RJ21MW series self-operated regulating valve is an air pressure internal setting control valve with a bellows balance structure, designed exclusively for post-valve control.

This internal setting design is a significant departure from traditional pilot-operated pressure regulating valves, offering much better control stability. It features an integrated commander and eliminates the need for the primary pressure reduction and throttling devices commonly found in pilot-operated valves. Pressure adjustment is simplified with a single regulating nut, making it easier to set and maintain.

Design features    >>>

1. Safety overload protection: Effectively unloads overload pressure under abnormal conditions, preventing valve damag；

2. Stainless steel actuator: This option enhances the valve's appearance, prevents rust, and improves its stability and longevity;

3. Packing-free design: The valve body and bonnet structure are compact, reducing the overall size of the valve;

4. Bellows balanced type: The valve core features a bellows balance design, offering low resistance, corrosion resistance, and high-temperature tolerance. This design minimizes unbalanced forces caused by pressure differences, ensuring excellent pressure difference resistance and control accuracy;

5. Modular design: Versatile and easy to replace parts;

6. High precision: The pressure reducing valve and the main control valve operate independently without interfering with each other, ensuring more stable control. The fixed net difference created by the spring action during high-pressure control is minimal compared to the control pressure, allowing for very high control accuracy. This pressure regulating valve is ideal for medium and low-pressure control applications, offering exceptional precision due to the minimal spring-induced net difference;

7. Internal setting design: No external pipe design pressure is needed. The valve connects directly to the pipeline and is ready for use;

8. Visual stroke: The design features scale lines on the top of the membrane head so that the opening and closing travel of the valve core can be observed directly;

9. Low pressure differential design：The bellows-balanced valve core ensures the valve has high resistance to pressure differences and high sensitivity;

10. Single setting nut: A single nut on the main control valve allows for easy pressure regulation through a screw adjustment mechanism, making the process faster and more convenient;

11. Low starting differential pressure: The double membrane head, equipped with a low-stiffness spring, ensures extremely low starting differential pressure, making it suitable for low-pressure differential and high-flow applications.

Application fields    >>>

☼Chemical industry ☼Petroleum industry ☼Electricity industry ☼Pharmaceutical industry ☼Metallurgical industry ☼Food industry ☼Others

Execution standard    >>>

Design criteria：ASME B16.34、GB/T 12224-2015

Structural length：IEC60534-3-1-2001、GB/T 12221-2005

Leakage rating：ANSI B16.104、GB/T4213-2008

Connection standard：ASME B16.5、GB9113、JB79.1~4、HG20592

Product parameters    >>>

Main components and materials    >>>

Structural characteristics     >>>

1. Single setting nut design: It is only necessary to adjust the nut to set the pressure, eliminating the need for throttle valve and primary pressure-reducing valve. This makes the setup and adjustment process quick and convenient.

2. Diaphragm actuator: It adopts a double diaphragm design with overload protection. This design allows it to accurately and sensitively detect changes in medium pressure, improve the response speed and control accuracy of the valve. It also contributes to a longer service life.

3. Travel indicator: It shows the working status of the pressure regulating valve and helps analyze the responsiveness, sensitivity or fluctuation.

4. Set pressure reducing valve: Designed using the lever principle, the set pressure reducing valve is highly sensitive.