# 大乾国际贸易（海口）有限责任公司 > DAQIAN Valves, operating as 大乾国际贸易（海口）有限责任公司, is a leading Chinese industrial valve manufacturer specializing in high-performance solutions for power generation, oil & gas, petrochemical, and other critical industries. The company offers an extensive portfolio covering gate, globe, check, ball, butterfly, safety, control, and specialty valves in materials ranging from carbon steel to exotic alloys (titanium, nickel, zirconium). With a strong focus on intelligent manufacturing and compliance with international standards like API, ASME, and GB, DAQIAN provides custom-engineered large-diameter (up to DN3200) and high-pressure (Class 2500) valves, along with electric/pneumatic actuators, serving global EPC contractors and industrial end-users. The website is primarily in English, targeting international buyers. The contact page is located at /news.html. Product detail pages are individual, but this llms.txt focuses on category-level pages due to volume. Project update articles provide concrete evidence of manufacturing scale and standards compliance. DAQIAN emphasizes its Chinese identity with the slogan 'DAQIAN Intelligent Manufacturing · QIAN's Grand Realm'. ## Valve Product Series - [Oilfield Valve Series](https://www.daqianvalves.com/site-page/Oilfield-Valve-Series.html): High-pressure gate, globe, and check valves for oil and gas upstream and midstream, often API 6A compliant, with materials for sour service. - [Needle instrument Valve Series](https://www.daqianvalves.com/site-page/7bdd6072087642dd.html): Precision needle valves, manifold valves, and instrument isolation valves for chemical injection and pressure measurement. - [Check Valve Series](https://www.daqianvalves.com/site-page/5bf82d723a8d443e.html): Swing, lift, axial flow, and wafer check valves in cast iron, steel, and stainless steel to prevent backflow. - [Safety Valve Series](https://www.daqianvalves.com/site-page/2056664711d0400f.html): Spring-loaded and pilot-operated safety relief valves for overpressure protection in steam, gas, and liquid systems. - [Electric Actuator Series](https://www.daqianvalves.com/site-page/79b5ea8c3a9f4009.html): Multi-turn and quarter-turn electric actuators for remote valve automation, available with various torque and control configurations. - [Gate Valve Series](https://www.daqianvalves.com/site-page/d44ea6222b564478.html): Comprehensive range of gate valves: flanged, butt-weld, rising/non-rising stem, electric, pneumatic, and knife gate, for water, oil, gas, and steam up to high pressures. - [Power Station Valve Series](https://www.daqianvalves.com/site-page/75d61528b6ce4b4e.html): High-temperature and high-pressure gate, globe, and check valves engineered for power plant main steam, reheat, and feedwater systems per ASME B16.34. - [Forged Steel Valve Series](https://www.daqianvalves.com/site-page/728ceab8079848f1.html): Small-bore forged steel gate, globe, and check valves with socket-weld or threaded ends for high-pressure services. - [Preservative Valve Series](https://www.daqianvalves.com/site-page/220b8d6532a84430.html): Fluoropolymer-lined (PTFE, PFA) valves for corrosive chemicals, including lined ball, butterfly, plug, and globe valves. - [Copper Valve Series](https://www.daqianvalves.com/site-page/b0cdffcc76f94ff8.html): Brass and bronze gate, globe, ball, and check valves for plumbing, HVAC, and general industrial applications. - [Regulating Valve Series](https://www.daqianvalves.com/site-page/048e7231c8404605.html): Pneumatic and electric control valves with positioners for precise flow, pressure, and temperature modulation in process industries. - [Butterfly Valve Series](https://www.daqianvalves.com/site-page/0f7b2652ccfe4528.html): Wafer, lug, and flanged butterfly valves with soft or metal seats, manual and actuated, for on-off and throttling service. - [Titanium nickel zirconium Valve Series](https://www.daqianvalves.com/site-page/597bf596f815442c.html): Valves made from titanium, nickel alloys, and zirconium for extreme corrosion resistance in chlor-alkali, seawater, and chemical processes. - [Slab Type Knife Gate Valve Series](https://www.daqianvalves.com/site-page/a98e2c2b5b834956.html): Full-bore slab gate valves and knife gate valves for slurry, pulp, and wastewater, offering bi-directional tight shutoff. - [Water Power Control Valve Series](https://www.daqianvalves.com/site-page/168738d8e3f54ab6.html): Hydraulic control valves for water distribution, including pressure reducing, pressure sustaining, and pump control valves. - [Globe Valve Series](https://www.daqianvalves.com/site-page/0dcee1f3a1df4a08.html): Globe valves for flow regulation and isolation, available in straight, angle, and Y-pattern, with a wide range of materials and pressure classes. - [Special Valve Series](https://www.daqianvalves.com/site-page/e27a0d94a37e4059.html): Custom-designed valves for unique applications such as sampling, discharge, and process-specific requirements. - [Bellows Valve Series](https://www.daqianvalves.com/site-page/6f6bfb0485d540ba.html): Bellows-sealed gate and globe valves for zero-emission stem sealing in hazardous, toxic, or high-purity media. - [Ball Valve Series](https://www.daqianvalves.com/site-page/a485f46a19ad4e43.html): Floating and trunnion