Most work site fires related to welding operations are caused by _____.

Most work site fires related to welding operations are caused by _____.
 
  a. electrical heaters
  b. right angle grinders
  c. cutting torches
  d. preheating fires

 Q. 2

When calculating the required flow rate for a hydronic heating system, you must know the _____.
 
  a. temperature differential across the terminals
  b. pressure differential across the terminals
  c. specific gravity of water
  d. Btuh output of the boiler

 Q. 3

To prevent the system refrigerant from quickly dropping in temperature and pressure, refrigerant recovery should:
 
  A) Begin with liquid.
  B) Always take place while the system is operation.
  C) Only be attempted in the summer.
  D) Begin with vapor.