RKS fluid was founded in 1997. We are a production workshop for both foundry and machining, research & development center, and quality inspection cent...
Series: Candle Filter Filter core length: 800~2500 Filter cylinder dimensions: 550~2200 Filter cake specification:15~60mm Filter core number: 7~205 Filter area: 0.9~144.8㎡ Application: Biopharmaceutical, Chemical Industry, Food and beverages, Metal processing
Butterfly valves have been around for a long time, and are used for a variety of applications. They made their first appearance during the 1930s, and have been utilized by several industries ever since. Often made out of cast iron, butterfly valve's name is based from the functionality of its disc.
The wafer butterfly valve is one of the most common types of valves in industrial pipelines. The structure of wafer butterfly valve itself is relatively small. It is only necessary to put the butterfly valve in the middle of the flange at both ends of the pipe, and use the stud bolt to pass through the pipe flange and the pair.
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The manual valve is a valve operated by the handle and the hand wheel, and is a commonly used valve on the equipment pipeline.
DIN standard now uses EN standard structure length
EN 558-1 PN flange connection valve construction length (instead of DIN 3202), EN 558-2 CLASS flange connection valve construction length (instead of BS2080), EN 12982 butt weld end valve construction length (instead of DIN 3202), DIN standard The length of the structure including the length of the API valve is basically the same as the length of the GB...
The butterfly valve disc is a key component of the butterfly valve, which acts on closing and opening and closing. Butterfly valve seat and butterfly ...
Resilient-seated gate valve with bolted cover connection; made of ductile iron materials and with epoxy coating, designed as both clockwise and anti-c...
What is Kieselguhr Filter? What's the working principle of Kieselguhr Filter? The kieselguhr filter (Candle filter / Cake Filter) which we for customized for fluorine chemical plant six more lithium fluoride phosphate phosphorus process have been installed and working for two years
MINOTAUR series replaceable seat high performance butterfly valve
Butterfly valves are widely used in water transmission, industrial process systems, power plants and oil & gas pipelines.
Among different designs, double eccentric (double offset) and triple offset butterfly valves are commonly specified for demanding applications.
Although they may appear similar externally, their sealing principles and application suitability differ significantly.
1. Structural Principle Difference
Double Eccentric Butterfly Valve
A double eccentric butterfly valve features two offsets:
This geometry reduces seat friction during opening and closing. The disc quickly disengages from the seat after a small rotation angle, reducing wear compared to concentric butterfly valves.
RKSfluid ATHENA series follows this structural principle, designed for reliable sealing performance in medium to large diameter pipeline systems.
Triple Offset Butterfly Valve
In addition to the two offsets above, triple offset butterfly valves introduce: A conical sealing surface geometry (angular offset)
This design enables:
Triple offset valves are typically used in higher temperature and higher pressure applications, especially in oil & gas and petrochemical systems.
2. Sealing Mechanism Comparison
Double Eccentric:
Triple Offset:
Engineering Note:
Seat material and system conditions (pressure, temperature, media) are more critical than offset number alone.
3. Pressure and Temperature Range
Double Eccentric Butterfly Valves:
Triple Offset Butterfly Valves:
4. Application Scenario Comparison
Double Eccentric Butterfly Valve is commonly selected for: Municipal water transmission, Seawater intake and desalination plants, Cooling water systems, Large-diameter industrial pipelines, Medium pressure applications requiring reliable shut-off
Triple Offset Butterfly Valve is commonly selected for: Oil & gas pipelines, Refinery and petrochemical plants, High temperature systems, Steam service, Fire-safe critical installations
There is no universal superiority; selection must be based on system requirements.
When choosing between double eccentric and triple offset butterfly valves, evaluate:
For large-diameter water and general industrial systems, a properly designed double eccentric butterfly valve such as the ATHENA series can provide reliable performance and long service life.
For high-temperature hydrocarbon service or strict metal-to-metal sealing requirements, triple offset valves may be necessary.
Double eccentric and triple offset butterfly valves serve different but overlapping roles in industrial pipeline systems, Understanding sealing principle, pressure class and service condition is essential for correct selection.
If you have any further questions, don't hesitate to contact us! RKSfluid valve team has over 25 years of experience and is happy to help!
+86 138 8989 6699 
