The
DBB MONOFLANGE Needle Valve, short for Double Block and Bleed monoflange needle valve, plays a vital role in industrial pipeline systems, especially in scenarios that demand high - level safety and precise fluid control.
The DBB monoflange needle valve integrates two shut - off needle valves and one bleed needle valve into a compact monoflange body. This integrated design significantly reduces the space and connection components required for traditional multi - valve assemblies, thereby minimizing potential leakage risks. For example, in common petrochemical pipelines, compared with using multiple independent valves, the DBB monoflange needle valve, with its compact structure, achieves complex blocking and bleeding functions in a limited space and reduces leakage points by up to 50%.
The valve body is usually made of high - quality carbon steel, stainless steel, or alloy steel through precision casting or forging, ensuring it can withstand harsh conditions such as high temperatures, high pressures, and corrosive media. In high - temperature and high - pressure steam pipelines, a valve body made of high - temperature - resistant alloy steel can operate stably, withstanding temperatures of up to 425°C and pressures of 10MPa. The valve seat and core are made of special alloys or hard materials and are finely ground to achieve a high - precision sealing fit, ensuring that the fluid can be effectively blocked when the valve is closed. The sealing class can reach the ANSI/FCI 70 - 2 Class VI standard, that is, bubble - tight sealing, eliminating any leakage.
During normal operation, the two shut - off needle valves are open, and the medium can flow through the valve chamber from the inlet end and out from the outlet end, while the bleed needle valve remains closed. When maintenance, repair, or system debugging of downstream equipment is required, first close the shut - off needle valve near the upstream to block the fluid from the upstream; then close the downstream shut - off needle valve to further ensure complete isolation of the valve chamber from the downstream equipment. Subsequently, open the bleed needle valve to safely discharge the residual medium in the valve chamber to a designated location, reducing the pressure in the valve chamber to zero and creating a safe environment for subsequent maintenance work.
In the maintenance operation of a certain natural gas transmission pipeline, by using the DBB monoflange needle valve and operating the shut - off and bleed needle valves in sequence, the pipeline section to be maintained was successfully isolated from the main pipeline, and the residual gas was discharged, ensuring the safety of maintenance personnel. The entire operation process was efficient and reliable.
The dual shut - off valve design provides a double - layer safeguard. Even if one shut - off valve fails to seal, the other can still effectively prevent medium leakage, greatly enhancing system safety. When handling toxic, harmful, flammable, or explosive media (such as chlorine gas, natural gas), this redundant design can avoid serious safety accidents and environmental pollution caused by leakage.
The valve core of the needle valve has an elongated needle - like structure. By rotating the adjustment handle, the gap between the valve core and the valve seat can be precisely controlled, enabling fine adjustment of fluid flow. In the feed control of chemical reactors, the DBB monoflange needle valve can accurately regulate the feed flow according to reaction requirements, ensuring the stable progress of the reaction, with a flow regulation accuracy of up to ±1%.
High - quality materials and precise manufacturing processes endow the valve seat and core with excellent wear - resistance and corrosion - resistance. In pipelines with particulate media, valve cores and seats made of special alloys can effectively resist particulate erosion, extending the valve's service life. Compared with ordinary valves, the service life can be extended by 2 - 3 times.
It is used in
wellhead installations, gathering and transportation pipelines, refineries, and natural gas processing plants to control the flow of crude oil, natural gas, refined oil, and other media, ensuring the safety and stability of production, transportation, and storage processes. For example, on offshore oil drilling platforms, DBB monoflange needle valves are installed on the pipelines of Christmas trees to achieve reliable blocking and bleeding of high - pressure oil and gas.
It is suitable for the pipelines transporting various corrosive chemicals and pharmaceutical raw materials, meeting strict safety and flow control requirements. In the aseptic drug production workshops of pharmaceutical factories, DBB monoflange needle valves made of corrosion - resistant stainless steel ensure the safe and accurate transportation of media during the drug production process.
It is used in steam pipelines of thermal power plants, coolant pipelines of nuclear power plants, etc., to ensure the safe operation of the system and equipment maintenance. In nuclear power plants, DBB monoflange needle valves are used to isolate and discharge the residual medium in the coolant system, providing a safe condition for equipment maintenance.
In conclusion, with its unique structure, reliable performance, and wide applicability, the DBB monoflange needle valve has become a key component in industrial pipeline systems to ensure safety and achieve precise control, providing strong support for the stable production and development of various industries.
