CSA 7.2:2013 pdf download.Gas clothes dryers, volume II, type 2 clothes dryers
4.1.2 Every part of the dryer shall be of such construction as to be secure against displacement, distortion, warping or other damage and shall be constructed so as to maintain a fixed relationship between essential parts under normal and reasonable conditions of handling and usage. Parts not permanently secured shall be designed so that they cannot be improperly located when removed and replaced during cleaning or other servicing.
4.1.10 The dryer shall be provided with an interlock which will be automatically actuated when the loading door is opened not more than 3 in (76.2 mm) while the dryer is in its normal operating cycle. This interlock shall function both to stop the drum rotation and shut off the main burner gas supply within 10 seconds.When closing the loading door, this interlock shall not permit the drum to rotate or the main burner gas to turn on until (1) the door is closed to 3 in (76.2 mm) or less, and (2) a secondary function control, manually operated from outside the dryer, is actuated.
4.2 Accessibility
Thermostats, orifices, burner ignition devices, burners and controls which may require cleaning,lubrication or adjustment in the field shall be accessible from the front or rear of the dryer without disconnecting the dryer from the gas supply. No special tools shall be required for making adjustments. Removal of access panels is permissible. Access panels may be locked.
4.4.1 Structural sheet-iron or steel parts, if unfinished and not in contact with flue gases, shall be at least 0.0195 in (0.495 mm) thick. Structural sheet-metal parts fabricated from corrosion-resistant metal or alloys, or structural sheet-steel or iron parts finished in porcelain enamel or otherwise finished, shall be equal to the strength and durability of 0.0195 in (0.495 mm) thick sheet steel, except that such sheet metal shall be at least 0.0152* in (0.386 mm) thick. Ornamental and finishing strips need not comply with this provision.
This corresponds to No.26 U.S. Standard for gage sheet steel with all applicable minus tolerances included.
4.5.5 Joints used in the pressure zone or in the burner head of a burner assembly shall be gastight and shall not depend for mechanical strength or primarily for tightness on set screws, cement or other sealing materials, except where such joints form part of the port area. The burner head shall be a single casting,or the joints shall be welded, brazed, bolted, be of screw-joint construction or of an equally rigid and gastight construction. Pipe used in burner construction shall be at least the weight of standard wrought steel pipe as defined in the Standard for Welded and Seamless Wrought Steel Pipe, ANSI/ASME B36.10M.
4.5.6 Ports shall be machined or otherwise accurately made in submitting the dryer for test; the manufacturer may furnish a list of manufacturing tolerances applicable to the burner and have the dryer tested for compliance with this standard in both extremes of tolerance specified.CSA 7.2 pdf download.