Fushiman Co.
Fushiman RVD19-2 type vacuum breaker
Manufacturer: Fushiman Co.,LTD.
Model: RVD19-2
| Model | Nominal diameter | Fluid | Maximum Operating Pressure | Maximum Operating Temperature | Body Material | Connection |
|---|---|---|---|---|---|---|
| RVD19-2 | 20-50 | water | 1.0 MPa | 90°C | CAC406 | Screw in |
This is a basic vacuum breaker with over 20 years of proven performance. It operates reliably with a simple structure.
If the piping or container becomes vacuumed and left as is, it may cause backflow or result in the container being crushed.
The RVD19-2 model quickly draws in air to break the vacuum when the piping or container is vacuumed.
Note: A check valve can be installed upstream of the RVD19-2 model to prevent backflow.
Features
Breaks vacuum quickly with a large suction volume.
Operates reliably with a very small pressure difference due to its diaphragm shape.
Maintains stable operation even under long-term pressure (up to 1 MPa) and temperature (up to 90°C).
All wetted parts are made of corrosion-resistant materials, so there is no concern about rust.
The valve body uses synthetic rubber, providing excellent sealing performance.
Specifications / Performance
| Fluid | Cold and hot water |
| Nominal diameter | 20・50 |
| Max operating pressure (MPa) | 1 |
| Max operating temperature (°C) | 90 |
| Min operating pressure (kPa) | −1.5 or lower |
| Valve body | Bronze |
| Diaphragm valve body | Synthetic rubber |
| Strainer | Stainless steel |
| Pipe connection | Threaded type JIS Rc |
| Application | Vacuum breaking for cold/hot water piping in refrigerators, hot water appliances, pools, bathrooms, dishwashers, medical equipment, etc. Also prevents negative pressure damage in air piping systems. |
Structure / Dimensions / Weight
| Nominal Diameter | 20 | 50 | |
| Dimensions | d | ¾ | 2 |
| H | 80 | 109 | |
| A | 108 | 140 | |
| Weight | 1.5 | 4 | |
Air Intake Volume
Usage Example
If a vacuum breaker is not installed in the diagram and, for some reason, valve A is closed, while a hose is submerged in a bucket at point B and water is drawn from a water fountain or another outlet at point C, the supply pipe may fall into negative pressure.
This can cause a reverse siphon effect, sucking water from the bucket into the drinking water system, leading to contamination.
However, if an RVD19-2 model is installed as shown in the diagram, when valve A is closed and negative pressure occurs near point B, the RVD19-2 quickly draws in air, preventing water from the bucket from being sucked into the system.
Precautions for Use
- Do not raise the downstream piping of the vacuum breaker.
- The vacuum breaker alone does not have a backflow prevention function. If used for backflow prevention, raise the pipe by at least 150 mm above the vacuum breaker as shown in the diagram, and install a check valve upstream of the vacuum breaker.
- Install it in a clean location and do not insulate the air intake opening.
- To prevent unexpected water leakage from the air intake, install it in a safe and drainable location.
Note:
If the water supply tank, etc., is filled above the inlet level, or if there is a risk of the water surface being higher than the tank, install a check valve and vacuum breaker to prevent backflow.
Also, install RVD19-2 where there is a risk of siphoning due to a sudden pressure drop.
