During an emergency every component in fire protection systems plays a very vital role in ensuring prompt and dependable response. Amongst all the critical components in fire protection systems, swing check valves are most essential to maintain system integrity and optimal performance. In this article we explore the functioning of swing check valves in fire sprinkler systems and their critical role in protecting property and human life during fires.

Comprehending Swing Check Valves

Swing check valves are simple yet intelligent mechanical devices that permit flow of water only in one direction, while preventing its backflow. In a fire sprinkler system when water flows in the desired direction, a hinged disc or flapper swings open, but when the flow stops or reverses the flapper automatically closes.

Principal Advantages of Fire Safety

Quick Response:

Every second matters when a fire sprinkler head is activated. Water can swiftly reach the triggered sprinklers because of the low resistance by the flow check valves. Their simpler design means there are fewer moving parts that can malfunction at critical times.

Preventing Backflow: 

One of the main functions of the flow check valve is preventing the reverse flow of water through the system. This is essential for:

  • Maintaining system pressure
  • Preventing contamination of water supply
  • Assure that multiple sprinkler zones operate as intended
  • Protect pumps and other components of the system 

System Stability:

Flow check valves aid in keeping the sprinkler system’s pressure steady by blocking backflow. This stability is necessary for the sprinklers to operate appropriately and provide consistent coverage during a fire.

Considerations for Installation and Maintenance

Appropriate Installation

For swing check valves to work precisely, installing then with the right orientation is a must. Major installation requisites include:

  • Valve must be installed horizontally with the hinge pin on top
  • Provide adequate support to avoid stress on the connected pipes
  • Maintaining sufficient space for disc movement
  • Adhering to manufacturers specifications for flow direction 

Regular Maintenance

Although swing check valves are very simple devices, they do require routine maintenance:

  • Annual inspection of internal parts
  • Testing of valve operation and sealing  
  • Identifying signs of corrosion or wear and tear
  • Checking appropriate disc movement and seating

Common Applications

In fire sprinkler systems, swing check valves are usually installed in multiple locations:

  • After fire pump discharge
  • On floor control assemblies in high-rise buildings
  • In feed mains that supply multiple sprinkler zones
  • At connection to municipal water supplies

Criteria for Selection

While choosing swing check valves for fire sprinkler systems consider the following:

  • System pressure requirements
  • Flow capacity needs
  • Compatibility of materials
  • Adherence to local codes
  • Access requirements for maintenance
  • Weight and size  limitations

FAQs

Q1. When installing swing check valves, how should they be oriented?
It is important to install check valves:

  • Horizontally with the hinge pin on the top
  • In the appropriate flow direction as indicated by an arrow on the valve body
  • With sufficient support to avoid pipe stress
  • With enough space for disc movement

 

Q2. What is the recommended frequency for inspection of swing check valves?

According to NFPA standards:

  • Internal inspection once a year
  • Visual external inspection every quarter
  • Instant inspection after any system activation
  • Testing as a compulsory aspect of the commissioning of the entire fire safety system 

Q3. Which are the common maintenance problems of swing check valves?

Typical problems include:

  • Corrosion of internal parts
  • Damaged or worn out seals
  • Proper disc seating hampered by debris collection
  • Damaged or loose hinge pins
  • Valve operation affected by improper alignment 

Q4. What sizes of flow check valves are typically available for fire sprinkler systems?

Standard sizes available range from:

  • 2 inches ( 50 mm) to 12 inches ( 300 mm) for majority of applications
  • Customized size available for specific requirements
  • Pipe diameter and system flow requirements are used to determine the size  

Q5. What are the common pressure ratings for swing check valves?

Common pressure ratings include:

  • 175 PSI (12 bars) for standard applications
  • 250 PSI (17 bars) for high-pressure systems
  • 300 PSI (20.7 bars) for special applications

The working pressure must be equal to or greater than the system requirements.

 

Q6. What materials are generally used to construct swing check valves?

Typical materials used to manufacture swing check valves include: 

  • Cast iron or ductile iron bodies
  • Stainless steel or bronze trims
  • Seals made of EPDM or rubber
  • Hinge pins made of stainless steel
  • Specific, special materials for corrosive environments 

Q7. How can one determine if a swing check valve is functioning properly?

Indicators of correct operation include:

  • No water hammer when the system is operating
  • No leakage at valve connections
  • Proper maintenance of system pressure
  • Clean, uncluttered flow during testing
  • No unusual noises during system operation 

Q8. What are the indicators that indicate that the swing check valve needs to be replaced?

Replacements need to be done when:

  • Visible corrosion compromises the valves integrity
  • Repeated seal failures occur
  • There is noticeable wear and tear of internal components
  • Evident damage to the valve body
  • Repair costs are almost near to the new valve cost

Conclusion

Swing check valves are essential components of contemporary fire sprinkler systems. Their dependable performance protects the integrity of both the sprinkler system and water supply. It also guarantees efficient system operation in emergencies. They are a very essential link in the framework of fire protection components that work together to save lives and safeguard property. Regular inspection and maintenance of swing check valves should always be top priority in any comprehensive fire safety program.

STEELSTRONG VALVES is proud to offer a large range of valves that satisfy the intricate needs of different industries. The products in the spectrum include Cryogenic Valves, Globe, Check, Ball, Gate, Swing Check Valves. They are meticulously manufactured in accordance with BS, API, and ASME-ANSI specifications. The valves come in a range of sizes, pressure ratings, and materials, including alloy steel, carbon steel, duplex steel, stainless steel, and monel. Due to its versatility, Steelstrong can meet the needs of a wide variety of industrial applications. Steelstrong is ideally positioned to shape the valve industry’s future and set new standards for excellence in the process.