Trunnion Ball Valve can be 2 pcs and 3 pcs structure with metal seat or PTFE seat in forging or casting body which used to shut off or connect medium of pipeline, such as water, steaming, petroleum products, nitric acid, acetic acid or urea etc. Trunnion ball vavle usually suitable for big size and high pressure system with advantages of anti-static device design, blow-out proof stem, stable double sealing performance, long service life etc. The valve size can be from 8" to 42" with matching valve pressure from class 150 to class 1500 which operated by worm gear, handwheel, pneumatic actuator or electric actuator. Flange connection with pipeline is common type for trunnion ball valve.
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Granite introduction
Granite is a durable and resilient rock that resists acid, alkali, and weathering, making it a popular choice in construction. The term "granite" comes from the Latin word *granum*, meaning grain, and was later adopted into Chinese through Japanese translation. In early Meiji-era geological texts, granite was often translated as "granite" or "floe," with "flower" describing its attractive patterns and "gang" or "post" emphasizing its hardness—essentially, a rock with a flower-like appearance that is exceptionally tough. This translation has been widely accepted by Chinese scholars.
Granite is an intrusive igneous rock formed when magma cools and solidifies deep beneath the Earth's surface. Some granites may form through metamorphism of other rocks, resulting in gneiss or mixed lithology. Its primary minerals include feldspar, quartz, and mica (both black and white), with quartz typically ranging from 10% to 50%. Feldspar makes up about two-thirds of the composition and can be divided into potassium feldspar and plagioclase (sodium-calcium). Additional minerals like pyroxene and amphibole may also be present, depending on the type.
Known for its hardness, compact texture, high strength, and resistance to weathering, corrosion, and wear, granite is ideal for construction. It has low water absorption and can retain its color for over 100 years. However, it is not heat-resistant. Granite is categorized based on factors such as color, pattern, gloss, and structure. In Taiwan, the Ministry of Economic Affairs classifies granite into six types: black, brown, green, gray, light red, and deep red.
Despite its usefulness, granite can release radon gas—a naturally occurring radioactive gas—especially in certain regions. Prolonged exposure to radon has been linked to lung cancer. In Hong Kong, it’s estimated that 13% of lung cancer deaths are associated with radon exposure.
Granite is a coarse- to medium-grained intrusive rock rich in feldspar and quartz. It is the most common type of plutonic rock in the Earth’s crust, formed from cooling magma deep underground. Historically, granite mining was a significant industry due to its use in paving and building materials. It can occur as veins or large rock masses, often irregular in shape.
The composition of granite varies, with feldspar being the dominant mineral. Plagioclase and alkaline feldspar are both present, and their relative abundance helps classify different types of granite. In many granites, the ratio of these feldspars is less than 1:2. This type is commonly found in regions such as the eastern, central, and southwestern United States, parts of England, the Baltic Shield, and France. In some areas of the western U.S., plagioclase dominates over alkaline feldspar.
In contrast, granites with a higher proportion of alkaline feldspar are found in places like New England, the UK, and Oslo, Norway. These are usually smaller rock bodies but widespread in northern Nigeria. If quartz content is below 20%, the rock is not classified as granite. Dark minerals, such as amphibole or pyroxene, generally make up no more than 20% of the rock by volume.
The main minerals in granite include muscovite, biotite, hornblende, and pyroxene. Biotite is commonly found in all types of granite, while sodium amphibole and pyroxene are characteristic of alkaline granites. If neither feldspar type dominates, hornblende and pyroxene are unlikely to be the main minerals. Instead, dark minerals tend to be biotite or muscovite, or both.