ABSTRACT
This chapter discusses the byelaws related to the prevention of waste or contamination of water from any hot water system. According to byelaw 89, no vent pipe from any secondary system shall be connected to or arranged to discharge water into any combined feed and expansion cistern connected to a primary circuit. Byelaw 91 ensures that installations of mains fed secondary water heating apparatus shall have a means of accommodating the expansion water. According to byelaw 93, every boiler shall be constructed of materials the nature, strength and thickness of which is capable of withstanding the internal water pressure and operating temperature to which it is, or is likely to be, subject. The requirements of byelaw 94 would be accepted as being satisfied if every expansion or pressure relief valve complies with British Standard 6283. Under normal conditions of operation, expansion of water on heating up is catered for by measures dealt with in byelaws 90 to 92.
