Gravity valve

The utility model relates to a gravity valve, consisting of a shell, a coping, a floater and a spring, wherein the shell is composed of a needle metering jet, a housing body, and a lower head, the bottom of the shell is fixedly sealed by the lower head; the coping contains a baffle, a main part and an external connected nozzle; the floater is arranged on the upper midsection with a cone, which form a needle valve together with the needle metering jet in the upper midsection of shell, the floater is arranged on the bottom with a concave part, which is provided with a convex stick inside; a spring sleeve is arranged on the convex stick in the hollow part; the gravity valve contains a access that is provided with a pressure regulating valve and is connected with the inner part with the external connected nozzle in a different passageway with the needle metering jet, the pressure regulating valve is arranged on the shell and underneath the coping baffle. The utility model realizes a pressure regulating of the oil tank through adding a pressure regulating valve on the gravity valve, and enables the steam be discharged from the oil tank through the pressure regulating valve, thereby avoiding distortion of the oil tank caused by the inner over pressure of.