When it comes to preventing backflow in pipelines, two terms often come up: reflux valve and check valve. Are they different devices—or just different names for the same thing? If you’ve ever found yourself wondering this while working on a water, sewage, or industrial fluid system, you’re not alone. Let’s clear up the confusion.
What is a Check Valve?
A check valve—also known as a non-return valve (NRV)—is a mechanical device that allows fluid (liquid or gas) to flow in only one direction. It automatically prevents reverse flow using internal mechanisms like:
- A swinging disc
- A spring-loaded piston
- Or a ball and seat design
Check valves are critical in protecting pumps, preventing contamination, and maintaining system pressure. You’ll find them everywhere: water networks, process industries, fire systems, and HVAC.
What is a Reflux Valve
A reflux valve is a type of check valve, typically referring to a swing check valve used in water, wastewater, and plumbing systems. The term is more commonly used in specific regions like:
- Australia and New Zealand
- India
- South Africa
In these regions, you’ll often see “reflux valve” in civil drawings, pump specs, and plumbing codes—especially in municipal and stormwater applications.
Regional Terminology Matters
| Term | Regions Commonly Used |
|---|---|
| Check valve | Global (U.S., EU, international industry) |
| Reflux valve | Australia, NZ, India, South Africa |
| Non-return valve (NRV) | U.K., India, South Africa |
While all three refer to devices that stop reverse flow, the terminology varies based on region, industry, and even supplier.
Functional Differences?
There’s no technical difference between a reflux valve and a check valve if both refer to the same mechanism (e.g., a swing-type check valve). However:
- “Check valve” is a broad category
- “Reflux valve” is usually used to describe a specific application of a swing check valve in water-related systems
Common Application
| Application | Valve Type Often Used |
|---|---|
| Sewer mains | Reflux valve (swing check) |
| Pump discharge lines | Check valve (swing or lift) |
| Irrigation systems | Check or reflux valves |
| Fire suppression | Silent or spring-loaded check valves |
Key Takeaway
A reflux valve is a type of check valve—specifically used and named that way in certain regions.
If you’re working globally, “check valve” is the more universal and widely accepted term.
Final Thoughts
If you’re sourcing valves, writing specifications, or reviewing engineering plans, it’s important to recognize both terms. While they might describe the same function, choosing the right terminology helps ensure clear communication—especially across borders.
Whether you call it a reflux valve, a check valve, or an NRV, the goal is the same: keep the flow going forward—and nowhere else.
