When you are not the plumbing or hardware type, you can stare at webpage and wall after webpage and wall of fixtures and stainless steel valves and not really know what you are looking at. It is a Herculean task to be charged with purchasing replacement valves for your entire factory and not even know what a ball valve or a y-valve is. If you feel like you are drowning in a sea of valves, here are some definitions of more commonly-used valves to help you swim to the surface.
Spring Check Valves
These valves have an inner spring, hence the "spring" part of the name. The "check" part comes from the fact that these valves are used to check pressure, such as that found in a tire or in a gas or water line. They also help keep the pressure in check, a useful sort of valve if you have anything your plant that is under constant pressure (or should be!).
These valves have flanges on both ends. The flanges connect to pipes that also have flanges, creating a very secure pipeline. Flanged valves are essential to moving chemicals, crude oil and oil products, and anything that could potentially harm employees and should not be touched. Some flanged valves also operate as check valves. Additionally, you can buy flanged valves with or without their open/close handles on the tops of the valves. The open/close handles allow you to shut off and open valves manually in the event that your automated systems fail.
Globe valves are so named for their fat, rounded midsections that resemble globes. Many globe valves are also flanged or operate as check valves when additional components are built into or on the globe midsections. They are best used for liquids and semi-solids that are under constant pressure to flow from one part of the plant to another.
Y-Spring or Just "Y" Valves
Y-valves of any kind are named for their diverging "y" end. A singular pipe connects to one end, while two pipes connect to the "y" head end. They help divert liquid flow in two directions, such as when you need to fill two holding tanks with water or a dissolving chemical. Y-spring valves are y-valves with the spring check feature for monitoring high pressure in the lines and keeping the pressure constant. You may need a few of these sometimes.