Valves are essential type of fitting to any system as they regulate control and regulate fluid flow
within that system. There are numerous different types of valves such as ball valves, globe
valves, gate valves, butterfly valves, and many more. However, most valves can be broken down
into the same list of general components. The typical components found in the valve include the
valve body, a plug, seats, a stem, and packing to seal the valve.
LABELED PICTURE OF VALVE COMPONENTS
As a valve is designed to regulate flow it is critical that the plug properly contacts the seat
surface to create a seal that is leak-proof. Seats are classified in two separate categories: hard
seats and soft seats. Hard seats, made of metal and integral to the valve body, are typically found
in globe and gate valves. Soft seats, made of plastics or elastomers, are typically found in ball
and butterfly valves.
As these are seats are made of a much softer material than the plug, the design life of the valve
seats must be taken into consideration due to seat wear.