Schroeder Valves is offering a new type of valve for pressures from 140 to 250 bar – the Schroeder Intermediate Pressure Valve (SIP).
This series is ideal in systems with frequent operation in the minimum flow range.
It will especially be in use with boiler feed water circuits in gas and steam combined cycle power plants (CCPP) for the protection of centrifugal pumps. Initial projects in pulp mills and other power plants are already being implemented.
In the past decade, the operating mode of power plants has changed considerably.
Historically, process operation was almost exclusively carried out close to the nominal load point of the plants; an area in which the bypass of the minimum flow valve is closed.
Now, cases are increasing rapidly with significantly varying load conditions down to the single-digit percentage range of the nominal load which then has to be compensated.
Previously, it was difficult to prevent cavitation during regular operation and increasingly difficult when operating just below the minimum flow rate in the critical range.
Now, the SIP will be able to operate in this range, even in the area of the switch point hysteresis.
The technical innovations that make the valve unique are found in the main direction of the process medium and the design of the bypass or piston.
In the main process direction, the volume flow-controlled cone utilises a special design.
In the bypass, the SIP controls the bypass with a multi-stage piston, which enables a defined multi-stage pressure reduction at all flow rates and ensures cavitation-free operation at all times.