Technical field report

Self- acting pressure regulators are so- called relative pressure regulators, as they regulate relative to the atmosphere. The following sectional drawing shows a pressure reducing valve with a breathing hole (marked red), which enables the relative reference to the atmosphere. The breathing hole is used to “suck in” or “push out” the air when the diaphragm moves.

In the event that the diaphragm, which is made of PTFE virgin as standard, breaks or cracks, the media can diffuse through the diaphragm and exit to the atmosphere. Depending on the media flowing through the pressure regulator, caution is required.

Closing the breathing hole is out of the question, as this would impair the general function of the pressure regulator. This means that the safe discharge of the media must be guaranteed in the event of a diaphragm crack.

Zuercher Technik has designed a flat diaphragm housing to prevent the diaphragm from cracking due to overstretching. Furthermore, the diaphragm is protected on both sides by a stainless steel diaphragm plate. This means that only the area between the outer edge of the diaphragm plate and the body seal is free and movable. Possible pressure shocks in the system press the diaphragm against the respective edge only. The diaphragm movement is mechanically limited. Another cause could be material incompatibility with the media. This can attack and damage the diaphragm. For this reason, we produce the pressure regulators with a modified breathing hole. Instead of a simple breathing hole, this valve has a connection with an internal thread to which a pipe can be connected. This pipe can then be routed to a gas scrubber or another safe location. A sensor can also be installed in this blow-off line, which indicates a leakage in the event of a diaphragm crack and provides a corresponding message. The safe and controlled shutdown of that system section is ensured so that the pressure regulator can be repaired.