What Are the Characteristics of Triple Offset Butterfly Valves?

Triple offset butterfly valve is widely used in industrial pipelines such as metallurgy, electric power, petrochemical, water supply and drainage, and municipal construction, where the medium temperature is ≤425℃, for regulating flow and cutting off fluid. The materials of triple offset butterfly valve can be divided into cast iron, cast steel, and stainless steel. Here are some advantages of triple offset butterfly valve.

API specification of triple offset butterfly valve

Triple offset butterfly valve is designed and manufactured strictly according to the latest specification. Moreover, its basic design is not limited to just one specification. It can correspond to various specifications, ensuring its usefulness in all industrial fields.

Dual safety structure of triple offset butterfly valve

Triple offset butterfly valve is equipped with two independent thrust rings on the upper and lower sides of the disc to prevent disc deformation, stem displacement, and seal surface bite due to fluid pressure and temperature. To prevent sudden accidents caused by unknown reasons and stem breakage, there are independent stem flyout prevention devices inside and outside the bottom of the valve, which also ensures that the pressure level of triple offset butterfly valve can reach up to 2500 pounds.

Replaceable sealing seat of triple offset butterfly valve

The sealing seat of triple offset butterfly valve is unique. Not only can the valve body seat be replaced, but also the disc seal surface can be replaced. When the disc seal surface is damaged, it can be replaced without the need to transport the valve to the factory or disassemble the valve, which greatly reduces maintenance costs and saves repair time and effort.

Balanced fixed structure of triple offset butterfly valve

Based on the shape characteristics of the sealing surface of triple offset butterfly valve, the fixing method of the sealing seat adopts elliptical distribution fixing of bolts, which not only ensures precise positioning but also balances the force of each bolt, eliminating the looseness and leakage of the sealing surface caused by uneven stress distribution.

Dead zone-free design of triple offset butterfly valve

During the design process of triple offset butterfly valve, the application problems in the control field were specially considered. By fully utilizing the sealing principle of triple offset butterfly valve, the valve disc does not scrape the valve seat during opening and closing, and the stem torque is directly transmitted to the sealing surface through the disc. In other words, there is little friction between the disc and the valve seat, which eliminates the jumping phenomenon commonly seen when opening ordinary valves and various unstable factors that cause control failure in the low opening range of the valve, i.e., the dead zone. This means that triple offset butterfly valve can almost enter the adjustable area from 0 opening degree, and its normal control ratio is more than 2 times that of ordinary butterfly valves, with a control ratio of up to 100:1. This creates favorable conditions for triple offset butterfly valve to be used as a control valve, especially in large diameter applications. In addition, the cost of a globe valve is extremely high, and it cannot achieve zero leakage. In situations where emergency shutdown is required, a shutdown valve must be installed next to the globe valve. However, triple offset butterfly valve combines control and shutdown, resulting in significant economic benefits.

Construction of the valve body seat of triple offset butterfly valve

There are two installation structures for the valve seat of triple offset butterfly valve. Most of them are installed on the disc for convenience, but triple offset butterfly valve adopts the construction of installing the seat on the valve body. Its advantage is that compared with the disc seat, it greatly reduces the chance of the valve seat directly contacting the medium, thereby reducing the degree of erosion of the valve seat and prolonging its service life.

Thin-layer seat structure of triple offset butterfly valve

The valve seat of triple offset butterfly valve is composed of a stack of stainless steel thin sheets and graphite thin sheets, which can effectively prevent the influence of tiny solid particles in the medium and the seal surface bite caused by thermal expansion. Even if there is a small damage, it will not leak, which is unimaginable for other triple offset butterfly valves or double eccentric butterfly valves.