Page 145 - CITS - Welder - Trade Practical

WELDER - CITS

EXERCISE 32 : Silver brazing on copper tube to tube
(OAW-04)

Objectives

At the end of this exercise you shall be able to
• prepare a bell mouth by heating the tip of the pipe
• select nozzle, filler rod, flux and flame for brazing
• tack the bell mouth joint and braze the joint using pipe welding technique
• clean the joint and inspect for surface defects.

Job Sequence

1 Prepare a copper tube as per dimension.
2 Expand the copper pipe to form as a bell mouth.
3 Clean and remove the surface oxides by wire wool.

4 Select the nozzle No.5 and 1.6mme phosphorus bronze or 27-35% filler rod.
5 Apply flux to the filler rod.
6 Set the oxidising flame.
7 Insert the copper tube into the bell mouth of copper be and tack at 3 places

8 Keep the tack welded pipes with their axes vertical
9 Surt Brazing at the mid point of two tack welds and and the first fun after brazing half the circumference of the
pipe,

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CITS : C G & M - Welder - Exercise 32