Thank you for your interest in our Precast Concrete Storm Shelters all of which are certified to meet the National Storm Shelter Association Standard. Let us tell you a little bit about our company. We are a family owned business that has been in operation since 1962. Our President, Mike Vaughn, is a registered Professional Engineer licensed in ... Precast Concrete Pipe Forms. Del Zotto Products of Florida manufactures pipe forms ranging in size from 12 to 96 ID for A, B and C wall thicknesses, dry-cast or wet-cast. Del Zotto can make single, dual and quad dry-cast forms for sizes 12 through 24 ID.