A water bibcock is a device used to control water flow in and out of a pipe. Different sizes are available, so it's important to know which size you need before purchasing one. In this blog post, we'll discuss the different sizes of water bibcocks and provide some tips on choosing the right size for your needs. There are only two sizes as usual;1/2"x3/4" and 3/4"X1". with 1/2" and 3/4"BSP and NPT for the normal for the threaded connection