Pressure manways, as a category focusing on the pressure parameter, include products of various shapes. So among the pressure manways, we find round manways, oval manways and rectangular manways.
The shape of the manway for pressure applications plays a key role. The pressure manways with the highest technical specifications are:
- round manways,
- oval manways.
Round pressure manways are typically characterized by more handwheels installed around the perimeter of the manway compared to their non-pressure counterparts. In addition, round pressure manways are accompanied by a thicker wall of the lid and manway frame. The combination of these features results in increased overall pressure resistance of the design.
In the case of oval manways, factors affecting increased pressure resistance include frame wall thickness, lid thickness, and locking system design. In addition, oval manways frequently have a lid that opens inwards into the tank. As a result, the manway lid is naturally pressed around the perimeter of the frame by a force acting on it from the inside.
Rectangular pressure manway lids, due to their technical characteristics, are usually used for less demanding pressure applications. The pressure resistance of rectangular manways does not usually exceed 2.5 bar.