Specification

DN25~DN300 PN1.0~1.6 API 6D SS316/CF3M Flanged Plug Valve

I. Product Overview

TIANYU API 6D plug valve is a high-performance flow control solution engineered for medium to high-pressure industrial systems. Crafted with stainless steel (SS316, CF3M, CF8M) and cast steel (WCB), it features a quarter-turn plug design and flange connection to ensure tight shut-off and flow regulation of water, steam, oil, and gas. Operating at -30℃~350℃ and PN1.0~1.6MPa, it combines metal-to-metal hard sealing with API 6D compliance to balance durability and precision. Ideal for oil & gas, chemical processing, power generation, and water treatment, it addresses the need for reliable shut-off in systems where leakage risks or flow direction control are critical.

II. Key Attribute Parameters

Size Range: DN25~DN300 (1″~12″), covering small to large-diameter pipelines for diverse flow control needs.
Pressure Range: PN1.0~1.6MPa (10~16bar), suitable for medium-pressure systems such as natural gas lines and steam auxiliary pipelines.
Temperature Range: -30℃~350℃, with stainless steel (SS316/CF3M) retaining toughness in low temperatures and resisting oxidation at high temperatures.
Material Configuration:
- Body & Bonnet: SS316 (corrosion resistance), CF3M (low carbon stainless steel for welded systems), CF8M (general corrosive media), WCB (cast steel for non-corrosive applications).
- Plug: SS316/CF3M, precision-machined to match the valve body’s sealing surface for tight shut-off.
- Seal: Metal-to-metal hard sealing (surface hardness ≥HB250), ensuring leak-tightness under pressure and temperature fluctuations.
- Packing: Graphite + stainless steel, preventing stem leakage and withstanding high temperatures.
- Actuation: Manual (quarter-turn handwheel), enabling quick on-off operation (90° rotation).
Connection Type: Flange (per ASME, DIN, JIS standards), ensuring secure integration with pipeline flanges.
Design Standards: API 6D, ASME, ASTM, ensuring compliance with global industrial and safety specifications.

Product Overview

III. Features Description

Quarter-Turn Operation: The plug rotates 90° to open/close, reducing operating time by 50% compared to multi-turn valves. This is critical for emergency shut-off in natural gas or oil pipelines, where rapid response minimizes leakage risks.
Metal-to-Metal Hard Sealing: The plug and valve body sealing surfaces are precision-ground (Ra ≤0.8μm) and lapped together, forming a tight seal that withstands high pressure and media erosion. It achieves ANSI/FCI Class V leakage (≤0.001% of flow), suitable for toxic or flammable media.
Lubrication System: Optional lubricant injection ports allow grease to be added to the plug surface, reducing friction during rotation and enhancing sealing. This extends service life in dusty or high-viscosity media (e.g., heavy oil) applications.
2/3-Way Versatility: Available in 2-way (on-off) or 3-way (flow direction control) configurations. 3-way models enable media diversion or mixing, eliminating the need for multiple valves in chemical dosing or heating systems.
Corrosion Resistance: SS316 and CF3M materials resist pitting from chlorides (e.g., seawater in offshore platforms) and oxidation from high-temperature steam, avoiding rust-related jamming or leakage.

IV. Manufacturing Processes

Material Preparation: Stainless steel castings (SS316/CF3M) undergo ultrasonic testing to detect internal defects. Chemical analysis verifies alloy content (Cr16-18%, Ni10-14%, Mo2-3% for SS316) to ensure corrosion resistance.
Plug & Body Machining: CNC machining centers precision-machine the plug and valve body to achieve a conical fit (tolerance ±0.02mm), ensuring uniform contact across the sealing surface. The sealing face is ground to Ra ≤0.8μm for tight sealing.
Sealing Surface Treatment: Metal sealing surfaces are hardened via nitriding (surface hardness ≥50HRC) to resist wear from repeated plug rotation, maintaining sealing performance over 10,000+ cycles.
Assembly & Testing:
- Hydrostatic Test: Body tested at 1.5×rated pressure (2.4MPa for PN1.6) for 30 minutes; seat tested at 1.1×rated pressure (1.76MPa) with water to confirm no leakage.
- Operation Test: 100+ open/close cycles to verify smooth rotation and consistent sealing, with special focus on lubrication system functionality.
- Corrosion Test: SS316 components undergo 48-hour salt spray testing to validate resistance to rust and oxidation.

Valve Details

V. Product Advantages

Tight Shut-Off Performance: Metal-to-metal sealing and precision machining achieve near-zero leakage, reducing media loss by 90% compared to soft-sealed valves in high-temperature (350℃) applications like steam lines.
Long Service Life: Hardened sealing surfaces and corrosion-resistant materials extend service life to 15+ years in industrial environments, lowering replacement costs.
Quick Operation: Quarter-turn design enables one-person operation of large-diameter valves (DN300), saving time in emergency shut-off scenarios.
Versatile Flow Control: 2/3-way options eliminate the need for valve manifolds, reducing installation space and complexity in chemical mixing or heating systems.
Global Compatibility: API 6D and ASME compliance ensures integration into international projects, avoiding rework for standard mismatches.

Application

VI. Application Fields

Oil & Gas Industry: Used in natural gas transmission and oil gathering lines, with SS316/CF3M resisting moisture and hydrocarbon corrosion, and tight sealing preventing flammable media leakage.
Power Generation: Controls steam flow in auxiliary systems (e.g., boiler feedwater), with metal sealing and high-temperature resistance (350℃) maintaining performance under thermal cycling.
Chemical Processing: Regulates solvent and reagent flow, with CF3M material avoiding contamination in welded systems and 3-way models enabling precise media mixing.
Water Treatment: Manages water and wastewater flow, with SS316 resisting chlorine-induced corrosion in disinfection lines.
Heating Systems: Controls hot oil flow in industrial heating loops, leveraging lubrication system to handle high viscosity and prevent plug jamming.