One: The strength of the organic heat carrier boiler shall be calculated according to the "Strength Calculation of Pressurized Components of Pipe Boilers" standard and the "Strength Calculation of Pressurized Components of Shell Boilers" standard. The design calculation pressure shall be the working pressure plus 0.3 MPa, and not less than 0.59 MPa. Two: Welding and flaw detection of the pressurized components shall comply with the following requirements:

Pipes, kettle drums, collection boxes, and pipelines should be connected by welding.

2. The longitudinal seams, annular seams, and head joint seams of the drum must be welded using submerged arc automatic welding. In cases where tooling limitations are present, the inner side of the annular seam at the back of the drum may be welded manually using an electric arc welding process.

The butt welds on the heating surface tubes of the organic heat carrier boiler should be done using gas shielded welding.

4. The longitudinal welds of the drum and the joint seams of the heads should undergo radiographic or ultrasonic testing, with at least 25% radiographic testing. The butt welds of the heating surface pipes should be subjected to random radiographic inspections, with the number being: not less than 10% of the joint count for the radiation section, and not less than 5% for the convection section. In case of non-compliance during inspections, double the number should be re-inspected.

5. For each batch of 10 gas-phase furnaces, a longitudinal weld inspection test plate is produced (even if there are fewer than 10). Welding inspection test plates are not required for the pot shells and tube-to-pipe joints of liquid-phase furnaces.

The welding process for organic heat carrier boilers should be conducted in accordance with the provisions of the "Regulations for Safe Technical Supervision of Steam Boilers."

When flange connections are required for pressure parts, the flanges should be of a tongue-and-groove design or flat-welded steel type with a nominal pressure (PN) of not less than 1.6 MPa. The gaskets should be made of metal-woven graphite or expanded graphite composite materials.

Section 4: Pressure elements of organic heat carrier boilers and pipeline accessories must not be made of cast iron or non-ferrous metals.

To prevent overheating and decomposition of the organic heat carrier and carbon accumulation in the liquid-phase furnace, it is essential to maintain a flow rate of the organic heat carrier within the heating surface tubes: not less than 2 m/s for the radiant heating surface and not less than 1.5 m/s for the convective heating surface. For the pot shell of horizontal external combustion liquid-phase furnaces, reliable measures should be taken to prevent overheating of the pot shell and premature aging of the organic heat carrier.

Six: The vapor phase furnace with a pot-like chamber should adopt a water-tube boiler structure. The ratio of the sum of the cross-sectional areas of the downcomers to the sum of the cross-sectional areas of the risers should not be less than 40%, as well as the ratio of the sum of the extracted tube cross-sectional areas to the sum of the riser cross-sectional areas. Otherwise, a fluid dynamic calculation should be performed.

Article 7: The supplier of organic thermal carriers should provide reliable physical and chemical property data of the organic thermal carriers, such as high-temperature operating temperature, viscosity, flash point, residual carbon, acid value, etc. Article 8: During the design and operation of organic thermal carrier boilers, the temperature of the organic thermal carrier at the outlet of the boiler must not exceed the operating temperature of the organic thermal carrier.

The structure of the organic heat carrier boiler and the return pipeline should ensure free flow of the organic heat carrier and facilitate the discharge of the organic heat carrier from the boiler.

Ensure that drainage devices are installed at the lower parts of the boiler drum and pipeline network, and the drainage pipes should be connected to a safe location.

Eleventh, fully assembled organic heat carrier boilers should undergo hydrostatic tests at 1.5 times their working pressure at the manufacturing plant. For gas phase furnaces, air tightness tests should also be conducted at the working pressure or system circulation pressure to inspect the sealing conditions of non-welded parts of the organic heat carrier boiler, such as flange connections, manholes, handholes, and inspection openings.

After hydrostatic testing, the water should be drained completely, and nitrogen is recommended for the airtightness test.