Specifies the requirements for the operation of boilers, including unattended, limited attendance and fully attended. It includes the special features within the control, management and supervision systems, associated valves and fittings, housing and installation for those boilers operating in the unattended or limited attendance modes.

This Standard specifies the requirements for the operation of boilers, including unattended, limited attendance and fully attended. It includes the special features within the control, management and supervision systems, associated valves and fittings, housing and installation for those boilers operating in the unattended or limited attendance modes. It also details the checking, testing and maintenance requirements for each category of attendance. The details and limits on the type, design criteria, and usage of unattended, limited attendance and attended boilers to which this Standard is intended to apply are as follows: (a) Boilers for fixed land installations. (b) Boilers having a design pressure as shown in Table 1. (c) Boilers having a power output within the capacity specified in Table 1 for the boiler type and category. (See Note 1.) (d) Boilers complying with the supervision and maintenance requirements specified in Table 1 for the boiler type and category. (e) Boilers for the generation of steam, or other vapour, for which duty the types of boilers permitted are— (i) water-tube type electric type or small boiler types (see Table 1) for unattended operation; (ii) any type of boiler for limited attendance operation (see Table 1); and (iii) any type of boiler for attended operation (see Table 1). (f) Boilers for the heating of water or other liquids at a pressure above that of the atmosphere and to a temperature not less than the normal atmospheric boiling temperature of the liquid, for which duty any type of boiler complying with AS 1228 is permitted for unattended operation, provided that for other than water-tube and electric type boilers, steam or vapour is not generated in the boiler and the boiler drum or shell is fully flooded. (g) Boilers having any of the following sources of energy input:(i) Gas fuel (mains or other gases).(ii) Oil fuel with a closed flashpoint greater than 23°C.(iii) Solid fuels, including solid-fuel-in-suspension.(iv) Waste heat fluids.(v) Electric power.(vi) Solar energy.NOTES:1 This Standard may also be applied to boilers outside the limits specified in Items (a) to (g) where equivalent safety and reliability are required by the owner. 2 Except for definitions in Clause 1.3, other clauses in the Standard refer to steam and water only. The Standard may be applied to other fluids with attention by the owner to the owner’s duty of care to the operational personnel and the general public.

First published as AS 2593-1983.Second edition 1990.AS 3653 first published in 1993.Third edition 1995.Fourth edition 2001.AS 2593-2001 and part of AS 3653-1993 revised, amalgamated and redesignated as AS 2593-2004.Reconfirmed 2016. First published as AS 2593-1983 and part of AS 3653-1993. Previous edition AS 2593-2001. AS 2593-2001 and part of AS 3653-1993 revised, amalgamated and redesignated as AS 2593-2004. Reissued incorporating Amendment No. 1 (February 2007).