Measuring Oval & Oblong Manway Doors
Sizing an Oval or Oblong Manway Door
The most important dimension is the circumference:
You can get this dimension by measuring all the way around your door, your old gasket or the flange.
The next dimension is the Cross Section of the long leg.
You can get this dimension by measuring your old gasket, or the distance of overlap from the door to the side of the tank.
The cross section is typically the sealing surface of the gasket - the rubber which is between the door and the tank or the door and the flange.