Pressure reducing valve - Direct Acting for steam - REH20-M | Miyawaki

Miyawaki REH20-M Direct-Acting Pressure Reducing Valve for Steam

The Miyawaki REH20-M is a self-actuated pressure reducing valve designed for high-pressure and high-temperature steam applications. The downstream pressure is detected within the internal control chamber, directly adjusting the valve opening. No external energy, pneumatic actuator, or impulse line is required.

Technical Specifications

• DN15–DN100.
• Flanged connection, DIN standard.
• Body: cast steel G17CrMo 5-5 / 1.7357.
• Body classes: PN63 and PN100.
• PMA: 6.3 MPa for PN63, 10.0 MPa for PN100.
• TMA / TMO: up to 530°C.
• PMO: 5.7 MPa for PN63, 8.4 MPa for PN100.
• Kvs: 1.8–80 m³/h, depending on DN.
• Maximum pressure reduction ratio: 25:1.

p2 Adjustment Ranges

Standard secondary pressure ranges are 0.05–0.1 / 0.1–0.16 / 0.16–0.25 / 0.25–0.4 / 0.4–0.63 / 0.63–1.0 / 1.0–1.6 MPa. For p2 below 0.05 MPa or above 1.6 MPa, technical confirmation of spring, DN, and sizing is required.

Construction and Operation

The valve is piston-operated, with O-ring sealing and no diaphragm. The conical disc rotates freely at 360°, preventing wear concentration on a single point. Additional gauges, special connections, and soft sealing for leakage class VI are available.

Applications

Used in high-temperature steam reduction stations, power plants, chemical and petrochemical processes, ships, food/beverage, and compact steam equipment with medium or high flow rates.

Selection Criteria

Selection requires p1, p2, steam flow rate, temperature, DN, Kvs, flange PN, allowable reduction ratio, and seat leakage requirement. For reduction ratios exceeding 25:1, two-stage reduction is considered.