Diaphragm Design Manual - Simrit

failures that look like cuts perpendicular to the flange.Figure 24 – CorneringCurl – A lifting at the OD of the diaphragm due to unbalanced coating in the coated fabric.Curved Lip Retainer – See Piston Cap.Cylinder Diameter (Bore) – The inside diameter of the cylinder used to define the maximum,or outside, diameter of the convolution.Cylinder Radius – The transition radius between the flange and the cylinder wall.Dish Diaphragm – This diaphragm shape refers to a shallow Top Hat Diaphragm. A dishdiaphragm is often used in applications where a stroke requirement cannot be satisfied by a flatcut diaphragm.Drop Center Diaphragm – This diaphragm shape is similar to a Convoluted Diaphragm but itspiston area surface is located above or below the flange plane to assist assembly, stroke or both.This style of part typically has a slightly greater stroke length than the convoluted style.Effective Area – The area of the diaphragm the pressure acts on. This area normally comprisesthe piston diameter + one convolution width.Exercised -- Broken-In - Example: A regulator diaphragm that is exercised prior to final setpoint adjustment will likely not drift or have to be reset prior to shipment.Fabric Drift – See Bleed through.Fabric Side – On a one side coated diaphragm the fabric side of the diaphragm is the sidewhere the underlying fabric reinforcement is visible. The fabric side must always be located onthe low-pressure side of the system.Flange – The outside portion of the diaphragm beyond the convolution.Flange Diameter – The outside diameter of the flange.© Copyright FNGP 200948