cm2112 MIDTERM T/F
Drop hammers are suitable for driving piles on remote projects that require many piles and for which the time of completion is an important factor. Select one: True False
F
Varying the amount of steel in the plastic pile core does not alter the piles' physical properties of toughness, resilience, and specific gravity. Select one: True False
F
A double-block-and-bleed system is considered a complete shutoff.
FALSE
A socket weld is made by joining the ends of two pipes together.
FALSE
Brass is stronger than steel.
FALSE
Bronze alloys contain 90% or more Aluminum.
FALSE
Butt welding is not often used in industrial construction.
FALSE
Corrosion is not a major issue for process plants
FALSE
In a butt weld, one pipe is inserted into a larger fitting and welded.
FALSE
Lead is a strong material at high temperature.
FALSE
Low carbon steel is not a very satisfactory material for most plant applications due to its high price.
FALSE
Nominal pipe sizes are usually the same as their actual inside or outside diameters
FALSE
Nonferrous Alloys contain large amounts of iron.
FALSE
Piping of the same size (e.g., all 4" pipe) has a constant inside diameter.
FALSE
Process equipment is designed exactly for normal operating pressure.
FALSE
Schedule 10 pipe is considered heavy wall pipe.
FALSE
Stainless steel is resistant to rusting but not corrosion.
FALSE
Steels that contain 10% or more of alloying metals are called low-alloy steels.
FALSE
The strength of metals increases as temperature increases.
FALSE
Trepanning is not used to inspect the welding on new storage tanks or similar equipment.
FALSE
XS pipe means "extra small" pipe.
FALSE
Concrete piles cure for 21 days or more to reach driving strengths. Select one: True False
T
"Brass" is a term used to describe a family of alloys of copper and zinc.
TRUE
A 3" schedule 40 pipe will have a different wall thickness than a 4" schedule 40 pipe.
TRUE
A paddle blind is inserted between two flanges, with a gasket on each side, while a figure-eight blind is designed to be installed inside the piping.
TRUE
A thread compound or Teflon tape is used on screwed joints for lubrication and to aid in sealing the joint.
TRUE
Aluminum and silicon bronzes are more resistant to salt water than brass.
TRUE
As operating temperature increases above 650°F, the strength of low-carbon steel decreases, becoming significant between 950°F to 1000°F.
TRUE
Besides affecting strength, temperature has a profound effect on corrosion rates.
TRUE
Blocking in equipment unprotected by relief valves can exceed design conditions and cause failure.
TRUE
Brass and Bronze are from the family of copper alloys.
TRUE
Brass loses significant strength when heated.
TRUE
Brasses are widely used because of their resistance to corrosion from water containing various impurities that are corrosive to steel.
TRUE
Bronzes are from the family of copper alloys.
TRUE
Cathodic protection systems can protect equipment indefinitely as long as sacrificial anodes are replaced and current flow is open
TRUE
Cathodic protection systems can protect equipment indefinitely as long as sacrificial anodes are replaced and current flow is open.
TRUE
Flammable liquid containers can build up static charges as the material is pumped in.
TRUE
Flanges are made in various thicknesses and for various bolt sizes according to the pressure and temperature of the service.
TRUE
In addition to specifying pipe by schedule, pipe is also sometimes specified as STD, XS, or XXS, along with pipe size.
TRUE
Measuring wall thickness through drilled holes, called trepanning, is the most accurate method when transfer calipers cannot be used.
TRUE
Most piping used in process units is carbon steel, because it is fairly economical and has a wide temperature range.
TRUE
Nickel Alloys are used for processes that involve acids and caustics.
TRUE
O.D. = I.D + 2*wall thickness
TRUE
Piping fitting ratings of 150lb., 300lb., and 600lb. are common in chemical plants.
TRUE
Piping of the same size (e.g., all 4" pipe) has a constant outside diameter.
TRUE
Piping with threaded joints is generally much less expensive and easier to install than piping with welded joints.
TRUE
Raised face flanges use a gasket that fits inside the bolts and ring joint flanges use only a metal ring for gasketing
TRUE
Screwed piping is used in sizes up to 2" for handling nonhazardous materials.
TRUE
Screwed piping joints are tapered to provide a tight fit.
TRUE
Small pipes are commonly joined by the use of tapered pipe threads.
TRUE
Socket-welded fittings are usually used in 2" size and smaller; butt-welding is used in all sizes, but particularly in 2" size and larger.
