Yoshitake GD-55R-80 is a home boiler regulator used for hot water heat exchangers in cold areas. It features back-flow prevention, negative pressure operation, pressure balancing, an automatic recovery drain tap, and a built-in strainer.
Features
- The valve is pressure balance structure.
- Pipes can be installed either horizontally or vertically.
- Drain tap can operate by pushing and automatically recover to initial position.
- GD-91R can be easily installed by a cap nut, since the outlet connection is parallel screw.
- Valve and diaphragm are made of chlorine resistance synthetic rubber.



Specifications
| Application | Cold and hot water |
|---|
| Inlet pressure | 100-750 kPa |
| Standard set pressure | 80±6 kPa |
| Body | Bronze |
| Diaphragm | Synthetic rubber |
| Valve / Check valve | Synthetic rubber |
| Strainer | Screen: Stainless steel Frame: Synthetic resin |
| Strainer mesh | 60 mesh |
| Maximum temperature | 60°C |
| Connection | GD-55R, 56R: JIS Rc 3/4 GD-91R: JIS G 3/4 |
| Install direction | Horizontal and vertical |
Notes
- Standard set pressure 65 kPa (JIS approved) is available for GD-55R-65 and GD-56R-65.
- Standard set pressure 30-200 kPa is available for GD-55R and GD-56R.
| Open flow rate | 30 L/min or more |
|---|
| Closing pressure of back-flow prevent function | 3 kPa or less |
| Operate pressure of negative pressure operating function | Open: -55 kPa or less Close: 50 kPa or more |
INFO
- Open flow rate indicates the outlet flow rate when the inlet pressure is maintained at 100kPa and the outlet side is open.
Dimensions (mm) and Weights (kg)



Characteristic Charts


Maximum Pressure Limits
| Water pressure reducing valve | Relief valve for hot water maker | Max. pressure of hot water heat exchanger |
|---|
| 80 | 95, 97 | 100 |
| 85 | 97 | 100 |
| 120 | 190 | 200 |
| 150 | 190 | 200 |
| 170 | 190 | 200 |
| (Unit: kPa) | | |
Attention
Using the bold font valves to simple boiler (100 kPa) is illegal.
Precautions for Installation and Operation
- Clean up inside the pipe and remove foreign substances before installing the home boiler regulator.
- Water may leak from the negative pressure operating mechanism at the first time of water supplying. Please connect vinyl tube and conduct to drain.
- In the case of horizontal piping follow to the label and install the product sideways, in order to reduce remain water when draining.
- Please be sure to remove foreign substances and scales from inside of the piping before connecting the product to the piping.
- Install pipe at the relief valve outlet side and conduct to drain ditch. Also install the relief valve so as to check the operation visually.
- Relief valve will be opened by lifting the lever horizontally. Please check the operation 1-2 times a month.
- Styrofoam package can be used as heat insulating material to prevent freezing.
Piping Example

Structural Drawings


