Large commercial pressure cookers are available at PressureCooker-Outlet.com, WebstaurantStore.com, eBay.com and Amazon.com, as of March 2015. The most common size is 14 quarts or smaller to prepare meals, but commercial canning pressure cookers are available in 23-quart sizes.
The most common brands are Presto and Chef's Design, with the latter selling 10.6-quart units from Pressure Cooker Outlet. The Presto models on eBay hold 23 quarts, and restaurants use them to prepare food for storage, but cooks can use them to prepare large meals.
Amazon.com's selection includes Kuhn Rikon and MIU France models, both of which hold 8 quarts. WebstuarantStore offers a 14-quart commercial-grade pressure cooker.