Types and Functions of Water Tank Valves

Most buyers prioritize plate thickness, capacity and price when purchasing stainless steel water tanks, yet overlook the valve system, a core component determining system stability.

In practical engineering, malfunctions rarely stem from the tank itself but unreasonable accessory configuration:

• Frequent tank overflow leading to equipment room waterlogging

• Abnormal water supply triggering water cut-off

• Water backflow contaminating main pipelines

• Severe sediment accumulation hindering tank cleaning

• Structural damage caused by abnormal pressure

• Frequent later maintenance and rising operating costs

Though categorized as accessories, valves act as the control hub of the entire water storage system.

A well-developed stainless steel water tank system consists of the tank body and matched accessories as below:

• Liquid level control system

• Water inlet and outlet control system

• Sewage discharge structure

• Backflow prevention system

• Pressure protection system

• Inspection and maintenance system

• Channel steel base

Proper valve selection directly affects operational stability, water quality safety, maintenance costs and equipment service life.

Roles of Valves in Water Tank Systems

Valves do not merely switch water flow, but enable automatic and safe operation of water storage systems, undertaking four major core functions.

1. Water Level Control: Prevent Water Shortage and Overflow

Automatic water replenishment when water level drops;

Automatic shutdown once the preset water level is reached.

Poor liquid level control may result in continuous inflow, water overflow waste and idle pump running.

Liquid level control guarantees stable water supply for commercial buildings, schools, factories and other high-consumption scenarios.

2. Safety Protection: Avoid System Damage from Abnormal Pressure

Pressure fluctuations in closed and semi-closed water storage systems may cause pipeline impact, joint deformation, seal failure and irregular stress on tank bodies. Protective valves eliminate potential risks timely.

3. Sewage Discharge & Maintenance: Ensure Long-term Sanitary Operation

Long-term operation leads to sediment deposition, tiny metal particles, scale buildup and microbial breeding. Effective sewage discharge cuts down cleaning expenses.

4. Backflow Prevention: Safeguard Water Supply Quality

Pressure changes may push polluted water back into main pipelines. Backflow prevention check valves are widely equipped in large-scale projects.

Detailed Introduction to Main Valve Types and Functions

Float Valve – Core Component for Automatic Tank Operation

As the most commonly used accessory, float valves control water inlet opening and closing according to float position changes.

Working principle:

Water level decline → Valve opens → Automatic water replenishment → Reaching preset level → Valve closes → Water supply stops

Applicable scenarios

• Domestic stainless steel water tanks

• Fire water storage systems

• Water supply for commercial buildings

• Roof water storage tanks

Common Float Valve Categories

• Mechanical Float Valve

Low cost, easy installation and no power supply required, suitable for small and medium-sized tanks.

• Hydraulic Float Valve

Sensitive response and high control accuracy, ideal for large-capacity water tanks.

• Electric Liquid Level Valve

Capable of linkage control and high automation, applied in industrial facilities.

Common Malfunctions

1. Float failure

Causes: float aging, scale blockage, incorrect installation angle

1. Slow water replenishment

Causes: small valve caliber, insufficient water pressure

Selection Tips

Valve nominal diameter shall match pipeline flow demand.

Material recommendation: 304 stainless steel for regular environments; 316L stainless steel for highly corrosive environments.

Consult our sales team for cost-effective customized solutions.

Safety Valve – Guard Against Pressure-induced System Damage

Safety valves automatically release pressure once exceeding the preset threshold, widely used in closed water storage, pressurized water supply and hot water storage facilities.

Most stainless steel water tanks are storage containers instead of pressure vessels. Excessive pressure will trigger weld fatigue, joint leakage and tank deformation.

Key Performance Indicators

Opening pressure, sealing performance, flow capacity and reset precision

Installation Notes

Install on tank top or high positions; avoid additional stop valves that hinder pressure relief.

Drain Valve – Key to Efficient Cleaning and Water Quality Management

Absence of drain valves will sharply raise maintenance costs. Drain valves discharge bottom sediments, cleaning wastewater and residual maintenance liquid rapidly.

Common Drain Valve Types

• Manual Drain Valve

Simple structure, applicable to small and medium projects.

• Automatic Drain Valve

Timed drainage function, suitable for continuously operated industrial systems.

Necessity of Drainage Ports

Uncleaned water tends to turn turbid, breed bacteria and produce peculiar odor.

Inspect domestic water tanks every 6 to 12 months; formulate customized cleaning cycles for high-frequency usage systems.

Installation Suggestion

Arrange drain valves at the lowest position with reserved maintenance space.

Check Valve – Critical Part for Backflow Pollution Prevention

Check valves allow unidirectional water flow and block reverse backflow.

Typical Installation Positions

Main water inlet pipe, pump outlet, water replenishment system and rear end of pressurization equipment

Hazards without Check Valves

Water source contamination, pipeline impact, pump reverse rotation and abnormal water level

Common Check Valve Types

• Lift Check Valve: Vertical installation

• Swing Check Valve: Large flow conditions

• Silent Check Valve: Commercial buildings, reduces water hammer noise

Selection Criteria

Focus on opening pressure, sealing grade, installation direction and service cycle.

Valve Selection Principles to Frequent Replacements

Many operational faults arise from inferior accessories rather than defective tank bodies. Select valves based on the following aspects:

1. Caliber Matching

Choose larger caliber valves for high-capacity tanks to satisfy flow demand.

1. Material Selection

304 stainless steel for domestic water; 316L stainless steel for high-salinity environments; customized materials for special working conditions. Avoid mixed assembly of different metals.

1. Maintenance Convenience

Prioritize detachable structures to shorten downtime.

1. System Compatibility

Valves shall be compatible with pipe diameter, water pressure, interface standards and automatic control systems.

Daily Maintenance Advice for Fault Prevention

Establish annual inspection routine and check items below regularly:

Float flexibility, valve tightness, joint leakage, blockage, drainage efficiency and check valve performance.

Keep maintenance records to predict accessory service life.

Growing Importance of Professional Accessory Configuration

Buyers used to focus solely on tank prices, while currently paying more attention to long-term operational stability.

Reasonably configured valve systems bring multiple benefits:

• Improved water supply continuity

• Reduced overflow risks

• Extended tank service life

• Less frequent manual maintenance

• Enhanced water sanitation

• Lower long-term operating costs

Premium water tank solutions rely on integrated design of tank bodies, valves, installation and maintenance services. Bokang, a reliable domestic industrial water tank supplier, delivers comprehensive and trustworthy water storage system solutions.