The Series 500 is a four-pass, wet-back scotch-type boiler, available in steam or hot water versions. The four-pass wet-back design eliminates refractory baffles between flue gas passes; there are no refractory doors to replace or maintain, reducing maintenance, says the company. Built for optimum fuel efficiency, the fourth pass extracts every Btu of spent energy that would otherwise be vented to the stack of dry-back boilers, the company says. Firing gas, oil, or combination gas/oil, the boilers are offered in sizes from 100 to 1,500 bhp, with pressures to 250 psig.
Hurst Boiler & Welding Co., Inc., P.O. Box 529, Highway 319 N., Coolidge, GA 31738; 877-994-8778 or 229-346-3545; 229-346-3874 (fax); www.hurstboiler.com (website).