Genuine Merrill R-40 brass valve body. This valve body is for the Merrill R6000 Yard Hydrant. The valve body is the piece underground that connects the hydrant to the plumbing. In the side of the valve body there is a small drilled hole called the weep, or drain hole. This hole insures that any water still inside of the pipe is drained once the hydrant is shut off. The inner diameter of the end that connects to the plumbing is approximately 1 1/4 inches. The inner diameter that connects to the hydrant is roughly 1 1/4.