Can a vent pipe be directly connected to the flue on gas equipment?

The correct response is that a vent pipe must not be directly connected to the flue on gas equipment due to safety and regulatory compliance reasons.

Flue systems are designed to handle the byproducts of combustion, while vent pipes are typically intended for venting exhaust gases from appliances to the outside atmosphere. Connecting these two systems directly could lead to backdrafting or leakage of harmful gases into occupied spaces, compromising safety.

Additionally, building codes and gas appliance regulations often dictate specific configurations for venting to ensure that exhaust is effectively removed while preventing any potential hazards. It is crucial that appropriate connections and fittings, which meet all safety standards, are used in the venting process, thus necessitating the use of special adapters or specific methods as defined by manufacturer specifications and local codes.