Regulations & Safety第 71 / 240 题
A technician plans to braze on a system. What is the correct sequence regarding the refrigerant charge before applying heat?
a.Recover the refrigerant and relieve pressure before brazing, and ensure no refrigerant remains where the flame will be
b.Vent the refrigerant quickly, then braze
c.Leave the charge in place; the heat will help it flow
d.Braze first, then recover whatever is left
解析
Before brazing, the technician must recover the refrigerant and relieve system pressure so that no refrigerant remains where the flame will be applied, preventing toxic decomposition and dangerous pressure. Brazing first, leaving the charge in, or venting the refrigerant are all unsafe or illegal. Purging with dry nitrogen while brazing is also good practice to prevent oxidation inside the tubing.
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