The Design Standard of Ball Valve Is ANSI/API 608 Vs GB/T 12238

Overview of ANSI/API 608

1.1 Scope and Application

• Scope: API 608 is an American standard that specifies the requirements for metal ball valves with flanged, threaded, and butt-welded end connections. It is widely used in the oil, gas, and petrochemical industries.

• Applications: Suitable for process services involving flammable or hazardous materials, where robust sealing capabilities and durability are crucial.

1.2 Key Features

• Pressure and Temperature Ratings: API 608 valves are available in various pressure classes (e.g., Class 150, 300, 600) and are designed to operate efficiently in temperatures ranging from -20°F to 250°F (-29°C to 121°C).

• Material Selection: Common materials include carbon steel, stainless steel, and alloy steel. These materials provide durability and resistance to corrosion and high temperatures.

• Design and Construction: API 608 valves often feature trunnion-mounted ball designs for stability and reduced operating torque. They also include fire-safe design features and blowout-proof stems to enhance safety.

• Testing: Valves must undergo rigorous hydrostatic and pneumatic tests at 1.5 times the maximum allowable working pressure (MAWP) to ensure reliability and safety.

Overview of GB/T 12238

2.1 Scope and Application

• Scope: GB/T 12238 is a Chinese national standard that specifies the requirements for flanged and wafer-type butterfly valves. It is widely used in domestic and international pipeline systems.

• Applications: Suitable for a wide range of industrial applications, including chemical processing, water treatment, and general industrial use.

2.2 Key Features

• Pressure and Temperature Ratings: GB/T 12238 valves are available in various pressure ratings (e.g., PN10, PN16, PN25, PN40) and are designed to operate efficiently in temperatures ranging from -20°C to 200°C.

• Material Selection: Common materials include carbon steel, stainless steel, and other alloys. The standard emphasizes cost-effectiveness and broad applicability.

• Design and Construction: GB/T 12238 valves often feature simpler designs, such as floating ball configurations, which provide good sealing performance under normal operating conditions.

• Testing: Valves must undergo comprehensive testing, including pressure and leakage tests, to ensure basic performance and safety requirements.