Mandan Mechanical Contractors 2716 34th St NW JH Kelly, Serving the construction industry for over 80 years, is a privately owned, self-performing contractor specializing in virtually every aspect of mechanical and electrical construction. Mandan ND Mechanical Contractors J H Kelly Mechanical Contr www.jhkelly.com JH Kelly LLC mechanical industrial high tech semi-conductor enviromental cleanup remediation pulp paper oil refinery commercial steel condensate steam generation pipefitting welding millwright plumbing concrete hvac boilers contr JH Kelly LLC mechanical industrial high tech semi-conductor enviromental cleanup remediation pulp paper oil refinery commercial steel condensate steam generation pipefitting welding millwright plumbing concrete hvac boilers contr Business Reviews J H Kelly Mechanical Contr Testimonials