Industrial NRV (Non-Return Valves)
What are Industrial NRV (Non-Return Valves)?
Non-return valves (NRVs), also known as check valves, allow fluid to flow in one direction only and automatically prevent backflow. These valves are essential in protecting equipment from reverse flow damage and maintaining system pressure.
Asiad Steel Industries manufactures durable NRVs for critical applications where flow direction must be regulated reliably and safely.
Key Features
- Prevents backflow – Ensures unidirectional flow
- Pressure-activated – No external operation required
- Maintenance-friendly – Simple design for easy servicing
- Compact and robust – Fits tight spaces and operates under pressure
- Available in multiple designs – Swing, lift, wafer, and spring-loaded
Types of NRVs
- Swing Check Valve
- Lift Check Valve
- Wafer Check Valve
- Dual Plate Check Valve
- Spring-loaded NRV
Specifications
Mechanical Properties
Chemical Composition
Equivalent Grades
Weight Chart
Specifications
| Parameter | Details |
|---|---|
| Sizes | ½” to 24″ (DN15 – DN600) |
| Pressure Rating | PN10 to PN40, Class 150 to 600 |
| End Connections | Flanged, Socket Weld, Threaded, Wafer |
| Materials | SS 304 / 316, Cast Iron, Bronze |
| Standards | API 6D, BS 1868, EN 12334, ASME B16.34 |
| Property | Value |
|---|---|
| Tensile Strength | 450 – 700 MPa |
| Yield Strength | 250 – 450 MPa |
| Elongation | 20% – 30% |
| Hardness | 120 – 220 HB |
| Temp. Range | -10°C to +200°C |
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Manganese | 0.5 – 2.0 |
| Silicon | 0.15 – 0.80 |
| Chromium | 18.0 – 20.0 (for SS) |
| Nickel | 8.0 – 10.5 (for SS) |
| Molybdenum | 2.0 – 3.0 (for SS 316) |
| Iron | Balance |
| Standard | Equivalent Grade |
|---|---|
| ASTM | A351 CF8 / CF8M |
| DIN | 1.4301 / 1.4401 |
| EN | X5CrNi18-10 / X2CrNiMo17-12-2 |
| JIS | SUS 304 / SUS 316 |
| Valve Type | Size (inches) | Weight (kg) |
|---|---|---|
| Swing Check Valve | 2″ | 6.0 |
| Wafer NRV | 4″ | 11.5 |
| Dual Plate NRV | 6″ | 19.0 |
| Lift NRV | 8″ | 33.0 |
| Flanged NRV | 12″ | 68.0 |
Applications of Industrial NRVs
Construction &
Infrastructure
Automotive & Heavy
Equipment
Manufacturing &
Fabrication
Medical & Laboratory
Equipment
Electrical &
Electronics Assembly
Oil, Gas & Petrochemical
Installations
Do you have questions?
Can NRVs be installed vertically and horizontally?
Yes, depending on the valve type. Swing and wafer NRVs are versatile but confirm the flow direction before installation.
How do NRVs prevent water hammer?
Spring-loaded and wafer check valves are designed for quick closing, minimizing water hammer impact.
What’s the difference between a swing check and a lift check valve?
Swing checks use a disc that swings open with flow; lift check valves move a piston vertically with pressure.
Are NRVs suitable for slurry or viscous media?
Special NRVs with full-flow designs or soft seats are suitable for handling slurries or semi-solid fluids.
