Dip a bimetallic thermometer maintenance requirements and methods

Low pressure in the bimetallic thermometer attachment now use more varieties of products first hot shorten annex, prefabricated type accessories, cold type. They respectively have the following characteristics: the & # 8203; A, heat shorten the attachment data is commonly used in polyethylene, ethylene - Vinyl acetate ( EVA) And ethylene propylene rubber and other materials composition of blend composition. Such products, first choose tube processing electrical stress have problem. Which to choose parameters control act to relieve the electric field stress have gathered. Primary strengths is lightweight, easy installation, function is good. The price is cheap. Stress of the pipe is a moderate volume resistivity ( 1010 - 1012Ωocm) In large, dielectric constant ( 20 - - 25) Special electrical parameters of heat shorten the tube, using electric parameters persecuted bimetallic thermometer insulation shielding of the stress of the fracture of evacuation into more evenly spread along the stress pipe. This skill can only be used for 35 kv and below bimetallic thermometer in the attachment. Because the voltage grade heating and high stress pipe will not secure operation. Key skills in the use of the problem is: to ensure that electrical parameters of stress pipe e. can secure work must reach the standard. Silicon grease effect: silicon grease filling bimetallic thermometer insulation semi-conducting layer fracture of the air gap to eliminate gas, to reduce the intention of partial discharge. Stress pipe and insulation shielding lap interval: crosslinking bimetallic thermometer due to internal stress when handling bad will attack larger shorten in the operation, thus the stress pipe and insulation shielding device accessories not less than 20 mm, its shortened stress pipe and insulation shielding from in case. Heat shorten attachment for elasticity is small, heat bilges cold shrink during operation may make the interface produces the air gap, sealing ability is important, therefore, in order to avoid moisture in. Second, the prefabricated type information for silicone rubber and ethylene propylene rubber commonly used accessories. First choice in how much structure stress cone to deal with the stress have problem. Its primary advantage is good information function, the device is more concise and easy, without heating device, has good elasticity, make the interface function improved greatly. Is in recent years, low pressure and high pressure in the primary form of bimetallic thermometer is chosen. The deficiencies in insulation outside diameter of bimetallic thermometer scale demand is high, usually the amount of interference in 2 - 5mm( The bimetallic thermometer insulation outside diameter should be greater than the inner hole diameter of bimetallic thermometer in attachment 2 5毫米) , interference quantity is too small, bimetallic thermometer attachments will present problems; Interference amount is too large, bimetallic thermometer attachment device is difficult. Especially on the center joint issues outstanding, the device is inconvenient, and often become a problem. Moreover the price is more expensive. Key skills in the use of the problem is: the scale of the attachment with the scale of the bimetallic thermometer for device cooperate to meet the prescribed requirements. In addition also need to choose silicon grease lubrication interface, so that the device together fill the air gap of the interface. Prefabricated attachment general rubber elasticity can surely sealing effect by itself, sometimes can choose sealants and elastic fixture enhancing seal.