This topic contains a solution. Click here to go to the answer

Author Question: The oil in a vacuum pump should be changed _____. a. about every five minutes of pump operation ... (Read 135 times)

SGallaher96

  • Hero Member
  • *****
  • Posts: 509
The oil in a vacuum pump should be changed _____.
 
  a. about every five minutes of pump operation
  b. only when changing from one refrigerant to another
  c. immediately after pumping down a wet or contaminated system
  d. about every 25 hours of pump operation

Question 2

It is important to clean dross and carbon deposits from a cut surface before welding because they can _____.
 
  a. produce extremely hazardous fumes during welding
  b. form hard, brittle zones and porosity in the weld zone
  c. damage certain welding equipment components
  d. cause molten metal to be blown considerable distances



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Zebsrer

  • Sr. Member
  • ****
  • Posts: 284
Answer to Question 1

c

Answer to Question 2

b




Zebsrer

  • Sr. Member
  • ****
  • Posts: 284

 

Did you know?

Addicts to opiates often avoid treatment because they are afraid of withdrawal. Though unpleasant, with proper management, withdrawal is rarely fatal and passes relatively quickly.

Did you know?

Nitroglycerin is used to alleviate various heart-related conditions, and it is also the chief component of dynamite (but mixed in a solid clay base to stabilize it).

Did you know?

A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.

Did you know?

During pregnancy, a woman is more likely to experience bleeding gums and nosebleeds caused by hormonal changes that increase blood flow to the mouth and nose.

Did you know?

In 2010, opiate painkllers, such as morphine, OxyContin®, and Vicodin®, were tied to almost 60% of drug overdose deaths.

For a complete list of videos, visit our video library