1. Globe Valve VS Ball Valve
First of all, it’s important to distinguish between the Globe Valve and Ball Valve. The ball valve has a ball-shaped disc to close around the flow.
Though the globe valve also has a spherical body, the inner structure is totally different from the ball valve: the body is separated by internal baffles and there’s an opening inside that forms a seat onto which a movable plug can be screwed in to close the valve. Similar to the gate valve, the disc of the globe valve alos moves perpendicularly to the seat.
2. Basic Structure of Globe Valve
As it’s mentioned before, the globe valve usually has a spherical body that is separated into different partitions by baffles. On the opening of the partition, there’s the valve seat on which a movable plug can be moved up and down to regulate the fluid flow.
Due to the right angle contact between the disc and the seat, there’s a tighter seal between seat and disk, which assures less leakage from the globe valve than the gate valve.
3. Types of Globe Valve
According to the type of partitions in the valve body, there’re three types of globe valves.
The most common and simplest design is Z-Type: inside the valve body
There’s a Z-shaped partition that has an opening on which is the horizontal seat. This arrangement allows the stem and disk to travel perpendicular to the pipe axis resulting in very high pressure.
This design simplifies manufacturing, installation, and repair. This type of valve is used where pressure drop is not a concern and throttling is required.
In the case of Y Type globe valve, the partition inside the valve body is Y-shaped: the seat and stem are angled at approximately 45° to the pipe axis. Thus the disc may close the vale with high pressure.
This design can be used on occasions where pressure drop is concerned.
Not like the two types mentioned before, the Angle Type globe valve is less popular. It turns the flow direction by 90 degrees without using an elbow and one extra pipe weld. Disk open against the flow. This type of globe valve can be used in the fluctuating flow condition also, as they are capable of handling the slugging effect.
As professional valve manufacture, we produce a great variety of globe valves.
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