Welcome - Sproule Mfg. Co., Inc 3239 Phoenixville Pike, PA 19432 Devault Ph: (610) 647-5687 2260 Appelt Drive, Houston77015 Ph: (281) 860-9950 Sproule Manufacturing Company, Inc started manufacturing Perlite Silicate Pipe & Block Insulations in 1977 as a subcontractor to a Wilmington, Delaware firm with manufacturing rights to a Patent held by E.I. DuPont Co. The quality control of these products was so poor that breakage in shipments and handling limited its acceptance. In 1979 we requested, and were granted, a license to manufacture Perlite Silicate Pipe & Block Insulations by DuPont Company. Our first order of business was to improve and upgrade the quality of the existing product. We developed a new formula and started producing an acceptable product with better physical and thermal properties in 1980. In the years following, we have added the first water repellent Perlite Silicate Insulation in the thermal insulation industry, R-1200 Perlite Pipe & Block, specialty items such as 90 & 45 elbows, T's, flange covers, and valve covers. In 1995 we opened our Houston, Texas warehouse. In conjunction with Extol of Texas (now SPI/Extol) we hit the ground running with over 1, 000 perlite elbows in the Gulf Coast market. By 1997, we required a larger warehouse to handle the demand for our High Temperature Pre-Molded Perlite Fitting Covers.