servoattuatori “low pressure” Duplomatic MS

---

---

Today, we discuss a very unique application: servo actuators operating at low pressure, below 6 bar!

This involves the revamping of an old steam power plant with control valves operating with lubrication oil derived from the turbine bearing lubrication system, where the relief valve is set at 6 bar. This leads to two important considerations:

1. The actuators must have as little friction as possible.
2. The proportional valves must be direct-acting due to the unavailability of the minimum pilot pressure, and they must have limited pressure loss.

The first consideration, regarding reduced friction, guides the designer towards using helical springs instead of the traditional cup springs typically used in single-acting servo actuators. This is feasible given the short strokes of the control valves, around 20 mm.

As for the choice of the proportional control valve, the fluid flow rates in transit, considering the required actuation times of 1.5 seconds, allow the use of direct-acting DN6 valves. A technical assessment was carried out to determine the configuration of the spool to minimize pressure losses while maintaining adequate flow control for the required positioning precision.

The result fully satisfied the end user as the project not only met the functional specifications but also demonstrated a significant functional margin, with all actuators achieving performance at pressures below 4 bar. Therefore, even in the event of unforeseen pressure drops in the lubrication system, the functionality of the plant is ensured.

Another success for Duplomatic MS in the energy sector.

Tag

• #Industry
• # Servo Actuators

---

---

Share

---

---

Latest News

---

---