Brass ball valves, like all ball valves, control fluid flow by rotating a bored spherical ball to block or open the fluid path. They are available in 2- 3- or 4-way designs and have a variety of end connections. The primary components of Brass Valve are copper and zinc. The ratio of these vary depending on the desired mechanical properties, and additional elements such as tin, iron and lead are sometimes added to further improve certain properties. Of these additional elements, lead is the most common additive as it improves machine-ability. Lead has a lower melting point than zinc, so it is the last element in the alloy to solidify. It therefore squeezes into casting pores where it acts as a sealing agent and aids in machining by acting as a microscopic chip breaker and tool lubricant.