Abstract: An anti-tampering device for protectively housing a valve stem operator, wherein the valve stem operator is connected to a pipe. The device includes a skirted keeper body having a main aperture and a pair of spaced hooked legs for hooked up engagement with the pipe on either side of the valve stem and in depending relation to the body. The skirted keeper body further includes an upstanding member having a first padlock aperture and means for connecting the legs to the body. The device includes a cap having a first padlock end with a second padlock aperture such that when the cap is in overlaying relation to the main aperture, the padlock apertures of the cap and body are in alignment.