Sometimes, you just need to turn the water or steam off. Say, for a safety check or a shutdown. You don’t need precise control, you just basically need “on” or “off”. Elsewhere in your system, though, you might need a little more precision in your flow control. For instance, when you’re trying to optimize your system’s efficiency or performance or fine-tune it after a restart.
Gate and globe valves are two of the most useful and popular valves in any boiler system. One is perfect for isolation, the other allows precise modulation to get everything just right. While gate and globe valves may look similar on the outside, the insides make all the difference when you’re trying to decide if you want full blast, full stop, or somewhere in between.
GATE VALVES
Gate valves are used primarily for starting and stopping the flow of steam or water. While they can provide some modulation, it only takes a small turn of the handle to get a fairly decent flow. They are better suited for isolation -- or for applications that don’t require much precision in flow restriction.
A gate valve works much like its name suggests. As you turn the handle, a gate slides across the valve body, perpendicular to the flow of water or steam. When the gate slides all the way into position, it seats against the opposite wall of the valve body and completely blocks the flow.
GLOBE VALVES
Inside a globe valve, you won’t find a gate. Instead, you’ll find a metal plug called a “globe” that is raised and lowered as the handle is turned. When the handle is turned all the way, the globe fits firmly into a matching seat on the other side of the valve, forming a very tight seal. Globe valves are the least likely to leak of any valve design out there, but while they are ideal for isolation, they are also a great choice for situations that require precise throttling. Say, for instance, matching feed water flow to the evaporation rate. Since the seat can be raised or lowered in very small movements, it puts a lot of control in your hands.
If you need a new valve installed, an existing valve serviced, or anything else for your boiler system, WARE is here to help with decades of expertise and a real passion for customer service.