Raw product from the balance tank is transported by a Waukesha positive displacement feed pump to the product heater. After the WCB corrugated tubular heat exchangers heat the product to processing temperature, the product may be held in a holding tube for a predetermined amount of time. From the holding tube or heater, the product flows to the filling machine. If necessary, the product is cooled to the desired filling temperature using WCB corrugated tubular heat exchangers as regenerators or coolers. The unfilled product is returned to the balance tank. The returning product may be cooled to lower holding temperature using WCB corrugated tubular return (“divert”) cooler heat exchangers.