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What is the typical ID of PE pressure-rated pipe?
equivalent of sched 40 IPS
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Why are plastic piping and plastic lined piping desirable?
sludge/wax buildup less than on iron pipe
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What is the most commonly used plastic piping?
PVC
Polyvinyl Chloride
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How is PVC piping joined?
solvent welding (bell and spigot type joint), threaded joints (at least sch 80), victaulic, or fusion.
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How is PE (Polyethylene) joined?
fusion, compression fittings, insert fittings, CANNOT be solvent welded.
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What plastic is usually used in chemcially corrosive situations?
What colour is it?
PVDF.
Red when used as pipe.
Black as liner
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What are the colours for PE piping?
orange, yellow, or black
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What is PVDF piping good for?
- good until 280'F.
- excellent chemical resistance
- good weathering and good strength
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Describe PTFE
Teflon. White. A Fluorocarbon that is virtually inert to all chemecials exepect fluorine and molten alkali metals like sodium an potassium.
The lowest coefficient of friction of almost any solid material. Only choice for applications above 300'F
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What two weld procedures can be used on cement and mortar lined piping?
lap and butt
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How are most lined pipes joined?
mechanical fittings and synthetic gaskets.
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In what condition would one use pipe and fittings with higher pressure ratings than needed by operating pressure or temps?
If water hammer were a concern
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What is PVC type III used for?
conduit and drain piping
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what can happen if cooling of the pipe below the installation temp results in excessive tensile forces?
pullout especially of compression joints.
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What is the max compression allowed on the gasket faces between two rubber lined flanges?
gasket faces should ot be compressed more than one thrid of the initial thickness
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What should be isntalled between the faces when joining the flange of a lined pipe to the flange of an unlined pipe?
gaskets and flat full-face spacer ring
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What are the five families of thermoset resins?
- - polyester
- - vinyl ester
- - epoxy
- - furan
- - phenolic
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What is the first layer of FRP piping usually called?
veil layer
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What are the two methods of filament winding?
What is so good about filament wound pipe?
- - biaxial winding
- - helical winding
- strongest FRP pipe made
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What is a catalyst? (FRP)
a hardener mixed with the resin to trigger the chemical rxn that cures the resin
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What are promoters? (FRP)
help trigger the rxn.
NEVER add directly to the catalyst ---> BOOM!
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What is a thixatropic agent? (FRP)
added to resin to increase high static shear strength (viscosity) and low dynamic shear strength
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What is the operating temperature of FRP pipe?
-40'F to 300'F
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When preparing an FRP Butt and Wrap joint how far should the veil extend over each end of the pipe
- 2 inches on each side
- 2 inches overwrap
- width increases 1/2" layer
- length increases 1/4" layer
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(FRP) What will happen if the scoured finish on aramid fibres is not protected from contamination caused by mineral deposits from water/oil on your skin?
resins will not adhere to the glass fibres
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(FRP) What is the name for the strands formed by spinning glass fibers together?
rovings
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(FRP) What material is used in areas where relatively sharp radii have to be reinforced?
cloth
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(FRP) How much force is required to properly torque a lock collar?
fingertight
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(FRP) How much twist or turn is allowed to align the fitting marks when pushing an adhesive type joint together?
no more than 3/8" rotation
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What is corrosion?
The wasting away of material due to the combination of new elements contained within various atmos. or service environments
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how do biological organisms affect corrosion?
absorbing H from surface of steel, H acts as resistance to corrosion
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What is oxidation?
the coating of oxides on material surfaces. Ocurs when O combines with material
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What makes Stainless Steel corrosion resistant?
Chromium oxide
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Define bending strenght
quality that resists forces from causing a member to bend or deflectin the direction the load is applied
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define brittleness
- - metal fracture
- - low stress
- - complete lack of ductility
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define ductility
- ability of metal to stretch, bend, twist w/o breaking or cracking
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define elasticity
- ability of material to return to original shape
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define hardness
- materials ability to resist indentaiton or penetration
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define impact strength
ability of material to resist loads applied suddenly and often at high velocty
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define tensile strength
ability of material to resist forces acting to pull or push the material apart
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Define ferrous metals.
an appreciable or large enough iron content to affect the properties of a metal
Alloy steels are considered ferrous as they have more than 50% iron
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What code recognizes a wide variety of non-metalllic piping materials to be used on corrosive or special applications?
B31.1 and B31.3
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Some B31.1 and B31.3 points of consideration of possible:
- - destruction by fire
- - decrease tensile strength
- - effects of toxicity
- - adequate support for flexible pipe
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What is the carbon content in an alloy steel?
0.5 to under 2%
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What is an alloy steel?
- -ferrous metal
- - mix of one or more elements added to carbon steel not chemically bonded
- - greater toughness, strenght, resistance to wear/corrosion
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What does copper do when added to an alloy steel?
- increase corrosion resistance
- reduce temp resistance
- improves machinability
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what does molybdenum do when added to an alloy steel?
greatest hardening effect of any element except carbon.
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What does nickel do when added to an alloy steel?
- -increases ductility while keeping strength
- - when 25%-35% added beomes tough with high resistance to corrosion and shock
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What does tungsten do when added to an alloy steel?
makes steel tough
usually used for tools
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Define low allow steel.
1.5% to 5% total alloy content
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Define high alloy steel.
alloy levels in excess of 10%
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Properties of 300 series SS.
- - expands 50-60% mroe than carbon steel
- - used most commonly in pipe industry (304SS most, 316SS for extraordinary apps)
- - Chromium content may be > 10.5%
- - is magnetic
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What are the three major SS groups?
- - austentic
- - ferritic
- - martensitic
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What are the most commonly used metals for non-ferrous alloys?
- - Al
- - Copper
- - Nikel
- - titanium
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Whta are the problems with Al pipe?
- - low heat resistance
- - cannot be used where erosion of oxide layer likely
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What is brass?
Copper and zinc (up to 40%)
zinc decreaes weldability as zinc content increases
toxic vapours when welding
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what is bronze?
copper and tin (up to 10%)
tin increases hot crack potential when welding
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Nickel alloys.
- - monel (67% nickel, 30% copper)
- - inconel ( 80% nickel, 15% chromium, 5% iron)
- - high strength
- - very corrosion resistant to acids and high heat
- - Inconel used at 1830-2200'F
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What is Ti pipe used for/
- - highest corrosion resistance
- - less heat resistant than nickel alloys
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How is carbon steel piping designated by ASME?
By UNS?
- - SA followed by 2 or three digit number grade
- - K or S followed by 5 numbers
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Can you stress releive SS?
nope
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Can an Oxy-acet or tiger torch be used on pre or post-heat on critical apps?
no
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What is pickling?
thin layer of corrosion put on SS
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Do most alloys need stress releivng?
yes, just not SS
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Which metal can be used in chemcial processes requiring alternate contact with strong acids and alkalis?
zirconium
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Compressive strength is teh ability of material to?
resist being crushed
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What is the most used welding process on titanium?
GTAW
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What is the best corrosion resistant stainless steel?
austentic
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What is the most commonly used thermoplastic piping?
PVC
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Which type of liner is the most used and least expensive?
PP
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How many expansion loops are required between any two anchor points on FRP pipe?
1
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What may be used as guids on FRP piping?
u bolts
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What kind of copper tubing can be used for steam tracing?
K and L
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