brazing

What is the first step when brazing copper tubing?

• Purge the air from the system

• Remove any Schrader cores

• Cut the copper tubing

• Clean the copper with an emery cloth

What tool is used to deburr copper tubing after cutting?

• Needle nose pliers

• A navac deburring tool

• A wrench

• A torch

What is the purpose of flowing nitrogen while brazing?

• To cool down the tubing

• To clean the tubing

• To increase the heat

• To prevent oxidation inside the tubing

What is the correct setting for oxygen and acetylene when using a standard tip?

• 5 for both oxygen and acetylene

• 7 for acetylene and 11 for oxygen

• 7 for both oxygen and acetylene

• 10 for both oxygen and acetylene

What is the correct procedure to light the torch?

• Oxygen first, then acetylene

• Acetylene only, then mix in oxygen

• Oxygen and acetylene together

• Acetylene first, then oxygen

What type of flame is typically sought for brazing?

• Oxidizing flame

• Neutral flame

• Carburizing flame

• Reducing flame

What is the main reason for using wet rag heat blocking putty?

• To clean the tubing

• To apply flux

• To protect critical system components from heat

• To cool down the tubing quickly

Tags

NGSS.MS-PS3-3

What should not be used on steel when brazing?

• Aluminum repair rod

• Phosphorus bearing rods

• Separate paste flux

• High silver flux coated rod

Tags

NGSS.HS-PS1-5

What is the correct method to repair aluminum?

• Use phosphorus bearing rods

• Apply direct heat to the rod

• Heat until the flux goes clear and quiet, then apply the rod

• Use the same alloys and flux as for copper

What is the maximum test pressure for a system based on?

• The lowest maximum test pressure of the evaporator or condenser

• The pressure of the nitrogen tank

• The highest maximum test pressure of the evaporator or condenser

• The pressure setting on the regulator