Diaphragm for pneumatic controller

A diaphragm to isolate a first chamber of a pneumatic controller from a second chamber of a pneumatic controller comprising:

• a first diaphragm surface;
• a diaphragm opening extending through the diaphragm;
• and
• two fabric reinforcing layers to strengthen the diaphragm;
• and
• a second diaphragm surface opposite the first diaphragm surface, the two fabric reinforcing layers disposed between the first diaphragm surface and the second diaphragm surface;
• wherein the two fabric reinforcing layers are of unequal size;
• wherein at least one fabric reinforcing layer of the two fabric reinforcing layers is disposed at the first diaphragm surface;
• and
• wherein the at least one fabric reinforcing layer covers less than 75% of the first diaphragm surface.

A pneumatic controller, comprising:

• a housing;
• a piston disposed in the housing and movable therein;
• a spring seat disposed at the piston;
• a spring operably connected to the spring seat to bias a position of the piston;
• a bolt extending through the spring seat into the piston to secure the spring seat to the piston;
• a diaphragm interposed between the piston and the spring seat to isolate a first chamber of the pneumatic controller from a second chamber of the pneumatic controller, the diaphragm including:
• a first diaphragm surface;
• a diaphragm opening extending through the diaphragm, the bolt extending through the diaphragm opening;
• and
• two fabric reinforcing layers to strengthen the diaphragm;
• and
• a second diaphragm surface opposite the first diaphragm surface, the two fabric reinforcing layers disposed between the first diaphragm surface and the second diaphragm surface;
• wherein the two fabric reinforcing layers are of unequal size;
• and
• a collar disposed at the spring seat and extending through the diaphragm opening.