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Globe valve, straight and angle type. Globe valves are the primary choice for throttling or regulating flow.
Normally it used in lines under 6".
For 6" and larger the valve used mostly commonly is either the gate or a butterfly type.
For this valve to operate efficiently, the manufacture recommends that it be installed with the direction of flow being from steam to seat side.
This will prevent chattering when throttling and makes closing the valve easier.
If there is a chance of hazard caused by the disc detaching from the valve and causing thus causing the valve to close then the installation should be reserved.
This flow direction is also recommended if a composition disk is being used as this will give less wear.
The angle body style has it’s ends at a right angle.
This is used to make a change in direction of piping without needing a 90 degree elbow.
When using this type consideration must be given to the higher stress created over the straight style.
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Regular-disk globe valves are not efficient for close regulation of flow because the disc and seat have a narrow contact.
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Plug-type disc globe valves are used for regulating in services with gritty liquids such as boiler feed water and for blow off services.
This type is less subject to wear under close regulation then the regular-seated valve.
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WYE-body globe valves have it’s in-line ports and stem emerging at about a 45 degree angle, hence the "Y".
It is the preferred style for erosive fluids because it has a smooth flow pattern.
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Double-disc globe valves have two discs which press against separate seats spaced apart on a single shaft.
This keeps the operator from the stresses of the conveyed fluid pressing into the valve.
This style does not ensure a tight shutoff.
It is usually used as a control valve or in a pressure regulator for steam or other gas services.
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Composition-disc globe valves are a good choice for coarse regulation and tight shut-off applications.
It is similar to a faucet in construction and the disc is easily replace.
The soft disc will imbed grit from the service which prevents seat damage and ensures that a good closure is achieved.
This style is not a good choice for close regulation though because it will cause the seat to become damaged quickly.
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