Boilers are divided into steam boilers, hot water boilers, heat carrier boilers and hot blast furnaces according to the heat transfer medium. The boilers regulated by the “Special Equipment Safety Law” include pressure-bearing steam boilers, pressure-bearing hot water boilers, and organic heat carrier boilers. The “Special Equipment Catalog” stipulates the parameter scale of boilers supervised by the “Special Equipment Safety Law”, and the “Boiler Safety Technical Regulations” refines the supervision forms of each link of boilers within the supervision scale.
The “Boiler Safety Technical Regulations” divides boilers into Class A boilers, Class B boilers, Class C boilers and Class D boilers according to the degree of risk. Class D steam boilers refer to steam boilers with rated working pressure ≤ 0.8MPa and planned normal water level volume ≤ 50L. Class D steam boilers have fewer restrictions on design, manufacturing, and manufacturing supervision and inspection, and do not require pre-installation notification, installation process supervision and inspection, and use registration. Therefore, the investment cost from manufacturing to putting into use is low. However, the service life of D-class steam boilers shall not exceed 8 years, modifications are not allowed, and overpressure and low water level alarms or interlock protection devices must be installed.
Steam boilers with planned normal water level volume <30L are not classified as pressure-bearing steam boilers under the Special Equipment Law for supervision.
It is precisely because the dangers of small steam boilers with different water volumes are different and the supervision forms are also different. Some manufacturers avoid supervision and rename themselves steam evaporators to avoid the word “boiler”. Individual manufacturing units do not carefully calculate the water volume of the boiler, and do not indicate the volume of the boiler at the planned normal water level on the planning drawings. Some unscrupulous manufacturing units even falsely indicate the volume of the boiler at the planned normal water level. Commonly marked water filling volumes are 29L and 49L. Through testing the water volume of non-electrically heated 0.1t/h steam generators manufactured by some manufacturers, the volumes at normal water levels are all exceeding 50L. These steam evaporators with actual water volumes exceeding 50L require not only planning, manufacturing supervision, installation, Applications also require supervision.
Steam evaporators on the market that falsely indicate a water capacity of less than 30L are mostly made by units without boiler manufacturing licenses, or even by riveting and welding repair departments. The drawings of these steam generators have not been type-approved, and the structure, strength, and raw materials have not been approved by experts. Admittedly, it is not a stereotyped product. The evaporation capacity and thermal efficiency indicated on the label come from experience, not energy efficiency testing. How can a steam evaporator with uncertain safety performance be as cost-effective as a steam boiler?
A steam evaporator with a falsely marked water volume of 30 to 50L is a Class D steam boiler. The purpose is to reduce restrictions, reduce costs, and increase market share.
Steam evaporators with falsely marked water filling volumes avoid supervision or restrictions, and their safety performance is greatly reduced. Most of the units that use steam generators are small enterprises with low operation management capabilities, and the potential risks are extremely high.
The manufacturing unit falsely marked the water filling volume in violation of the “Quality Law” and the “Special Equipment Law”; the distribution unit failed to establish special equipment inspection, acceptance and sales record standards in violation of the “Special Equipment Law”; the user unit used illegal production, without supervision and inspection, and Registered boilers violate the “Special Equipment Act”, and the use of boilers manufactured by unlicensed units is classified as non-pressure boilers for pressure use and violates the “Special Equipment Act”.
A steam evaporator is actually a steam boiler. It is just a matter of shape and size. When the water capacity reaches a certain level, the risk will increase, endangering people’s lives and property.