Product Details

1. The raw materials used in the electric heater should meet the following requirements:

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

② Magnesium oxide must be dried before use;

③ The heating material used in the electric heater is 0Cr27A17Mo2 high-resistance electric heating alloy wire, with a working temperature of 400°C, and the technical requirements are in accordance with GB1234 "High-Resistance Electric Heating Alloy";

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

⑤ The electric heater protective sleeve should be deburred internally, then cleaned with gasoline or kerosene, and dried before use.

2. The finished electric heater should 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 should not exceed ?0.3mm; for insertion length of 1-2m, the straightness of the centerline should 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 bottom cold end length is 25-30mm;

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

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

(3) The connection between the alloy resistance wire and the lead wire should be firm and reliable, without looseness. The shell must be properly grounded.

(4) After the steel sleeve of the electric heater is cold-drawn and reduced, it should be inspected by dye penetrant testing or with a magnifying glass of 5 times or more for surface defects such as cracks. It should be formed in one direction during tube reduction.

(5) The cold end seal of the electric heater should 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 should be measured again at room temperature with a 500V megohmmeter (can be carried out at the manufacturer or user's site) and should not be lower than 50MΩ.Test Methods and Acceptance Rules

After each electric heater is assembled, its insulation resistance should be measured at room temperature with a 500V megohmmeter and should not be lower than 50MΩ. It should also withstand a 1500V withstand voltage test for 1 minute without breakdown or flashover. Then, in the air, it should be energized and heated at the rated working voltage for 2-3 minutes, without overheating, and the insulation resistance should not be lower than 0.5MΩ, and the leakage current per kilowatt should not exceed 0.5mA. Its power should also be checked to see if it meets the order requirements (deviation ±5%). After the test, check whether all parts of the electric heater are complete and intact.