What piping material is specified to be used for venting regulators?

The correct answer is PVC (polyvinyl chloride), as it is commonly specified for venting regulators due to its properties that make it suitable for venting applications. PVC is resistant to various chemicals, does not corrode, and can withstand the pressures typically associated with venting. These characteristics ensure that the venting system remains intact and functional, minimizing the risks associated with gas venting.

In addition to its physical properties, PVC is widely available and easy to work with for installation purposes. This makes it a preferred choice in many plumbing and gas applications where a reliable venting solution is necessary. While other materials like CPVC, PE, and ABS may have their applications, they do not typically meet the specific requirements for venting regulators as effectively as PVC does. For instance, CPVC is often used for hot water applications, PE is usually associated with underground piping for gas or water, and ABS is primarily used for drain, waste, and vent systems. Thus, PVC stands out as the most appropriate material for this specific purpose in compliance with the National Fuel Gas Code.