1. The core role of the ball valve
Rapid emergency cut-off
Open and close in seconds (response time < 1 second) by rotating 90°, used for sudden leakage or overpressure emergency cut-off of high-risk media (such as natural gas, high-temperature oil and gas).
The full-bore design has almost no flow resistance, reducing energy loss.
Accurate flow regulation
V-type ball valve (cut ball core) can finely control the raw material addition ratio of the chemical reactor, with an error of ≤1%.
Automated interlocking (such as combined DCS system) to achieve unattended adjustment.
Corrosion-resistant medium control
Metal hard sealing structure (such as cladding carbide) tolerates highly corrosive fluids such as acidic crude oil and sulfur-containing wastewater.
2. The core role of the gate valve
Reliable isolation of solid-containing media
The vertical lifting structure of the valve plate is not easily blocked by solids such as catalyst particles and coke slag, and is suitable for long-term full-open/full-close isolation of residual oil and slurry pipelines.
The straight-through flow channel has very little resistance to high-viscosity media (such as asphalt). High temperature and high pressure cut-off
The wedge gate has a stronger sealing surface pressure under high pressure (Class 600 and above), and is used for static sealing of steam main pipelines and hydrogenation reactor inlets and outlets.
The temperature resistance can reach 425℃, which is better than ordinary soft-sealed ball valves (limited to 180℃).
Large diameter pipeline foundation cut-off
Simple structure and low maintenance cost, suitable for low-frequency operation and large-diameter (DN＞300mm) pipelines such as the inlet and outlet main pipes of the storage tank area.
3. Comparison of typical application scenarios
Ball valve application scenarios
Emergency cut-off of liquefied petroleum gas (LPG) loading arm;
Flow regulation of cracked gas in ethylene cracking unit;
Automatic control of acid wastewater pipeline (fluorine-lined material required).
Gate valve application scenarios
Long-term open pipeline at the outlet of crude oil storage tank (maintaining low flow resistance);
High temperature residual oil transportation pipeline of delayed coking unit (resistant to particle scouring);
Full open/close control of steam heating main pipeline (resistant to high temperature and high pressure).
4. Limitations and complementarity
Limitations of ball valves: media containing hard particles are prone to damage the sealing surface, requiring a pre-filter; the opening and closing torque increases dramatically when the diameter is too large (DN＞500mm).
Limitations of gate valves: unable to adjust the flow; frequent opening and closing can easily cause the gate to become stuck or the sealing surface to wear.
Cooperative application: gate valves are used in the main pipeline to ensure basic flow, and ball valves are used in the branch pipeline to achieve rapid control, forming system-level safety redundancy.
