Fushiman Co.
Fushiman DMD31 type differential pressure valve for gas

Manufacturer: Fushiman Co.,LTD.
Model: DMD31
Model | Nominal diameter | Primary pressure measurement | Differential pressure setting range | Maximum operating temperature | Body Material | Connection |
---|---|---|---|---|---|---|
DMD31 | 32〜100 | Max. 1.0 MPa | 0.035 to 0.7 MPa | 80℃ | FC | Flanges |
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The DMD31 differential pressure valve is used in gas combustion lines, etc.
The primary valve is the PMD31 pressure reducing valve. For detailed specifications of the primary valve, please refer to the PMD31 pressure reducing valve (page 20 and beyond).
Specifications and Performance
Nominal Diameter | 32 | 40 | 50 | 65 | 80 | 100 | ||
Main Valve Fluid | Non-corrosive gases, including air | |||||||
Detecting Fluid | Non-corrosive gases, including air | |||||||
Primary Side | Maximum Pressure P₁ | 1.0 MPa | ||||||
Maximum Temperature | 80°C | |||||||
Secondary Side Pressure P₂ | 0.035〜0.7MPa | |||||||
Detecting Pressure P₃ | 1.0 MPa or lower | |||||||
Differential Pressure Setting Range ΔP (P₂ – P₃) | Refer to the right table | |||||||
Main Valve Performance (1) | Cv Value (3) | 6.3 | 8.3 | 13 | 21 | 29 | 50 | |
Minimum Pressure Difference (P₁ – P₂) | 0.02MPa | |||||||
Offset (3) | 10% or less of the maximum set pressure | |||||||
Shut-off Pressure Rise (3) | 0.01〜0.02MPa | |||||||
Minimum Adjustable Flow Rate (3) | 5–10 m³/h (standard state) | |||||||
Valve Seat Leakage Rate | 0.01% or lower of rated flow | |||||||
Main Component Materials | Valve Body | Cast Iron | ||||||
Spring Guard | Cast Iron | |||||||
Valve Body | Stainless Steel (Contact Surface with Synthetic Rubber) | |||||||
Valve Seat | Bronze | |||||||
Diaphragm | Synthetic Rubber | |||||||
Main Valve & Pipe Connection | Flange Type, JIS 10K Full Face |
Notes:
- The main valve performance values are based on a detected pressure P₃ of 0 kPa (atmospheric pressure).
- The Cv value is the same as that of the PMD31 pressure reducing valve (see page 20 for reference).
- Offset, shut-off pressure rise, and minimum adjustable flow rate are reference values (target values).
Structure and Dimensions
Dimensions
Nominal Diameter (mm) | L (mm) | H₁ (mm) | H₂ (mm) | H₃ (mm) | E (mm) | Weight (kg) |
---|---|---|---|---|---|---|
32 | 175 | 80 | 347 | 136 | 155 | 14 |
40 | 190 | 80 | 347 | 136 | 155 | 16 |
50 | 195 | 80 | 347 | 136 | 155 | 17 |
65 | 230 | 104 | 443 | 163 | 210 | 34 |
80 | 250 | 104 | 443 | 163 | 210 | 35 |
100 | 290 | 127 | 481 | 185 | 250 | 58 |
Installation Example
The nominal diameter selection and piping examples for the DMD31 differential pressure valve are the same as those for the PMD31 pressure reducing valve (pages 21 and 22).
Please refer to them.