Industry: Oil & Gas
Application: Boiler Feedwater System
Location: Middle East Refinery Expansion Project
Boiler feedwater and steam systems in refineries operate under high pressure and temperature conditions, where any malfunction can lead to severe consequences such as equipment damage, operational downtime, or even catastrophic failure. Among the critical challenges in these systems is reverse flow during pump shutdown, which can cause water hammer, pump damage, and system inefficiency.
This case study explores how Non-Slam Axial Flow Check Valves provided an efficient, safe, and long-term solution to reverse flow issues in a Middle East refinery expansion project, replacing conventional swing check valves and preventing costly water hammer incidents.
The Challenge: Reverse Flow & Water Hammer in Boiler Feedwater Lines
During routine operations, the refinery experienced reverse flow during pump trip and shutdown in the boiler feedwater lines. This resulted in:
• Water hammer effects that damaged pipeline supports and fittings.
• High maintenance costs due to frequent failure of swing check valves.
• Risk of pump impeller damage, leading to costly repairs and downtime.
Problem Analysis:
• The existing swing check valves relied on gravity and reverse flow pressure to close, which delayed valve closure.
• This delay caused flow reversal and generated a shock wave (water hammer), creating significant mechanical stress.
The engineering team needed a reliable, maintenance-free check valve solution to eliminate reverse flow instantly, ensure silent operation, and withstand high-pressure steam and feedwater conditions.
Solution: Non-Slam Axial Flow Check Valves
The EPC contractor and refinery team decided to replace conventional swing check valves with Non-Slam Axial Flow Check Valves, specifically engineered for critical boiler feedwater applications.
Why Non-Slam Axial Flow Check Valves?
• Immediate Closure: Spring-assisted disc ensures fast and silent closure before reverse flow starts.
• Axial Flow Design: Maintains flow in a straight line, reducing pressure drop and turbulence.
• Water Hammer Prevention: Eliminates shock loads, protecting pumps and piping.
• Compact & Maintenance-Free: Designed for high-cycle, high-pressure environments without frequent servicing.
Valve Selection Parameters:
• Size: DN 100 to DN 300
• Pressure Class: ASME Class 600
• Material: ASTM A217 WC6 for high-temperature service
• End Connection: Butt Weld for high-pressure steam piping
Installation & Commissioning
The valves were installed on the main boiler feedwater pumps and steam condensate return lines. During commissioning, the team observed:
• Zero water hammer incidents during sudden pump trips.
• Silent operation, eliminating noise associated with conventional check valves.
• Improved reliability with no backflow detected.
The axial flow check valves performed flawlessly even during rapid start-stop cycles of feedwater pumps, ensuring system integrity and pump protection.
Results Achieved
• 100% elimination of water hammer in boiler feedwater lines.
• Extended pump life, reducing maintenance downtime and costs.
• Energy savings due to lower pressure drop compared to swing check valves.
• Improved safety and reliability of the entire steam and feedwater system.
Technical Performance Snapshot
| Parameter | Before (Swing Check Valve) | After (Non-Slam Axial Flow Check Valve) |
|---|---|---|
| Reverse Flow Incidents | Frequent | Eliminated |
| Water Hammer Effect | Severe | None |
| Pressure Drop | High | Low |
| Noise During Operation | High | Silent |
| Maintenance Frequency | High | Near Zero |
Non-Return Valve vs Non-Slam Axial Flow Check Valve
A common question arises: Are Non-Return Valves and Non-Slam Axial Flow Check Valves the same?
Answer: No, they are not the same, although both prevent reverse flow.
Non-Return Valve (NRV):
• A generic term for any valve that allows flow in one direction and prevents backflow.
• Includes various types like swing check valves, lift check valves, and ball check valves.
• Typically does not guarantee silent or instantaneous closure, leading to potential water hammer issues in critical systems.
Non-Slam Axial Flow Check Valve:
• A specialized type of NRV, designed with an axial disc and spring-assisted mechanism for fast, silent closure.
• Prevents water hammer by closing before reverse flow starts.
• Offers high reliability in high-pressure, high-temperature applications like boiler feedwater and steam systems.
Conclusion: All Non-Slam Axial Flow Check Valves are NRVs, but not all NRVs are non-slam axial flow types. For critical applications where water hammer elimination is essential, non-slam axial flow designs are the best choice.
Customer Feedback
“We were facing severe water hammer issues with our swing check valves in boiler feedwater lines. After replacing them with C-Way Engineering’s Non-Slam Axial Flow Check Valves, the problem disappeared completely. The valves are silent, reliable, and maintenance-free. This solution not only protected our pumps but also improved overall system efficiency. We highly recommend this technology for any high-pressure steam or feedwater system.”
— Project Engineer, Middle East Refinery Expansion
Why Industries and EPC Contractors Prefer Non-Slam Axial Flow Check Valves
EPC contractors often choose non-slam designs for critical pipeline applications because:
• They comply with API, ASME, and international standards.
• They provide long-term operational reliability, reducing warranty claims.
• They improve system safety, reducing the risk of catastrophic failures.
Key Standards & Compliance
• API 6D – Pipeline Valves
• ASME B16.34 – Valves Flanged, Threaded, and Welding End
• ISO 9001:2015 – Quality Management System
• CE Marking – European Compliance
The success of this project demonstrates the critical role of Non-Slam Axial Flow Check Valves in boiler feedwater and steam systems for refineries, power plants, and other high-pressure industries. By eliminating reverse flow and water hammer, these valves protect equipment, reduce maintenance costs, and enhance operational safety.
If you are an EPC contractor, project engineer, or plant maintenance manager dealing with similar challenges, upgrading to non-slam axial flow check valves is an investment in reliability and performance.
At C-Way Engineering Exports, we don’t just sell valves. We engineer solutions. With decades of experience in oil & gas, chemical, and EPC industries, we know what works in the field—not just on paper.
Our non-slam check valves are designed for the toughest environments, meeting global standards and ensuring your projects run safely, smoothly, and cost-effectively.
If you’re planning to upgrade your plant’s boiler feedwater system, don’t leave check valves as an afterthought. Talk to our engineering team today. We’ll provide the right valve, size it correctly, and keep your system safe from reverse flow nightmares.
Contact us now for technical assistance, sizing support, and competitive pricing.
