Basics of Industrial Globe Valves

Exploded view of globe valve
(courtesy of Conval)

Globe valves work differently when compared to gate valves, ball valves, butterfly valves and plug valves in process control applications. They are primarily used to control the flow inside pipes, and are popular in a wide variety of industries. Globe control valves are ideal in situations where precise control is required. They are used to regulate flow in pipelines with a high degree of accuracy by regulating a pressures drop created in the valve body that allows the fluid to pass through the passageway (port) in the valve body. The control valve stem provides linear motion to control flow, opening and closing the valve by changing the distance between valve disc and seat. The flow in the pipeline changes according to the position of the disc lifting from the seat. The movement is controlled through the use of manual operators, or through the use of electric or pneumatic actuators.

Applications of Globe Valves

Globe valves are used in many different industries, but particularly in the petrochemical and power generation industries on fuel oil pipes, chemical feed systems, steam pipes, as well as cooling water and feedwater systems.  Other industrial applications of globe valve include boiler, main steam vents, and turbine lube oil systems.

Pros

Globe valves have many advantages that make them preferable over other valve designs. Globe control valves have excellent shut-off and throttling capabilities. In addition, globe valves are easy to maintain and repair compared to other valves.

Cons

Internal view of globe valve
(Conval)

Globe valves have also certain shortcomings. For instance, globe valves have an S-shaped flow pattern (as opposed to a straight-through flow pattern) which creates a significant pressure drop making them unsuitable for applications constant pressure is required.  Another shortcoming of the globe valves is they generally require greater torque to open and close, requiring larger actuators to properly seat the valve.

For more information on industrial globe valves, or any type of industrial valve, contact Piping Specialties, Inc. by calling 800-223-1468 or by visiting https://psi-team.com.

Top 3 Reasons to Specify the Conval Clampseal Gate and Globe Valves

1. Superior Rugged Construction - Conval valves are designed and built for extreme longevity. Features such as electroless nickel plated finish, complete material traceability of all wetted parts and yoke, instantly establish the quality of the Clampseal® Valve. The Clampseal® also has a pressure actuated backseat which provides maximum valve integrity by ensuring a positive internal stop for the valve stem and disc assembly. The actuated backseat extends packing life by securely isolating the packing from the pressure when the valve is fully open. Valves built forty years ago are still in service today.
2. In-Line Renewability - When inspection or servicing is required, Conval's in-line renewable valves do not need to be cut out (as do most other welded-in valves). The result is the shortest downtime and lowest life-cycle costs in the industry. A complete service, including a reground seat, new packing or stem replacement can often be accomplished in less than thirty minutes.
3. Renewal vs. Replacement - Renewing Clampseal® valves cost as little as 10% of the cost of replacing it. Renewing the packing is less than 4% of the cost of materials to replace a globe valve. In addition to the savings listed above, there are intangible savings from shorter shutdown time, which is considerable given that the cost of plant shutdown often exceeds the cost of equipment.

For more information on Conval gate and globe valves, contact Piping Specialties, Inc. by calling 800-223-1468 or visit https://www.psi-team.com.