600-650 Flashcards
(36 cards)
- If the boiler water pH has been allowed to go below 7.0 for more than one hour there is a high potential for _________________.
a. caustic embrittlement
b. caustic gouging
c. scale build up under which the corrosion will be enhanced
d. hydrogen damage or hydrogen embrittlement
d. hydrogen damage or hydrogen embrittlement
- Chemical treatments to prevent corrosion usually work by _______________________.
a. forming a protective film on the metal surfaces
b. absorbing the corrosive elements into itself (the chemical) to form a passive solution
c. combining with the corrosive elements to form a non-corrosive product that can then be precipitated out of the process fluid
d. neutralizing the electrolyte so it will not conduct an electric current
a. forming a protective film on the metal surfaces
- As the pH of the environment decreases, the corrosion rates _____________.
a. decrease
b. remain the same
c. increase
d. decrease or increase depending upon the fluid flow rates
c. increase
- If the anodic area is relatively small compared to the cathodic area, the corrosion will be in the form of __________.
a. generalized surface area corrosion
b. under deposit corrosion
c. very sporadic corrosion that moves around the entire surface of the metal
d. deep pits
d. deep pits
- A substance that retards corrosion when added in specific concentrations to an environment is called a/an__________________.
a. passifier
b. neutralizer
c. corrosion enhancer
d. corrosion inhibitor
d. corrosion inhibitor
- The first layer of an absorbed film type of corrosion inhibitor is _____________________________________________.
a. strongly bonded to the metal surface
b. weakly bonded to the metal surface
c. coating the metal surface due to its low viscosity and inability to flow
d. the sacrificial layer that continues to wash away and must be replaced on a continuous basis
a. strongly bonded to the metal surface
- Neutralizing amines are volatile materials added to a system to __________________________.
a. neutralize the acidity and increase the pH of the fluid
b. neutralize the caustic action of the fluid and eliminate caustic gouging
c. neutralize the corrosive action on the surface of the metal and build a passifying film
d. neutralize the corrosive action of the oxygen in the water by absorbing the excess O2
a. neutralize the acidity and increase the pH of the fluid
- Not adding enough passivating inhibitor to keep the entire metal surface covered can cause ___________________.
a. the coated areas to be kept corrosion free but the other areas will still be susceptible to minor corrosion
b. enhanced pitting in the uncoated anodic areas of the metal
c. the entire surface area to be protected as it interrupts the flow of electric current through the metal
d. the entire metal surface to corrode faster
b. enhanced pitting in the uncoated anodic areas of the metal
- The principle of cathodic protection is to change the whole surface of the metal into a cathode so that _________________________.
a. the flow of electrons from the metal surface is equal across the entire surface which reduces pitting and other corrosive actions
b. the electrolyte will not be able to support the flow of electrons
c. the anode will move to a less critical part of the equipment
d. there is no net flow of current from any point of the metal surface to the electrolyte
d. there is no net flow of current from any point of the metal surface to the electrolyte
- Sacrificial Anodes are used to reduce galvanic corrosion of tanks and/or vessels by ____________________________.
a. accepting the corrosion action in place of, or instead of, the main equipment surface
b. isolating the electrolyte from the internal surface of the main equipment
c. reversing the flow of electrical current from the cathode to the anode
d. stopping the flow of electrical current completely by breaking the circuit
a. accepting the corrosion action in place of, or instead of, the main equipment surface
- When several anodes are buried close together and electrically connected to function as a single unit they are called:
a. Buried cathodic protection
b. Underground cathodic protection
c. A groundbed
d. An underground bed
d. An underground bed
- Cathodic protection always uses ___________________.
a. alternating current at 110 volts and 60 hz
b. alternating current at 220 volts and 60 hz
c. alternating current at 110 volts and milliamp current flow
d. direct current of varying rates
d. direct current of varying rates
- Corrosion coupons are:
a. Pieces of metal inserted into a system to sacrificially corrode instead of the metal surface that is being protected.
b. Pieces of metal inserted in a system to evaluate the corrosiveness of the system.
c. Pieces of metal inserted into a system that will direct the flow of electrons from the cathode to a neutral point and reduce the corrosion.
d. Pieces of metal inserted into a system that will direct the flow of electrons from the anode to a neutral point and reduce the corrosion.
b. Pieces of metal inserted in a system to evaluate the corrosiveness of the system.
- One of the most serious corrosion problems in the Oil and Gas and Pulp and Paper industries today is Biological Corrosion.
a. True
b. False
a. True
- Stress corrosion cracking happens quite quickly in steels and certain copper containing materials.
a. True
b. False
a. True
- Monitoring and controlling the boiler water treatment chemistry has no real impact on the potential for caustic corrosion as it is mainly caused by poor boiler circulation.
a. True
b. False
b. False
- Both too high and too low a fluid flow velocity can increase the rate of corrosion.
a. True
b. False
a. True
- Passivating inhibitors actually cause the metal to corrode which creates a protective oxide film on the metal surface that protects the metal from further corrosive action.
a. True
b. False
a. True
- When correctly installed, cathodic protection will completely stop the corrosion process.
a. True
b. False
b. False
- The positive terminal of the power supply must always be connected to the structure which is to be protected and the negative terminal must be connected to the ground bed or severe corrosion of the structure will result.
a. True
b. False
b. False
- What information does the Material Balance Table provide?
a. Material specifications that the piping and vessels are constructed of.
b. Heat balance across the plant.
c. Volume of process products that will be produced across the plant.
d. Pressure, temperature, composition and flow rates of the various process streams shown.
d. Pressure, temperature, composition and flow rates of the various process streams shown.
- A mechanical flow diagram is commonly known as a P&ID which is an acronym for the words?
a. Power and Instrument Drawing
b. Process and Instrumentation Diagram
c. Piping and Instrumentation Drawing
d. Piping and Insulation Diagram
b. Process and Instrumentation Diagram
- What does the P&ID show?
a. Less detail than the PFD.
b. More detail than the PFD.
c. The same amount of information as the PFD but in a more logical format.
d. Completely different information than the PFD shows.
b. More detail than the PFD.
- What do the Operations and Engineering staff use the Mechanical Drawings for after completion of construction?
a. Reference material for designing other similar facilities.
b. Reference material for writing ladder logic for the instrumentation and controllers.
c. Reference and training materials on the details of the processes and control systems.
d. They will actually just be filed and not really used again as they serve no purpose once the facility is built and operating.
c. Reference and training materials on the details of the processes and control systems.
