Test Methods and Acceptance Rules
Insert part diameter deviation is -0.20mm/-0.50mm;
④ Insert part length deviation is ±5mm, heating length deviation is ±5mm, bottom cold end length is 25-30mm;
⑤ The electric heater requires uniform heating during use, and local overheating is not allowed.
(2) When conducting 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 is not less than 50h.
(3) The connection between the alloy resistance wire and the lead wire should 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 should be inspected by dye penetrant testing or with a magnifying glass of 5 times or more, and there should be no defects such as cracks. The tube should be formed in one direction during reduction.
(5) The cold end seal of the electric heater must 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 performed at the manufacturer or user site) and should not be less than 50M Ω.
Note: The above information and technical parameters are compiled and released by Yangzhou Dali Electric Co., Ltd.
