Gaskets used on gas flanges must be full-faced and be made of which materials?

Gaskets used on gas flanges must be full-faced and be made of which materials?

• A. Rubber and neoprene
• B. Aluminum and steel
• C. Bronze and cast iron
• D. Copper and brass

Answer: (C)

In fuel-gas piping, flange joints must seal across the entire face to prevent leaks under pressure. That’s why gaskets used on gas flanges are full-face—covering the whole mating surface so bolt load is evenly distributed and any minor surface imperfections are sealed. The materials specified for these gaskets are bronze or cast iron because they provide a durable, gas-compatible metal seal that stands up to fuel gases and the temperatures and pressures involved. Elastomeric or softer metals, like rubber or neoprene, can deteriorate, swell, or permeate with hydrocarbons and aren’t as reliable for long-term gas service. Materials such as aluminum, steel, copper, or brass don’t offer the same combination of rigidity, chemical compatibility, and sealing performance required for fuel-gas flange joints. Bronze and cast iron are chosen for their stability and seal integrity in this application.

In fuel-gas piping, flange joints must seal across the entire face to prevent leaks under pressure. That’s why gaskets used on gas flanges are full-face—covering the whole mating surface so bolt load is evenly distributed and any minor surface imperfections are sealed.

The materials specified for these gaskets are bronze or cast iron because they provide a durable, gas-compatible metal seal that stands up to fuel gases and the temperatures and pressures involved. Elastomeric or softer metals, like rubber or neoprene, can deteriorate, swell, or permeate with hydrocarbons and aren’t as reliable for long-term gas service. Materials such as aluminum, steel, copper, or brass don’t offer the same combination of rigidity, chemical compatibility, and sealing performance required for fuel-gas flange joints. Bronze and cast iron are chosen for their stability and seal integrity in this application.