Modules I, J & K Highlights Flashcards
Many valves have two ratings: the steam rating and the water, oil and gas (WOG) ratings which is also called ________________________
cold working pressure (CWP) rating
What does the marking 125S on a valve indicate?
Steam rating. They can be displayed with the pressure number followed by the letter S
What does the marking 150WSP on a valve indicate?
Steam ratings. They can be displayed with the pressure number followed by the letters WSP- working steam pressure
Plug valves ________________ of liquids.
Regulate the flow
Which valve has an almost straight line of flow and offers little resistance
Swing check valve
Which valve changes direction twice as it passes through the valve?
Lift check valve
Which valves start to open at a pre-set pressure?
Relief valves open at a pre-set pressure (cracking pressure)
Full flow pressure for the valve may be ________ higher for the valve to be wide open
20%
____________________ are devices that measure process variables and provide a signal to a control system for decisions making (logic)
Transducers
A ________________________ is a type of multi-phase electric motor that does not usually rotate continuously
Stepping motor
When doing a visual inspection of a seat ring, what should you look for?
corrosions, erosion, or wire drawing (deep grooves on a valve seat or flange caused by the scouring action of escaping fluids)
How is tubing sized?
by its actual outside diameter NOT the nominal inside diameter as used for pipes
What materials is tube available in?
steel, copper, aluminum and plastic
The two standard flare angles for fittings are 37˚ and 45˚. What is 37˚ used for?
37˚ is intended for high-pressure service and meets industrial hydraulic standards
The two standard flare angles for fittings are 37˚ and 45˚. What is 45˚ used for?
45˚is used on low-pressure automotive or refrigeration application
When tightening a flared joint, you first tighten finger-tight, then you use a flare tubing wrench. How much should you turn the nut for tube sizes up to 5/8”?
turn the nut 1/4 turn for up to 5/8 inch
When tightening a flared joint, you first tighten finger-tight, then you use a flare tubing wrench. How much should you turn the nut for tube sizes over 5/8”?
turn the nut 1/8 turn for over 5/8 inch
How do you install a flareless fitting?
Tighten the nut 1/6 to 1/3 of a turn after finger tightening
How do you tighten welded fittings?
Heat the welded area to a dull red and then allow it to cool in the air
What would you use when you have to connect a fluid conductor to moving parts?
A hose
Some major hose manufacturers establish the working pressure at ____________ of the bursting pressure
One quarter
The pressure rating for hoses made to North American standards is given in __________ and hoses made to __________
psi, isometric (ISO)
The pressure rating for hoses made outside of North America are rated in ____________
Megapascals
A megapascal is equal to about _______ psi
145
Hydraulic hose fittings are produced with male fittings with a 37˚ JIC seat angle. What does JIC stand for?
Joint industry conference
What is a disadvantage of a pancake blind when compared to a spectacle blind?
the flanges have to be spread in order to remove the blinds. With spectacle blinds, the piping system is designed to accommodate the blind.
How do you purge?
You introduce an inert gas such as nitrogen or carbon dioxide into the piping system, vessel or compressor and then purge it with air.
Which mediums are used to purge?
The medium chosen must suit the application and equipment. Some common mediums are nitrogen, carbon dioxide, steam, water and air.
How is the location of a permanent gas detector chosen?
Based upon the characteristics of the gas. If the gas is heavier than air, the sensor mounts below the equipment, if the gas is lighter than air, the sensor mounts above the equipment.
What is one factor that affects the sealing ability of a flat gasket?
The thickness of the gasket
Gasket thickness is critical. By changing gasket thickness, you may change ________________________
the internal alignment and clearances
Give an example of a common type of rubber/other elastomer
nitrile (Buna-N)
Whenever a piece of equipment is disassembled for maintenance, a new ______ should be installed.
gasket
What are pipes?
Rigid connectors with thick walls that can be threaded or welded
What is the benefit of using cast iron pipe?
corrosion resistance
Galvanized coatings should not be used in ________________
hydraulic service
In pipe sizing, the _______________ diameter is kept constant
outside
For heavier weights, a 1-inch pipe would have a ______________ inside diameter
much smaller
Inside diamter is used for sizes up to and including _____________
12 inches
Outside diameter is used for pipe sizes _______________
over 12 inches
Groove and clamp joints are normally used on pipes that are ______________ in diamter
at least 3 inches
Groove and clamp joints are commonly called
Victaulic couplings or gruvlok