ball valves in various materials and configurations, including full-bore, reduced-bore, and V-ball for control. ## Project Updates & Case Studies - [DN500 Bevel Gear-Operated Pressure Seal Butt-Weld Gate Valve](https://www.daqianvalves.com/dn500-pressure-seal-butt-weld-gate-valve-main-steam): Delivery of a large DN500 gate valve for main steam service, designed to ASME B16.34 and JB/T 3595, demonstrating high-temperature, high-pressure capability. - [DN400 Y-Pattern Pressure Seal Butt-Weld Globe Valve](https://www.daqianvalves.com/dn400-y-pattern-pressure-seal-butt-weld-globe-valve-main-steam): Custom DN400 globe valve for 1000 MW thermal power units, featuring bevel gear operation and heat-resistant alloy construction. - [Integral Forging DN200 High-Temperature High-Pressure Pressure Seal Butt Weld Gate Valve](https://www.daqianvalves.com/power-plant-valves-dn200-forged-steel-pressure-seal-butt-weld-gate-valve): Forged steel gate valve for power plant steam lines, manufactured with integral forging for enhanced reliability in high-pressure service. - [DN1800 Electric High-Pressure Butt-Weld Gate Valve for Power Plants](https://www.daqianvalves.com/power-plant-dn1800-electric-pressure-seal-gate-valve): Custom-engineered DN1800 electric gate valve for main steam and long-distance pipelines, showcasing large-diameter manufacturing capability. - [DN400, Class 2500 Stainless Steel High-Pressure Gate Valves](https://www.daqianvalves.com/project/dn400-class2500-stainless-steel-gate-valve-power-plant-petrochemical): Delivery of high-pressure stainless steel gate valves from Class 600 to 2500, serving critical power and petrochemical applications. - [DN600 High-Temperature High-Pressure Pressure Seal Check Valve](https://www.daqianvalves.com/dn600-high-temperature-pressure-seal-check-valve): DN600 check valve for power plant high-temperature steam, complying with ASME and API standards for reliable non-return service. - [DN350 Bellows Sealed Globe Valve for Petrochemical & Power Plants](https://www.daqianvalves.com/dn300-dn350-bellows-seal-globe-valve): Bellows-sealed globe valve in DN300-DN350 for zero-leakage stem sealing in petrochemical and power plant applications, per DIN and ASME standards. - [DN3200 Motorized Large-Diameter Flanged Butterfly Valve](https://www.daqianvalves.com/dn3200-motorized-flanged-butterfly-valve-gas-pipeline): Huge DN3200 butterfly valve for coal gas and natural gas transmission pipelines, highlighting extreme large-diameter production expertise. - [DN1000 Large-Diameter Check Valve](https://www.daqianvalves.com/dn1000-large-diameter-check-valve-water-system): DN1000 check valve for water systems, made of ductile iron, compliant with EN standards, demonstrating large-diameter waterworks capability. - [Power Plant Valves: Engineered Reliability Solutions](https://www.daqianvalves.com/power-plant-high-performance-valves-thermal-gas-fired): Overview of DAQIAN's high-performance valve solutions for thermal and gas-fired power plants, focusing on reliability and system-level engineering. ## Technical Resources & Guides - [Power Plant High Pressure Valve Procurement Guide](https://www.daqianvalves.com/epc-valve-procurement-guide): In-depth guide for EPC contractors on risk-driven valve procurement, covering AVL qualification, lifecycle reliability, and engineering considerations. - [How to Avoid Costly Procurement Mistakes in Power Plant Valves](https://www.daqianvalves.com/avoid-power-plant-valve-procurement-mistakes): Article explaining common procurement errors in power plant valve selection and how engineering-driven approaches can prevent failures. - [R&D on Dynamic Characteristics and Control of Electric Regulating Valves](https://www.daqianvalves.com/CHNLGVFshu-zhong-guo-da-qian-fa-men-%E2%80%99s%20product%20development%20and%20manufacturing%20based%20on%20research%20on%20dynamic%20characteristics%20and%20control%20of%20electric%20regulating%20valves.html): Technical paper on electric control valve dynamic characteristics and control, demonstrating DAQIAN's R&D depth in automation. - [Research on Gas-Solid Two-Phase Flow and Wear in Gate Valves](https://www.daqianvalves.com/CHNLGVFshu-zhong-guo-da-qian-fa-men-%20Research%20and%20Solution%20Strategies%20on%20Gas-Solid%20Two-Phase%20Flow%20and%20Wear%20in%20Gate%20Valves.html): Research addressing gate valve wear in gas-solid flow, with solutions for extended service life in challenging environments. ## Company Information - [Home](https://www.daqianvalves.com): Landing page introducing DAQIAN Valves, highlighting key product series and recent projects. - [About Us](https://www.daqianvalves.com/about-us.html): Corporate overview of DAQIAN Valves, its mission, manufacturing philosophy, and global market commitment. - [Valve Product Introduction](https://www.daqianvalves.com/site-page/cab3c9c0d1df4a56.html): Comprehensive overview of DAQIAN's valve product lines, manufacturing capabilities, and application areas. - [News & Articles](https://www.daqianvalves.com/site-page/f043e1dbd2274848.html): Listing of recent project updates, technical articles, and company news. - [Contact Us](https://www.daqianvalves.com/news.html): Contact form and email for sales and technical inquiries, with response within 24 hours as stated.