The PSC Difference Convenient: (15) locations and counting with (11) located in the St. Louis Metro Area alone. Professional: Our tagline “Professionals Serving Professionals” expresses our commitment to serve our customers with a high degree of acumen and a deep sense of duty. PSC employees have over 1000 years of combined experience. Comprehensive: Stocking more than 10,000 SKU’s, PSC maintains the widest and largest array of plumbing supplies in the St. Louis Metro Area. Fast: With a fleet of vehicles, centralized dispatchers, and 24-hour staffing, PSC gets your material to the jobsite, FAST. Flexible: PSC operates a 24-hour Distribution Center and an online webstore to quickly meet the fast-changing needs of both our Missouri and Illinois customers. Stable: Founded in 1924, we are a family business with over 90 years and 4 generations of consecutive family-operation.