm cap, and wherein the regulating rod has a third end that penetrates through the first diaphragm cap and is in contact to the spring, and a fourth end that is suspended.