| Target laws and regulation | periodic self-inspection |
| Industrial Safety and Health Act | Once within a year (Small Pressure Vessel) Once with in a month (Class 1 Pressure Vessel) |
| Ordinance on Safety of Boilers and Pressure Vessels |
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| Aticle 94-94 (Small Pressure Vessels(Autoclave)) |
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| Article 67 （Class 1 Pressure Vessel)） |
|
| Industrial Safety and Health Act | Once within a year |
| Ordinance on Industrial Safety and Health |
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| Article 141 （Centrifuge and Centrifugal Concentrator） |
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| Rules of the National Personnel Authority 10-4 (Site in Japanese) |
Once within a year |
| Article 32 |
Pressure vessels, including boilers, are divided into appropriate types by size.
The differences between Class 1 pressure vessels and small pressure vessels are described as follows in Article 1 of the Enforcement Order of the Industrial Safety and Health Act.
5. Type 1 pressure vessels
Class 1 pressure vessels shall be defined as vessels (excluding those vessels used at a gauge pressure of 0.1 MPa or less with an inner cubic volume of 0.04 m3 or less or with an inner diameter of 200 mm or less and the length 1,000 mm or less and having the product of the maximum operating gauge pressure expressed in MPa multiplied by the internal cubic volume expressed in m3 are 0.004 or less) listed in the following:
A: Of the vessels heating solids or liquids by receiving vapor or other heat media or by generating vapor, those having an internal pressure exceeding the atmospheric pressure (excluding vessels listed in items (b) or (c));
B: Of the vessels generating vapor by chemical, nuclear or other reactions, those having an internal pressure exceeding the atmospheric pressure;
C: Of the vessels for generating vapor by heating liquids contained therein to separate components of the said liquids, those with an internal pressure exceeding the atmospheric pressure;
D: In addition to the containers listed in (A) to (C), vessels containing liquids at a temperature exceeding their boiling points at the atmospheric pressure.
6. Small-sized pressure vessels
"Small-sized pressure vessel" shall be defined as class-1 pressure vessels according to the following:
A: Of the vessels used at a gauge pressure of 0.1 MPa or less, those with an internal cubic volume of 0.2 m3 or less or with drum having an inner diameter of 500 mm or less and the length of 1,000 mm or less;B: The vessels of the product of the maximum operating gauge pressure expressed inMPa multiplied by the internal cubic volume expressed in m3 are 0.02 or less.
In other words, among the Class 1 pressure vessels (those generating vapor above atmospheric pressure in the vessel), those that meet the following conditions are classified as small pressure vessels.
-Maximum working pressure (gauge pressure) is 0.1 MPa or less
-Internal volume 0.2 cubic meter or less
Items to be inspected forClass 1 pressure vessels, according to Ordinance on Safety of Boilers and Pressure Vessels:
-Damages in the body
-Wears in the lid tightening bolt
-Damages in the tubes and valves
Items to be inspected for small pressure vessels, according to Ordinance on Safety of Boilers and Pressure Vessels:
-Condition of the body (damaged/worn or not)
-Damages or wears in the lid tightening bolt
-Damages or wears in the tubes and valves
Items to be inspected for power-driven centrifuge machine according to the Ordinance on Industrial Safety and Health:
-Abnormalities in rotor
-Abnormalities in the bearing parts of the main shaft
-Any brake problems
-Abnormalities in the outer frame
-slackness of a bolt used in the parts of each item previously listed
When these periodic self-inspections are conducted, it is stipulated that the results be recorded and stored for 3 years.
