Before the introduction of the slab gate valve, gas valves had previously used single wedge gate valves and oil-sealed plug valves, but these solutions did not provide satisfactory performance. As a result, a parallel double gate valve was designed and successfully implemented to address the shortcomings of earlier models.
Gas valves play a crucial role in the gas industry. The Ministry of Construction has placed significant emphasis on standardizing gas valve construction. Several industry standards have been established, including CJ3005-1992 "General Technical Requirements for Gray Cast Iron Valves for Town Gases," CJ3055-1995 "Test and Inspection of Valves for Gas Use," and CJ3056-1995 "General Technical Conditions for Valves Made of Ductile Iron and Cast Steel for Town Gas." In June 2002, the industry standard for "Manual Gas Valves for Household Use" was also approved. These standards have helped regulate the valve industry, promote the development of gas valves, and support the growth of the gas sector. They serve as valuable references for manufacturers, users, and developers, enhance understanding of the differences between gas valves and general-purpose valves, ensure a higher safety margin, and are widely appreciated by gas professionals.
In the 1980s, China's gas supply mainly came from artificial coal gas, which contained more impurities and "gas glue." Traditional single-gate wedge gate valves were no longer sufficient to handle these conditions. To address this, gas-sealed plug valves were developed, which effectively solved the issue of stem sticking and improved sealing performance.
As the gas industry expanded and gas plants were built, there was an increasing demand for large-diameter gas-specific valves. Parallel double gate valves were introduced to meet these needs, with some models reaching up to 1600mm in diameter. Key features include:
1. The parallel double gate valve can scrape off "gas glue" from the sealing surface during operation, preventing impurities from affecting the valve’s sealing performance;
2. It is equipped with a protective cover for the valve stem, protecting it from corrosion caused by "gas glue";
3. A drain hole side cover at the bottom allows for cleaning debris that accumulates inside the valve chamber;
4. The full-bore design ensures low flow resistance and allows for pipeline pigging;
5. The valve body features a specially designed "squirrel cage frame rib" structure, reducing weight while enhancing strength and rigidity;
6. Made from gray cast iron, the gas gate valve offers a cost-effective solution;
7. The slab gate valve includes a fully enclosed opening and closing indicator, providing clear visual feedback to operators about the valve’s status.
Aluminum single hung window is a relatively new type of window. Here is a detailed introduction about it:
Structure and opening method:
Structure: Aluminum single hung window is mainly composed of aluminum alloy frame and window sash. Its frame structure is strong and can withstand large weight and pressure to ensure the stability and safety of the window.
Opening method: The window sash is opened and closed by pulling in the vertical direction. This opening method is different from traditional sliding windows or casement windows. It does not occupy the horizontal space indoors or outdoors and is particularly suitable for installation in locations with limited space, such as kitchens, bathrooms, narrow corridors, etc.
Advantages:
Good ventilation:Aluminum single hung windows can be opened to a large extent, so that indoor and outdoor air can circulate fully, effectively improving the indoor ventilation effect. In addition, some aluminum single hung windows can also realize multi-sash linkage to further increase the ventilation area.
Wide field of vision: Due to the particularity of its opening method, aluminum single hung windows will not be blocked by window frames like casement windows when opened, which can provide a wider field of vision and make the indoor space more transparent and bright.
High safety: When the window sash is closed, it fits tightly with the window frame, and with high-quality sealing strips, it can effectively prevent rain, dust, wind and sand from entering the room. At the same time, some aluminum single hung windows are also equipped with safety locks and other devices to enhance the anti-theft performance of the windows.
Easy to clean: The window sash can be tilted inward or outward, which is convenient for users to clean the inside and outside of the window, solving the problem of difficult cleaning of high-rise windows.
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