• English
  • 中文
News detailCurrent Location:Home > News > News detail

Preheating before construction of heat shrinkable sleeve

Time:2020/5/13 posted:Kehong Enterprises Co.,Ltd.

Before using the heat shrink sleeve, it is necessary to preheat the steel pipe. The general preheating temperature is 70-90 degrees Celsius.

The pre-heating of the patch can be flame heating or electric induction heater. Flame requirements for different pipe diameters: the diameter of the pipe is less than or equal to 450mm, medium-strength flame or electric induction heater is used, and the minimum torch specification is 150000Btu / hr (1Btu = 1.055kj). The pipe diameter is greater than or equal to 450mm, using medium to strong flame heaters or electric induction heaters, and the minimum torch specification is 300000Btu / hr. When the pipe diameter is greater than or equal to 760mm, an electric induction heater or infrared heating device is used. Of course, many on-site construction is not so good, generally we recommend the liquefied gas baking gun for preheating.

      There are two main purposes for preheating. One is to remove the humidity on the surface of the steel pipe, because if there is moisture, if it is not removed, after the epoxy primer is applied, the moisture will form a layer of the membrane, which may cause the primer to come off. The second is that there will be a certain temperature on the surface of the steel pipe after preheating. This temperature will cause the epoxy primer to react chemically and slowly cure before the heat shrink tape and heat shrink sleeve can be installed.

      Before sandblasting and derusting the surface, we should preheat the steel pipe of the repaired part to a temperature of at least 30 degrees Celsius or 40-50 degrees Celsius above the dew point, which can be adjusted appropriately according to the ambient temperature. Celsius, the preheating temperature at the mouth should be increased to more than 70 degrees Celsius.






Pre:Heat-shrinkable sleeve peel strength test
Next:Expansion speed of the heat shrinkable sleeve
Copyright © 2013-2020 Kehong Enterprises Co.,Ltd. All rights reserved