May I ask whether a PP-lined manhole with a diameter of 500 must have an opening of 450? It says that people need to go in for spark testing
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May I ask whether a PP-lined manhole with a diameter of 500 must have an opening of 450? It says that people need to go in for spark testing
A DN150 manhole can be installed
It is over 3 meters tall and has end caps at the top and bottom; does one have to go inside in order to perform spark testing?
(1) For water-tube boilers with a drum inner diameter of 800 mm or more, and shell-and-tube boilers with a drum inner diameter of 1000 mm or more, manholes shall be provided on the cylinder or the head (tube sheet)； For shell-and-tube boilers with a drum inner diameter of 800–1000 mm, at least one head hole must be provided on the drum or the head (tube sheet). (2) For pressure vessels with an inner diameter of ≥1000 mm, at least one manhole shall be provided ； For inner diameters ranging from <1000 mm to ≥500 mm, one manhole or two handholes shall be provided. For inner diameters of <500～≥300 mm, at least two manholes shall be provided. The dimensions of openings in the pressure-bearing components of the boiler shall comply with the following provisions: