How do you identify a globe valve?
Gate valve operates in two direction and two-way flow. Gate valve runner in a horizontal line and the ordinary gate valve has a small flow resistance coefficient, that is about 0.08~0.12. Globe valves will only work in one direction and it has a larger amount of fluid trapping in the line due to the direction of flow.
What is API standard of globe valve?
As a valve design standard, API 623 affects all aspects of the globe valve. Since these valves are used primarily for throttling and regulating flows, the flow rate of various manufacturers should be close to API 623 globe valves.
What are the three types of globe valves commonly found?
There are three basic globe valve body designs: Tee, Angle, and Wye.
- Tee. This is the most common body type for a globe valve.
- Angle. The ends of this globe valve are at a 90° angle allowing fluid to flow in a single 90° turn.
- Wye. This type is an alternative for the high pressure drop commonly found in globe valves.
What type of globe valves are there?
There are three primary body designs for Globe valves, namely.. Tee Pattern or Z-body, Angle Pattern and Wye Pattern or Y-body body. Tee Pattern Globe valve design is the most common body type, with a Z-shaped diaphragm.
What is another name for a globe valve?
Globe valves are also known as throttle valves.
How do you size a globe valve?
When sizing a control valve, the rule of thumb is to size it so that it operates somewhere between 20-80% open at maximum required flow rate and whenever possible, not much less than 20% open at the minimum required flow rate.
What does API 600 mean?
API Standard 600, from the American Petroleum Institute, describes the criteria for valve design/construction and the material/trim designations for steel gate valves. The most recent version of this standard was published in January 2015, effective as of July 15, 2015.
What does API 598 mean?
API 598 covers the inspection, examination, and testing requirements for resilient-seated, nonmetallic-seated, and metal-to-metal-seated gate, glove, plug, ball, check, and butterfly valves.
What can go wrong with a globe valve?
Globe valve failures usually occur due to leakages in the disc, seat, stuffing box, sticking valve stems, and loose valve discs. Also, these failures can be caused by wrong valve size and material selection, poor maintenance of valve parts, or frequent use of the globe valves.
How do I calculate valve size?
The basic valve sizing equation Q = Cv√∆P can be used to calculate pressure drop, flow rate, or the flow coefficient. For solutions other than water, a correction for a difference in specific gravity of the solution is necessary. This revised formula would be: Q = Cv[√∆P/Sg] with Sg = specific gravity of the liquid.
How do I know what size valve I need?
What is the difference between API 600 and 602?
API 600 requires a heavier wall for a given pressure rating than does ASME B16. 34. API 602 also requires a heavier wall for 150#, 300# & 600# classes than does B16. 34.
What is the difference between API 6D and API 598?
API6D now references ISO 5208 leakage rates. The testing requirements differ slightly from API 598 (ISO 5208 is now mirrored to API598). The primary difference being 6D’s focus on valves with zero allowable leakage on closure (seating) tests which is achieved as most of the valves built to API 6D are resilient seated.
How do I stop my globe valve from leaking?
Globe Valve Repair /How to Re-Build a Globe Valve – YouTube
Can you flow backwards through a globe valve?
Also referred to as reverse flow or in globe valves, flow over the seat. Consider a drain plug in a bathtub. The flow direction is against the back or top of the plug (rather than the face) creating a tendency of the plug to close into the drain.
What is the formula of a valve?
How do I choose a valve?
The right valve choice means matching the valve’s size to expected flow through the system. Know the chemical compatibility requirements. The valve materials need to be compatible with the gases or liquids flowing through it. Plastic valves usually resist harsh or corrosive chemicals better than metal valves.
What does API 608 mean?
API 608 is a standard which exceeds the requirements set by ASME B16. 34, thereby offering a superior level of performance for the rigorous requirements of the petrochemical, power, oil and gas and water treatment markets.
What does API 602 mean?
API 602 is the 4″ & smaller forged steel gate valve purchase specification. Valve design and construction criteria are detailed, as well as materials and trim designations. Future versions of this document are expected to include requirements for bellows seal gate valves.
Can a globe valve be repaired?
—Repairing a globe valve involves reworking the disc and seat. —Due to pipe preparation, welding, heat treating and X-ray requirements, Butt Weld End valves require significantly longer changeout times. In the example above, the cost of repairing a Clampseal globe valve is just 10% of the cost of replacing it.
How do you maintain a globe valve?
Globe Valve Maintenance Training (do it yourself)-elearning – YouTube
Does it matter which way globe valve installed?
The globe valve must be installed in the proper relation to the media flow as indicated by the flow direction arrow marked on the valve body. This valve is considered uni-directional and must be installed with the pressure side or inlet under the seat.
How many turns does it take to open a globe valve?
Only a quarter-turn (90 degrees) is needed to open or close it—much faster than turning a handwheel multiple times. Quick closing can actually be a problem because of water hammer.
How do you fix a leaking globe valve?
How to Fix a Leaky Water Valve (Ball Valve) – YouTube
Do globe valves have a flow direction?
Globe valve have specific flow directions. Depending on the application, a globe valve will have fluid flow above or below the disc. Globe valves can be arranged so that the disk closes against or in the same direction of fluid flow.