Specification

TIANYU DN150 Cast Carbon Steel Gear-Operated Top Entry Ball Valve

I. Product Overview

TIANYU DN150 cast carbon steel gear-operated flanged trunnion type top entry ball valve is a heavy-duty flow control device engineered for medium to high-pressure industrial pipelines. As a top entry design, it features a trunnion-mounted ball, gear operation system, and flanged connections, primarily functioning to reliably shut off or regulate media such as oil, gas, steam, and industrial fluids. Constructed with cast carbon steel (WCB) for the body and high-grade stainless steel for critical components, it balances structural strength and operational precision. Suitable for pipelines requiring frequent maintenance or operating in harsh conditions, this valve integrates robust design with user-friendly features, making it a staple in petroleum, chemical, power, and natural gas sectors.

II. Key Attribute Parameters

Nominal Diameter: DN150 (6 inches), fitting medium to large industrial pipeline systems and meeting mainstream flow requirements.
Pressure Rating: Class 150, 300, 600 (1.6MPa, 2.5MPa, 4.0MPa), covering medium to high-pressure conditions, suitable for conventional industrial pipe networks to high-pressure process systems.
Body Material: Cast carbon steel (ASTM A216 WCB) with tensile strength ≥485MPa and yield strength ≥250MPa, offering excellent high-temperature resistance to withstand long-term erosion by high-temperature media.
Trim Materials:
- Ball: 316 stainless steel (ASTM A182 F316) with precision-ground surface, roundness error ≤0.01mm, ensuring tight fit of sealing surfaces;
- Seat: Metal-seated (Stellite alloy surfacing) or soft-seated (PTFE), adapting to different media corrosiveness and temperature requirements;
- Stem: 17-4 PH stainless steel, heat-treated to 30-35 HRC hardness, resistant to wear and corrosion.
Operating Conditions:
- Medium Temperature: -29℃ to 425℃, compatible with low-temperature oils to high-temperature steam and other media;
- Leakage Class: ANSI/FCI 70-2 Class V (metal seat) or Class VI (soft seat), ensuring bubble-tight sealing performance;
- Gear Operation Torque: 800-1200 N·m, labor-saving design for manual operation of large-diameter valves, also compatible with electric or pneumatic actuators for automation.
Connections & Standards:
- Flange Type: RF (Raised Face) per ANSI B16.5, with bolt hole layout and size matching the diameter, ensuring seamless docking with pipeline systems;
- Design Standards: API 6D, ANSI B16.34;
- Testing Standards: API 598, covering shell hydrostatic test, sealing test, and operational performance verification;
- Certifications: ISO 9001, CE, complying with international industrial safety and quality regulations.

Product Overview

III. Structural Features

Top Entry Design: The valve body has a removable top cover connected to the body via bolts. Internal components (ball, seat, stem) can be accessed and removed from the top for inspection or replacement without disassembling the entire valve or disconnecting the pipeline, significantly reducing maintenance time—ideal for systems with limited installation space or buried pipelines.
Trunnion-Mounted Ball: The ball is fixed by upper and lower trunnions, preventing displacement caused by media pressure and reducing wear on sealing surfaces. Compared to floating ball structures, its load-bearing capacity is 40% higher, maintaining stable operation even under Class 600 high pressure, extending service life.
Gear Operation System: Equipped with a worm gearbox with an optimized transmission ratio of 1:30, reducing manual operation force by 60% for easy opening/closing of DN150 large-diameter valves. The gearbox housing is made of cast iron with IP65 protection, dustproof and waterproof, suitable for outdoor or humid environments.
Safety Enhancements:
- Anti-blowout Stem: The stem features an inverted seal structure at the bottom to prevent accidental blowout under high pressure, meeting API 600 safety standards;
- Anti-static Device: A stainless steel spring connects the ball and valve body to discharge static electricity (resistance ≤10⁶Ω), avoiding spark risks from static buildup;
- Fire-safe Construction: The seat uses graphite backup sealing to maintain basic sealing performance after fire, complying with API 607 fire safety requirements.

IV. Manufacturing Processes

Body Casting: WCB cast carbon steel valve bodies are produced using resin sand casting, followed by annealing (650-700℃ for 4 hours) to eliminate internal stress and reduce deformation risks. Castings have surface roughness ≤25μm, no internal shrinkage or cracks, and pass 100% penetrant testing (PT).
Precision Machining:
- Valve flow channels and flange faces are machined by 5-axis machining centers, with dimensional tolerance controlled within ±0.05mm. Flange sealing surfaces have flatness ≤0.05mm to ensure tight fit with pipeline flanges;
- Balls are processed by CNC grinders, with surface roughness Ra≤0.8μm and sealing surface angle error ≤0.05° for reliable sealing;
- Gearbox gears are manufactured using high-precision hobbing, with tooth surface hardness ≥55 HRC and meshing clearance ≤0.03mm for smooth transmission.
Assembly & Testing:
- Seats are pre-assembled with spring preload adjustment to automatically compensate for sealing gaps during temperature changes;
- Valves undergo API 598 testing: shell hydrostatic test (1.5×nominal pressure for 30 minutes with no leakage); seat test (1.1×nominal pressure with bubble leakage ≤1 per minute);
- Operation test: 100 opening/closing cycles via manual gear operation to verify smooth operation, no jamming, and accurate position indication.
Surface Treatment: Valve bodies are sandblasted (Sa 2.5) and coated with high-temperature anti-rust paint (dry film thickness ≥100μm), passing 1000-hour salt spray testing for outdoor or high-humidity environments.

Valve Details

V. Product Advantages

Easy Maintenance: The top entry design allows internal component inspection from above without removing the valve or interrupting the pipeline, reducing maintenance downtime by over 50%—ideal for continuous production industries.
High-Pressure Stability: The trunnion ball structure distributes media pressure to prevent seal failure from ball displacement, maintaining stable sealing under Class 600 (4.0MPa) pressure, with 30% longer service life than floating ball valves.
Labor-Saving Operation: The gearbox transmission system significantly reduces operation force, enabling easy manual operation of DN150 valves, lowering labor costs and operator fatigue.
Safety & Reliability: Integrated anti-blowout stem, anti-static, and fire-safe features minimize leakage and accident risks, meeting strict safety requirements of high-risk industries (e.g., petroleum, natural gas).
Wide Compatibility: Flange dimensions comply with ANSI B16.5 for direct connection to international pipeline systems; multiple seat material options adapt to media from industrial water to corrosive chemicals, enhancing versatility.

Application

VI. Application Fields

Petroleum & Petrochemical Industry: Suitable for crude oil pipelines and refinery process lines, reliably shutting off or regulating crude oil and heavy oil, with gear operation adapting to outdoor installations.
Chemical Processing: Used in reactor feed lines and solvent transfer systems, with metal-seated versions tolerating high-temperature reaction media and soft-seated options for low-corrosion conditions.
Power Generation: Applied in power plant steam pipelines and boiler feed systems, with WCB material resisting long-term erosion by high-temperature steam for stable flow control.
Natural Gas Transmission: Utilized in natural gas pipelines and city gate stations, with anti-static and fire-safe designs reducing explosion risks from leaks, ensuring safe gas delivery.
Municipal & Industrial Utilities: Ideal for high-pressure industrial water circulation systems and central heating mains, with top entry design facilitating maintenance of underground pipelines.