Both high- and low-pressure boilers heat water or steam in an enclosed vessel, which then exits the boiler for various processes or heating applications. A hot water system boiler uses a pump to circulate the hot water, while the steam boiler uses its own pressure to circulate the steam throughout the system. Boilers can be fueled by various sources including electricity, natural gas, or oil.
ANSI Z21.13-2010/CSA 4.9-2010, Gas-Fired Low Pressure Steam and Hot Water Boilers, a recently published standard from ANSI organizational member and accredited standards developer CSA America, provides guidelines for safe operation, substantial and durable construction, and acceptable performance of gas-fired low-pressure steam and hot water boilers. This standard applies to newly produced gas-fired low-pressure steam and hot water boilers with gas inlet pressure ratings not exceeding 1/2 psi (3.5 kPa) and having input ratings of less than 12,500,000 Btu/hr (3,663,389 W), constructed entirely of new unused parts and materials, for operation at or below the specified pressures and temperatures for use with natural gas, manufactured gas, mixed gas, liquefied petroleum (LP) gases, and LP gas-air mixtures.
CSA America is a non-profit organization dedicated to the creation and promulgation of standards for gas appliances and accessories and alternative energy products. CSA standards serve businesses, trade associations, governments, and industries in the U.S. and the global marketplace in order to enhance public safety, advance the quality of life, help preserve the environment, and facilitate trade.