TRUE
Some low alloys (carbon-, moly-, and chrome alloys) are used in high temperature service such as furnace tubes.
TRUE
Stress corrosion cracking and a high coefficient of expansion are two conditions that case stainless steel to deteriorate.
TRUE
The chemical industry has two methods to prevent fire hazards from static electric sparks - bonding and grounding.
TRUE
The materials used in piping construction are chosen to withstand the temperature, pressure, and other properties of the fluids being conveyed
TRUE
The most common composition of stainless steel is referred to as 18-8, and has 18% chromium and 8% nickel
TRUE
The pipe wall thickness increases as the schedule number increases.
TRUE
The weakest part of screwed piping is usually the joints.
TRUE
To secure the strength and oxidation (rusting) resistance of low carbon steel at high temperatures, small amounts of alloying elements are added.
TRUE
Two methods of cathodic protection are using sacrificial anodes and using impressed current anodes.
TRUE
Underground water pipes can function as a grounding device.
TRUE
Visual inspection is the most usual method for inspection.
TRUE
When stainless steel is heated, it expands at a rate approximately 150% of that of steel, which becomes a problem when stainless steel is used in close contact with other metals.
TRUE
Concrete piles are more suitable than any other type of piles for constructing foundations that require piles driven to great depths.
f
Valves True or False: a rising stem gate has a collar that keeps the stem from moving up or down. you cannot look at this type of valve and tell if it is open or closed
false
Valves True or False: all safety valves reseat after lifting
false
Valves True or False: ball valves should be used for throttling service
false
Valves True or False: bronze gate valves and brass gate valves are used in high temperature, high pressure services
false
Valves True or False: diaphragm valves typically are used in low-pressure applications and require packing
false
Valves True or False: gate valves are sized to fit the outside diameter of a pipe and a lot of restriction occurs when it is in the open position
false
Valves True or False: gate valves are used only when flow rates are restricted
false
Valves True or False: like the gate and globe valves, a ball valve will lift the flow-control device out of the process stream
false
Valves True or False: low-temperature and low-pressure situations may require a combination of threading and welding for gate valve seats
false
Valves True or False: the ball check is as durable as a lift and a swing check
false
Valves True or False: the composition disc is not renewable
false
The use of a water jet to assist in driving piles into sand speeds the driving operation. Select one: True False
t
Valves True or False: a relief valve is designed to open at a predetermined pressure
true
Valves True or False: a control loop usually consists of a sensing device, a transmitter, a controller, a transducer and an automatic valve
true
Valves True or False: actuators come in 3 basic designs: pneumatically (air) operated, electrically operated, and hydraulically operated
true
Valves True or False: ball valves do not generally seal as well as globe valves in high pressure services
true
Valves True or False: butterfly valves are used for throttling. however, it should be noted that they have nonuniform flow characteristics
true
Valves True or False: gate valves are the most common valve used for isolation
true
Valves True or False: gate valves should not be used to throttle flow for extended period
true
Valves True or False: gate valves typically are operated in the "wide open" or "completely shut" position
true
Valves True or False: globe valves are designed to be installed in high-use areas
true
Valves True or False: globe valves are most commonly used for throttling services
true
Valves True or False: plug valves provide very little restriction to flow and can be opened 100% with a one-quarter turn of the valve handle
true
Valves True or False: pneumatically operated actuators are the most common type of actuators
true
Valves True or False: relief valves are designed to lift slowly, whereas safety valves tend to pop off
true
Valves True or False: stainless steel gate valves are used in corrosive, high and low temperature services
true
Valves True or False: system pressure helps position the gate in its seat. the higher the pressure, the more tightly the disk fits into the seat.
true
Valves True or False: temperature changes, closing a valve too quickly, and pipe expansion can cause a valve to warp
true
Valves True or False: the body is the largest part of the gate valve
true
Valves True or False: the most common type of automated valve is a globe valve
true
Valves True or False: the most common way to classify valves is by the valves flow-control element design (e.g. gate, ball)
true
Valves True or False: the primary purpose of a valve is to direct and control the flow of fluids by starting, stopping, and throttling (restricting) flow to make processing possible
true
Valves True or False: the relief valves will reseat as soon as the pressure drops below the relief pressure and the spring tension is adjustable
true
Valves True or False: the seats in a gate valves fall into 2 categories: replaceable and fixed
true
Valves True or False: valves that are used for isolation are classified as block valves
true
Valves True or False: when compared to gate valves, globe valves have a much greater pressure drop across the valve
true
