Requirements And Test Acceptance Methods For Aluminum Diecast Heater
Requirements and test acceptance methods for Aluminum Diecast Heater
(1) steam turbine Aluminum Diecast Heaters should meet the following requirements:
The raw material of Aluminum Diecast Heater shall meet the following requirements:
The components of magnesium oxide shall be in accordance with the provisions of hg3-1294-80 "magnesium oxide";
Magnesium oxide must be dried and used;
(3) aluminum die-casting electrothermal materials used in the heater of 0 cr27a17mo2 high resistance electric thermal bonding wire, its working temperature is 400 ° C, technical requirements according to GB1234 "high electric resistance alloy" regulation;
The protective casing material of Aluminum Diecast Heater is 1Cr18Ni9Ti stainless steel tube. Its technical requirement is according to YB804 stainless steel seamless steel tube. Use other materials to be agreed upon by the manufacturer and the user;
After removing the burr from inside the protective casing of the Aluminum Diecast Heater, clean it with gasoline or kerosene and blow dry to use it.
2. The finished product of Aluminum Diecast Heater shall meet the following requirements:
The rated working voltage of Aluminum Diecast Heater is 220 plus or minus 20V. Dc 100V, low pressure 50V;
(2) Aluminum Diecast Heater inserted within 1 m in length, its axis straightness is not greater than 0.3 mm Ø; Insertion length in 1 to 2 m, its axis straightness is not greater than 0.4 mm Ø;
The diameter deviation of the insertion part was -0.20mm / -0.50mm;
The length deviation of the insertion part is plus or minus 5mm, the deviation of the heating length is plus or minus 5mm, and the length of the cold end of the base is 25-30mm.
The Aluminum Diecast Heater is required to be hot and uniform when used, and it is not allowed to have local overheating.
(2) for the life test of Aluminum Diecast Heater, the heating time is 10-20min. In the case of intermittent heating, the total clearance between the hole of the bolted center and the Aluminum Diecast Heater was 0.8-1.3 mm, and the cumulative life span was not less than 50h.
(3) the connection between the alloy resistance wire and the lead wire shall be firm and reliable, and shall not be loose. The enclosure must be well grounded.
(4) after the steel casing of Aluminum Diecast Heater has been cooled and shrunk, the surface shall be inspected with a shading test or a magnifying glass of more than five times, which shall not have any defects such as cracks. The shrinkage should be unidirectional.
(5) the sealing of the cold end of aluminum casting heater shall be sealed tightly so as to avoid moisture entering and damaging insulation.
(6) Aluminum Diecast Heater manufacturing is completed, after a month and a half, with 500 v at room temperature to measure the insulation resistance by megger (available in the factory or the user) should be not less than 50 m Ω.
3. Test methods and acceptance rules
Each after assembled, Aluminum Diecast Heater at room temperature with 500 v megohmmeter Ω measuring the insulation resistance shall be not less than 50 m. It was subjected to 1500V pressure test and lasted 1min without breakdown or flash. Then in the air under the rated working voltage electrical heating 2-3 min, can not have overheating phenomenon, and the insulation resistance shall be not less than 0.5 M Ω, leakage current per kilowatt no greater than 0.5 mA. Check whether the power is in accordance with the order requirement (deviation plus or minus 5%). After the test, check whether the parts of Aluminum Diecast Heater are intact.