1、 Core function: Dual guarantee of precise truncation and traffic regulation
Cast steel globe valveThe core function of achieving medium cutoff or flow through the linear motion of the valve disc and seat is reflected in:
Mandatory sealing mechanism
When the valve is closed, the valve disc is tightly attached to the valve seat, achieving zero leakage sealing through mechanical pressure, especially suitable for high temperature, high pressure, and strongly corrosive media (such as acid gas pipelines in the petroleum and chemical industries).
Case: In a catalytic cracking unit of a certain refinery, the cast steel globe valve operates stably at a high temperature of 500 ℃, effectively blocking hydrogen sulfide leakage and avoiding safety accidents.
Flow regulation capability
By adjusting the opening height of the valve disc (usually 25% -30% of the nominal diameter), the flow rate of the medium can be precisely controlled. For example, in the boiler feedwater system of the power industry, cast steel globe valves ensure stable water coal ratio and improve combustion efficiency by fine-tuning their opening.
Unidirectional flow control
The medium can only flow in the direction indicated on the valve body to prevent equipment damage caused by backflow. In the metallurgical industry, the one-way characteristic of cast steel globe valves in blast furnace gas pipelines avoids the risk of explosion caused by gas reflux.
2、 Structural advantage: high reliability under compact design
The structural design of cast steel globe valve balances strength and usability:
Compact valve body
Made of cast steel materials (such as WCB, ZG1Cr18Ni9Ti), the valve body thickness is increased by 30% compared to ordinary valves, and can withstand a high pressure of 42MPa (equivalent to 420 kg force/cm2), suitable for extreme working conditions such as deep-sea oil and gas exploration.
Threaded connection valve stem
The valve stem and valve cover are connected by trapezoidal threads, reducing disassembly time to less than 10 minutes for quick maintenance. According to statistics from a certain chemical enterprise, the use of cast steel globe valves has reduced equipment downtime for maintenance by 40%.
Multi stage sealing system
The valve cover is equipped with PTFE braided packing and graphite gasket double sealing, with a leakage rate of less than 0.01mL/min, meeting the API 598 standard. In the cooling water system of nuclear power plants, this design effectively prevents the leakage of radioactive substances.
3、 Selection key: Five step matching of working condition requirements
Medium adaptability selection
Corrosive medium: Choose 316L stainless steel valve body and Hastelloy valve disc, such as concentrated sulfuric acid pipelines in the chemical industry.
High temperature medium: WCB carbon steel valve body+ceramic valve seat, capable of withstanding temperatures up to 650 ℃, suitable for blast furnace gas pipelines in the steel industry.
Containing granular media: equipped with hard alloy valve discs, the wear resistance is increased by 5 times, suitable for mining tailings conveying systems.
Pressure level matching
Select the nominal pressure (PN) level based on the system pressure:
PN16 (1.6MPa): Suitable for building water supply and drainage systems.
PN40 (4.0MPa): Used for urban heating pipelines.
PN100 (10.0MPa): meets the requirements of long-distance oil and gas pipelines.
Optimization of Connection Method
Flange connection: The standard flange size complies with GB/T 9113, increasing installation efficiency by 50% and suitable for large equipment interfaces.
Welding connection: Adopting a butt welding structure, the pressure resistance is increased by 2 times, suitable for high-pressure steam pipelines.
Threaded connection: suitable for small-diameter pipelines below DN50, such as laboratory gas supply systems.
Driver configuration
Manual operation: Cost reduced by 30%, suitable for frequent opening and closing scenarios (such as fire water systems).
Electric actuator: supports MODBUS protocol, realizes remote control of DCS system, and is widely used in chemical continuous production.
Pneumatic actuator: response time ≤ 0.5 seconds, meeting emergency shutdown requirements, such as LNG storage tank safety valves.
Customization for special working conditions
Low temperature condition: Add an electric heat tracing device to the valve body to prevent liquid nitrogen freezing at -196 ℃.
Explosion proof requirement: Equipped with explosion-proof electric actuators, certified by ATEX, suitable for wellhead control in oil and gas fields.
Quick opening and closing:Cast steel globe valveAdopting a spring reset structure, the opening time is shortened to 1 second, suitable for fire sprinkler systems.