Red Seal Gasfitter — Class B Practice Exam

The term "venturi effect" refers specifically to the reduction in pressure that occurs when gas flows through a constricted section of pipe. This phenomenon is based on the principles of fluid dynamics, where a fluid's speed increases as it passes through a narrower area, resulting in a decrease in pressure.

In practical applications related to gasfitting, understanding the venturi effect is crucial for the proper functioning of various gas appliances such as burners and gas meters. When gas passes through a constriction, it speeds up, and due to the principles described by Bernoulli’s equation, this speed increase is accompanied by a drop in pressure. This can be critical in ensuring that an appliance operates correctly and efficiently.

While the other options might relate to different aspects of gas behavior or measurement, they do not accurately capture the specific phenomenon described by the venturi effect as it pertains to gas flow in pipes. Thus, recognizing how pressure changes during gas flow through a constricted area is fundamental for anyone working in gasfitting, especially in ensuring proper installations and safe operations.