ACTUATED GLOBE VALVES
Theoretically, the globe valve has the best possible isolating characteristics as it is the only valve type whereby the disc movement is parallel with the direction of the flow and the torque applied via the operating mechanism directly seals the mating faces together. Globe valve bodies are available in various body styles, straight, angled or oblique patterns.
Flow direction is an important factor for Globe valves, if the flow is under to over the disc, the pressure acts on the underside of the disc and the operating mechanism must provide sufficient thrust to overcome the pressure load whilst also providing the additional forces required to mate the sealing faces within the valve.
MANUAL GLOBE VALVES
manual Globe valves usually have rising stems, and the larger sizes are of the outside screw-and-yoke configuration which secures the gland packing. All components of the Globe valve are similar to those of the gate valve. This type of valve has seats in a plane parallel or inclined to the line of flow.
Maintenance of Globe valves is particularly easy, as the discs and seats are readily refurbished or replaced. This makes Globe valves particularly suitable for services which require frequent valve maintenance. Where valves are operated manually, the shorter disc travel offers advantages in saving operator time, especially if the valves are adjusted frequently to regulate or isolate flow.
THE ADVANTAGES
The Globe valve presents good shut off and throttling capabilities, as with Gate valve, the Globe valve has a much shorter stroke and relatively quick to close. Various body styles are available in the form of tee, wye and also angled patterns which are all designed to offer their own and unique capabilities. Additionally, the globe valve can easily be refurbished by machining or resurfacing the seats. In terms of Globe valve sizing, they are generally restricted to a size of DN 12″ with the largest size that can be manually operated is 6″.
