commom water valves can be categorized into the following six types based on their functions. In this section, we will briefly explain the working principles, characteristics, and application scenarios of each type of conventional valve.
Gate Valve
Working Principle:
The valve opens and closes by raising or lowering the gate perpendicular to the pipeline axis. When the gate is fully lowered, it seals against the valve seat, cutting off the flow. When fully raised, fluid can flow freely.
Characteristics:
Low fluid resistance when fully open, as the gate completely clears the flow path. However, the sealing surfaces are prone to wear during operation, making it unsuitable for frequent switching.
Application Scenarios:
Used for full open/close control in water supply and drainage pipelines, steam pipelines, and industrial medium transmission pipelines.
Globe Valve
Working Principle:
The disc moves along the centerline of the valve seat, adjusting the gap between the disc and the seat to control flow. Fluid enters from below the disc and exits above. Higher operating torque is required to overcome medium pressure during opening and closing.
Characteristics:
Excellent sealing performance and precise flow control, but higher fluid resistance.
Application Scenarios:
Steam pipelines, compressed air systems, and water supply and drainage pipelines requiring flow regulation.
Ball Valve
Working Principle:
A ball with a through-hole inside the valve body rotates to open or close the valve. When the hole aligns with the pipeline axis, the valve is fully open; when rotated perpendicularly, it closes.
Characteristics:
Quick operation, excellent sealing performance, and suitability for media containing particles. However, thermal expansion of the ball under high temperatures may cause jamming.
Application Scenarios:
Natural gas pipelines, petroleum transportation, chemical medium pipelines, and applications requiring frequent switching.
Check Valve
Working Principle:
The valve opens automatically under the pressure of forward flow and closes under reverse flow due to medium pressure and gravity, preventing backflow.
Characteristics:
Automatically prevents reverse flow using fluid pressure difference. Simple structure, effective against backflow, water hammer, and equipment damage.
Application Scenarios:
Pump outlets (to prevent backflow and pump damage during shutdown), steam pipelines, and gas pipelines (to prevent flashback).
Safety Valve
Working Principle:
Spring-loaded design: Under normal pressure, the spring force keeps the disc pressed against the seat. When system pressure exceeds the set value, medium pressure overcomes the spring force, opening the disc to release pressure. It closes automatically once pressure normalizes.
Characteristics:
Protects equipment from overpressure damage. Requires manual reset after activation.
Application Scenarios:
Safeguarding equipment from overpressure damage; requires manual reset after operation.
Pressure Reducing Valve
Working Principle:
Reduces high-pressure inlet medium to a set outlet pressure through throttling by the disc and maintains stable outlet pressure.
Characteristics:
Automatically regulates high-pressure inlet medium to a set low pressure via throttling and pressure feedback mechanisms, ensuring stability and energy efficiency.
Application Scenarios:
Water supply systems in high-rise buildings, residential gas pipelines (reducing high-pressure gas to household levels), and compressed air systems.
