The Natural Gas company I work for is installing 2- 208V gasoline pumps at or shop. They want me to install a 100A sub-panel out near the pumps to feed them electrical power. My question is how close to the pumps can I put the sub-panel. I plan on useing all ridgid conduit, but should all fittings and boxes be explosion proof with seal-offs? I guess I should read up on my Class and division areas.