Diaphragm Design Manual - Simrit

Flange Radius – See Transition Radii.Flash – The excess material left behind as a result of the molding or trimming operations.Flat Cut – A diaphragm cut from flat sheet material, with or without fabric reinforcement, foruse with low stroke applications.Flex Failure – Any failure due to improper flexing of the diaphragm. This can result fromimproper diaphragm or hardware design, assembly problems or incorrect material choices.Flexing Area – See Convolution and Convolution Width.Four Cornering – See Cornering.Gasketing – Cellulose, fiber, cork and rubber combinations added to the diaphragm for thepurpose of enhancing its sealing properties.Height – This measurement often refers to the distance from the underside of the flange to thehighest point of the convolution and is instrumental in determining the diaphragm’s strokecapability.Hysteresis – As used in physics, the lagging of the effect in a body when the force acting on itis changed.Lay-Up – This is a process for producing a one side coated diaphragm in which the rubber islaminated to the reinforcing fabric in the molding operation. Rubber coverage is typically greateron one side than the other (See Fabric Side).Loading – Refers to the amount of pressure exerted on the diaphragm surface to achieve a seal.Offset Convolution – See Drop Center DiaphragmPermeation – The ability of a fluid to pass from one side of the diaphragm to the other.Pie-Pan Diaphragm – See Dish Diaphragm.Piston Area – This refers to the portion of the diaphragm that will cover the working surface ofthe diaphragm.Piston Cap – A piston cap, sometimes referred to as a Curved Lip Retainer, is a piece ofhardware that attaches to the diaphragm, opposite the piston, to help retain the diaphragm andaid in its convolution movement.Piston Diameter – This refers to the portion of the diaphragm that will fit over the outsidediameter of the piston hardware. This diameter defines the inside diameter of the diaphragm’sconvolution.Piston Radius – See Transition Radii.Piston Skirt – The piston skirt is the extension of the piston that extends 90 o away from its topsurface and aids in forming and supporting the diaphragm sidewall during its stroke.© Copyright FNGP 200949