The three eccentricities of the Triple Eccentric Butterfly Valve are refer to:
The first eccentricity: the valve shaft is located behind the valve plate,allowing the sealing Ring to closely surround the entire seat in contact.
The second eccentricity: the spindle is laterally offset from the center line of the valve body, which prevents interference with the opening and closing of the valve.
Third eccentricity: the seat is offset from the centre line of the valve shaft, which eliminates friction between the disc and seat during closing and opening.
How Does A Triple Offset Butterfly Valve Work?
The sealing surface of the triple offset eccentric butterfly valve is the bevel con, the seat on the valve body and the sealing ring in the disc is surface contact, eliminating the friction between the valve seat and the sealing ring, its working principle is to rely on the operation of the transmission device to drive the movement of the valve plate, the valve plate in the process of movement, its seal ring and the valve seat to get full contact, through the extrusion deformation to achieve sealing.
Triple eccentric butterfly valve has a prominent feature is to change the sealing structure of the valve, no longer the traditional position seal, but the torque seal, that is, no longer rely on the resilient deformation of the soft seat to achieve sealing, but rely on the pressure of the contact surface between the sealing surface of the valve plate and the valve seat to achieve sealing effect, which is also a good solution to the problem of large leakage of the metal seat, and because the contact surface pressure is proportional to the pressure of the medium, so the three eccentric butterfly valve also has a strong high pressure and high temperature resistance performance.
Triple Offset Butterfly Valve Video
Video From L&T Valves
The Benefits Of Triple Offset Butterfly Valves
Triple Offset Butterfly Valve Advantage
1)Good sealing performance, improve the reliability of the system;
2) Low friction resistance, open and close adjustable, open and close labor-saving, flexible;
3) Long service life, can achieve repeated switching;
4) Strong pressure and high temperature resistance, corrosion resistance, high wear resistance, wide range of applications;
5) Can start from 0 degrees into the adjustable area until 90 degrees, its normal control ratio is more than 2 times than general butterfly valves;
6) Different sizes and materials are available to meet different working conditions.
Triple Offset Butterfly Valve Disadvantage
1) Due to the special process of triple eccentric butterfly valve, the valve plate will be thicker, if the triple offset butterfly valve is used in the small diameter pipeline, the resistance and flow resistance of the valve plate to the flowing medium in the pipeline is great in the open state, so generally, the triple eccentric butterfly valve is not suitable for the pipeline under DN200.
2)In the normally open pipeline, the sealing surface on the seat of the triple eccentric butterfly valve and the multi-level sealing ring on the butterfly plate will be positively scoured, which will affect the sealing performance of the valve after a long time.
3)The price of butterfly triple offset valve is much higher than double eccentric and centerline butterfly valve.
Difference Between Double Offset And Triple Offset Butterfly Valves
Structure difference between double eccentric and triple eccentric butterfly valve
1. The biggest difference is that the triple eccentric butterfly valve has one more eccentric.
2. The difference of sealing structure, double eccentric butterfly valve is soft seal butterfly valve, soft seal sealing performance is good, but not resistant to high temperature, the pressure is generally not higher than 25 kg. And triple eccentric butterfly valve is metal seated butterfly valve, can withstand high temperature and high pressure, but the sealing performance is lower than double eccentric butterfly valve.
How To Choose Triple Offset Butterfly Valve?
Because the material of the triple eccentric butterfly valve can be selected from a wide range, and can correspond to high temperature and various corrosive media such as acid and alkali, so it is widely used in metallurgy, electric power, petrochemical industry, oil and gas extraction, offshore platforms, petroleum refinement, inorganic chemical industry, energy generation, as well as water supply and drainage and municipal construction and other industrial pipelines for regulating the flow and cut off fluid use. In the large diameter, with its zero leakage advantages, as well as excellent shut-off and adjustment function, is constantly replacing of the gate valve, globe valve and ball valve used in major industrial fields in a variety of important pipelines. Materials are as follows: cast iron, cast steel, stainless steel, aluminum bronze, and duplex steel. That is to say, in a variety of harsh conditions on the control line, whether as a switching valve or control valve, as long as the right selection, can be confidently used triple offset butterfly valve, and it is low cost.
Triple Offset Butterfly Valve Dimension
Data Sheet Of Butterfly Valve Triple Offset
| TYPE: | Triple eccentric, Wafer, Lug, Double flange, Welded |
| SIZE & CONNECTIONS: | DN80 to D1200 |
| MEDIUM: | Air, Inert Gas, Oil, Seawater, Waste water, Water |
| MATERIALS: | Cast Iron / Ductile Iron/ Carbon Steel / Stainless Steel / Alum Bronze |
| PRESSURE RATING: | PN10/16/25/40/63, Class 150/300/600 |
| TEMPERATURE: | -196°C to 550°C |
Material Of Parts
| PART NAME | Material |
| BODY | Carbon steel, Stainless steel, Duplex steel, Alum-Bronze |
| DISC / PLATE | GRAPHITE /SS304 /SS316 /Monel /316+STL |
| SHAFT / STEM | SS431/SS420/SS410/SS304/SS316 /17-4PH /duplex steel |
| SEAT / LINING | GRAPHITE /SS304 /SS316 /Monel /SS+STL/SS+ graphite/metal to metal |
| BOLTS / NUTS | SS316 |
| BUSHING | 316L+RPTFE |
| GASKET | SS304+GRAPHITE /PTFE |
| BOTTOM COVER | STEEL /SS304+GRAPHITE |
We Tianjin Zhongfa Valve Co., Ltd founded in 2006. We are one of the triple offset butterfly valve manufacturers in Tianjin China. We keep in high efficiency and strictly management of quality control, provide timely and effective pre-sale, sale and after-sales service in order to achieve effectiveness and customer satisfaction. We have gotten the ISO9001, CE Certification.