Bronkhorst In-Press P-800 Closed system pressure controller
Principle of operation
The Process Pressure Controller consists of a piezo-resistive pressure sensor
and two direct acting, solenoid control valves. The instrument has a gas
inlet for pressurisation, a pressure relief outlet and a system outlet.
While pressurizing the system – this will normally be a static volume –
the pressure sensor and the inlet valve operate as a forward pressure
controller and the relief valve remains shut. When the system requires
depressurisation, the inlet valve is shut and the pressure sensor in
combination with the relief valve will act as back pressure controller.
This dual valve construction is a compact, economical alternative to
configurations where forward pressure controllers are combined with separate
bleed ports and relief valves. It is considered as a great advantage that the
relief valve does not continuously vent to the atmosphere. Furthermore the
system can be set for either fast or smooth controlled (de)pressurization.
Dome loaded pressure regulators are often used to process aggressive reactants and by-products at high temperatures.
For these severe applications, dome valves can be manufactured from chemically inert materials such as SS316, Hastelloy, Zirconium and Monel.
For the automation of dome loaded back pressure regulators, P-8x2I instruments can be applied to control the position of the membrane to open or close
the orifices of the dome loaded regulator, thereby releasing gas or liquids from the process as to keep the process pressure at a constant level.
