1. Differences in the definition of terms
Check valve (Check Valve)
General category: refers to all the valves through the automatic opening and closing to achieve one-way fluid control of the general term, including lift, rotary opening, butterfly and dozens of other structural types.
Core function: global prevention of reverse flow of media to protect pipeline equipment safety.
NRV
Specific models or scenarios: mostly manufacturer-defined product model identification or segmentation scenarios application name, for example:
Danfoss (Danfoss) refrigeration check valve model, dedicated to the control of refrigerant unidirectional flow;
Flutec brands abbreviate High Pressure Check Valve as NRV;
In some literature, NRV is also used as an abbreviation for 'Silent Check Valve'.
2. Performance and application differences
| Terms | NRV(Scenario-specific products) | General check valves |
|---|---|---|
| Applicable medium | Refrigerant (e.g. Freon, CO₂) or high-pressure hydraulic fluid | Water, steam, gas, oil and other conventional media |
| Structural design | Optimised with damped piston, spring-assisted or welded seals | Conventional lift/swing/butterfly structure |
| Pressure rating | High-pressure version up to 1000 bar, low-pressure version for refrigeration systems | Conventional pressure range (0.01~42MPa) |
| Installation Requirements | Matching refrigeration pipework welded or flared connections required | Standard flange/threaded/pair clamp mounting |
3. summarise the relationship
NRVs essentially belong to a subset of check valves, and their specificity is reflected in:
Scenario specificity: optimised for refrigeration or high pressure hydraulic systems, e.g. Danfoss NRVs have a built-in damping piston to reduce the effects of refrigerant pulsation;
Customised design: sealing materials, connection forms and other parameters are differentially configured according to the manufacturer's application requirements.
While the general check valve needs to be adapted to a wider range of industrial scenarios, the selection needs to be comprehensive flow, media characteristics and other parameters.
