Final answer:
Type B double wall gas vent pipe should not contact combustible materials even though it has a double wall designed to handle hot gases and stay cooler, to prevent the risk of fire.
Step-by-step explanation:
The statement, Type B double wall gas vent pipe may be allowed to contact combustible materials, is False. Type B double-wall gas vent pipe is a special venting system designed for gas-burning appliances like furnaces and water heaters. Although it has two walls—an inner one, which is designed to handle the hot gases, and an outer one, which is designed to stay cooler—it should still not be in contact with combustible materials. Sufficient clearances between critical vent components and combustible materials are necessary to prevent the risk of fire.
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