1) The turbine bolt electric heater shall meet the following requirements:

1. The raw materials used for the electric heater shall meet the following requirements:

① The composition of the insulating material magnesium oxide shall comply with the provisions of HG3-1294-80 "Magnesium Oxide";

② Magnesium oxide must be dried before use;

③ The heating material used for the electric heater is 0Cr27A17Mo2 high-resistance electric heating alloy wire, with an operating temperature of 400°C, and technical requirements according to GB1234 "High-Resistance Electric Heating Alloy";

④ The material of the protective tube for the electric heater is 1Cr18Ni9Ti heat-resistant stainless steel tube. Its technical requirements shall comply with YB804 "Stainless and Acid-Resistant Steel Seamless Tubes". The use of other materials shall be agreed upon between the manufacturer and the user;

⑤ The inside of the protective tube used for the electric heater shall be deburred, then cleaned with gasoline or kerosene, and dried before use.

2. The finished electric heater shall meet the following requirements:

① The rated working voltage of the electric heater is 220±20V. DC 100V, low voltage 50V;

② For insertion length within 1m, the straightness of the centerline shall not exceed ?0.3mm; for insertion length between 1-2m, the straightness of the centerline shall not exceed ?0.4mm;

③ The diameter deviation of the insertion part is -0.20mm/-0.50mm;

④ The length deviation of the insertion part is ±5mm, the heating length deviation is ±5mm, and the cold end length at the bottom is 25-30mm;

⑤ The electric heater shall heat evenly during use, and local overheating is not allowed.

(2) When performing a life test on the electric heater, each heating time is 10-20min. Under intermittent heating conditions, with the total gap between the bolt center hole and the outer diameter of the electric heater being 0.8-1.3mm, the cumulative life shall not be less than 50h.

(3) The connection between the alloy resistance wire and the lead-out wire shall be firm and reliable, without looseness. The shell must be well grounded.

(4) After the steel tube of the electric heater is cold-drawn and reduced, its surface shall be inspected by dye penetrant testing or with a magnifying glass of 5x or more, and there shall be no cracks or other defects. The tube reduction shall be formed in one direction.

(5) The cold end seal of the electric heater shall be tightly sealed to prevent moisture from entering and damaging the insulation.

(6) After the electric heater is manufactured, after one and a half months, its insulation resistance shall be measured again at room temperature with a 500V megohmmeter (can be performed at the manufacturer or user site) and shall not be less than 50MΩ.


Company ProfileYangzhou Darui Electric Heating Appliance Co., Ltd. is an enterprise integrating research and development, manufacturing, online sales, and market sales. The company produces a wide range of products: nickel-chromium wire, iron-chromium-aluminum wire, electric heating flat strip, constantan wire, heating rod, U-shaped (special-shaped) electric heater, finned electric heating tube, flange electric heating tube, quartz electric heating tube, cast heater, mica heater, ceramic heater, electric heating plate, air heater, etc., and designs various electric heating mechanical products for customers. The products are widely used in aviation, shipbuilding, petroleum, chemical, washing, chemical fiber, machinery manufacturing, automotive, motor, radio, instrumentation, plastic, textile, food, printing and packaging, rubber, medical and health, household appliances and other industrial sectors. The company adheres to the consistent and unremitting work principles shared with major manufacturers: meticulous work, strict requirements, quality control, and steady development. Focus on quality, integrity, and one-stop service! The company will, as always, take "excellent quality, first-class service as the purpose", work hard, and ride the tide of the market economy to jointly write the glory of the century. We practice sustainable management with customer satisfaction, employee willingness, and business satisfaction; enhance product competitiveness with innovative quality, guaranteed delivery, affordable prices, and increased productivity; and are committed to developing new products, moving towards diversification and internationalization as our pursuit goals. Our company is located in the rich and beautiful Subei Plain, with the largest tidal flat wetland in the country, and has unique geographical advantages. Highways, railways, aviation, water transport, etc., form a dense and convenient transportation network. We warmly welcome new and old customers from all over the country to visit and patronize. Our company is committed to high-quality pre-sale and after-sale services, providing customers with precision-manufactured equipment and complete technical services. We firmly believe that using our company's products and equipment and the services we provide will bring you satisfactory economic benefits. We wish our cooperation pleasant and fruitful!