Specification

TIANYU API Carbon Steel Trunnion Ball Valve – High Pressure

I. Product Overview

TIANYU API standard carbon steel WCB three-piece trunnion ball valve is a precision control device designed for high-pressure industrial pipelines. Adopting a trunnion ball structure and three-piece split design, its core function is to achieve rapid shut-off and regulation of media such as water, steam, oil, and natural gas. The main body is made of high-quality carbon steel (WCB), with a 304 stainless steel ball. It fits 2in-24in pipelines, covers pressure classes from Class 150-2500LB (1.6-42MPa), and operates stably under high and low temperature conditions. Via flange (RF/RTJ) or butt-weld (BW) connections, it complies with API, ANSI, and other international standards, widely used in high-pressure pipeline systems of petroleum, chemical, power, and natural gas industries, serving as a reliable flow control solution for complex working conditions.

II. Key Attribute Parameters

Specifications and Sizes:
- Size range: 2in-24in (DN50-DN600), covering medium and large pipeline needs;
- Structural dimensions: For 6in Class 150, length 394mm, height 280mm (specific dimensions increase with size and pressure class, complying with ANSI B 16.34).
Pressure and Temperature:
- Pressure class: Class 150/300/400/600/800/900/1500/2500 (1.6-42MPa), suitable for low to ultra-high pressure systems;
- Test pressure: Shell hydrostatic test at 1.5×nominal pressure, seat test at 1.1×nominal pressure, no leakage under pressure;
- Medium temperature: -29℃~425℃ (depending on sealing material), withstanding low-temperature LNG to high-temperature steam.
Materials and Sealing:
- Body material: Carbon steel WCB (ASTM A216), tensile strength ≥485MPa, suitable for high-pressure conditions;
- Ball material: 304 stainless steel (CF8), precision-ground surface with roundness error ≤0.01mm;
- Sealing material: PTFE (normal temperature), VITON (high temperature), ensuring bubble-tight sealing (leakage rate ≤0.1×10⁻⁶ mL/s);
- Seat: Spring-loaded structure to compensate for sealing gaps caused by temperature and pressure changes.
Connections and Standards:
- Connection types: RF flange, RTJ flange, butt-weld (BW), adapting to different pipeline systems;
- Design standards: API 6D, ANSI B 16.34;
- Test standard: API 598;
- Certifications: CE, SGS, ISO 9001, meeting international industrial safety regulations.

Product Overview

III. Structural Features and Design Advantages

The three-piece trunnion ball structure provides multiple core advantages:

Trunnion Ball Stability: The ball is fixed by upper and lower shafts, avoiding ball displacement caused by medium pressure, reducing seal face wear. Its service life is over twice that of floating ball structures, especially suitable for high-pressure conditions (Class 600 and above).
Three-Piece Easy Maintenance: The valve body consists of left, middle, and right sections connected by bolts. During maintenance, there is no need to disassemble the entire pipeline—only the middle section needs to be split to replace seals or the ball, reducing maintenance time by 50%.
Safety Protection Design:
- Anti-static device: 316L stainless steel spring connects the ball and valve body to discharge static electricity (resistance ≤10⁶Ω), preventing sparks from causing hazards;
- Fire-safe structure: The seat uses graphite backup sealing, maintaining basic sealing after fire, complying with API 607 fire safety standards;
- Anti-blowout stem: The stem has an inverted seal structure at the bottom to prevent stem blowout under high pressure, enhancing system safety.
Wide Working Condition Adaptability: The spring-loaded seat automatically compensates for sealing gaps caused by temperature changes, maintaining stable sealing within -29℃~425℃; optional seal materials adapt to corrosive (VITON) or sanitary (PTFE) media.

IV. Manufacturing Processes and Quality Control

TIANYU relies on a precision manufacturing system to ensure reliable performance of each valve:

Material Selection and Forging:
ASTM A216 WCB carbon steel billets are selected, with chemical composition verified by spectral analysis (C≤0.30%, Mn≤1.00%) to ensure mechanical properties; the ball is forged from 304 stainless steel (forging ratio ≥3) to eliminate internal defects, with tensile strength ≥520MPa.
Precision Machining and Grinding:
- Valve body: Integrally machined by CNC lathe, with flow channel inner wall roughness Ra≤1.6μm to reduce medium turbulence;
- Ball: Machined by high-precision grinder, roundness ≤0.01mm, surface roughness Ra≤0.8μm to ensure seal face fit;
- Flange: RF/RTJ seal faces are precision-machined by vertical lathe, flatness error ≤0.05mm, complying with ANSI B 16.5.
Assembly and Testing:
- Seat pre-assembly: Spring-loaded seats are tested for tightness under 1.5×working pressure to ensure no leakage;
- Overall testing: Each valve passes API 598 tests: shell hydrostatic test for 30 minutes without leakage, gas tightness test (0.6MPa nitrogen) with no bubbles;
- Non-destructive testing: 100% penetrant testing (PT) for key welds, and radiographic testing (RT) for high-pressure models.
Surface Treatment:
Carbon steel valve bodies are sprayed with anti-rust paint (dry film thickness ≥80μm); stems undergo nitriding treatment (hardness ≥800HV), passing a 1000-hour salt spray test to adapt to harsh environments.

Valve Details

V. Core Product Advantages

High Pressure Resistance and Long Life: Trunnion ball structure + WCB carbon steel body enables long-term operation under Class 2500 (42MPa) pressure, reducing seal face wear by 30% with a service life of over 15 years.
Safety Compliance: Integrating anti-static, fire-safe, and anti-blowout designs, passing API 607 and CE certifications, meeting safety requirements of high-risk industries such as petroleum and natural gas.
High Maintenance Efficiency: The three-piece design reduces seal replacement time to 2 hours (traditional one-piece requires 8 hours), lowering downtime losses.
Full Working Condition Adaptability: -29℃~425℃ temperature range + multiple seal material options, directly applicable to LNG low-temperature pipelines, high-temperature steam systems, and weakly corrosive media scenarios.
International Standard Compatibility: Sizes and pressure classes fully comply with API 6D and ANSI standards, enabling direct replacement of imported brands without adjusting pipeline layouts, reducing project adaptation costs.

Application

VI. Application Fields and Scenarios

Petroleum and Natural Gas:
- Wellhead Christmas trees: Control high-pressure crude oil flow, with trunnion ball structure withstanding frequent opening/closing wear;
- Natural gas pipelines: RTJ flange connections ensure no leakage under high pressure, anti-static design avoids explosion risks.
Chemical and Petrochemical:
- Reactor feed pipelines: Class 600 pressure class adapts to high-pressure reaction media, PTFE seals prevent chemical corrosion;
- Hot oil transportation systems: VITON seals withstand 300℃ high temperatures, ensuring no thermal oil leakage.
Power and Energy:
- Power plant steam pipelines: Class 300 controls high-temperature steam (425℃), fire-safe structure enhances system safety;
- Nuclear power auxiliary systems: Stainless steel internal parts resist radiation, meeting harsh environment requirements.
Municipal and Industrial:
- High-pressure water supply pump stations: Large-size (24in) models control main water transmission pipelines, with rapid shut-off function for emergency conditions;
- LNG receiving terminals: Maintain sealing under low-temperature conditions (-162℃), ensuring safe LNG transportation.

TIANYU three-piece trunnion ball valve, 2-24in, Class 150-2500, WCB carbon steel + 304 ball, adapts to multiple media. Trunnion ball stable, three-piece easy to maintain, meets API standards. Ideal for petroleum, power high-pressure systems, safe and durable.