Patent infringement or not?

Ive been working a tool / encloser for a specific piece of equipment used in the nuclear field . Prior to filing for a provisional patent I found that a company has a patent on a encloser such as mine but its contruction is very specific that being a tent or cloth material . My devise is constructed of hardened materials such as steel and plastic to provide a hardened safety barrier where theirs does not . My devise would do a couple of things their devise does but will go even further to to provide a safety barrier , but they are both enclosers for a specific piece of equipment . Would I be infringing on their patent by building and selling mine given its built from hardened materials an not a "tent"...