-
who provides specs defining jurisdictional boundaries when more than one code provides criteria for a system or components?
The owner
-
Canadian welding standards are set by:
CWB
-
The rules for qualification of welding procedures is contained in...
ASME Section IX
-
Which code requires third party inspection?
ASME
-
Within CSA Standards where do you find info on boilers and pressure vessels?
Mehancial/Industiral section
B51
-
What code and section is on care and use of heating boilers?
ASME Section VI
-
ANSI/ASME B31.1
Power systems
-
ANSI/ASME B31.3
Process piping
-
ANSI/ASME B31.5
Refrigeration
-
ANSI/ASME B31.9
building piping
-
When does an appicable code for mech. equip become effective?
when equip purhcase order awarded
-
Who issues standards for pipe restraints?
MSS
-
Which code and section contains info for acceptable materials?
ASME Section II
-
What is on the ASME boiler stamp?
H
-
What does ANSI provide to fabricators?
recommended procedures that have been demonstrated to be code compliant
-
Cast iron boilers are limited to...
30 psi
-
LTHW boilers are usually rated in
net rated in BTUH or kW/hr
-
HTHW boilers are usualy rated in:
gross rated in MBH or BHP
-
HTHW boilers are covered under ASME section
I
-
1 BHP =
- = evaporation of 34.5 lbs of water in 1 hour
- = approx. 33,500 BTUs
-
1 hot water EDR = ____ BTUH
150 @ 160'F
-
1 steam EDR = _____ BTUH
240 @ 1psi & 215'F
-
What is input
amount of fuel burned by the burner
-
Gross output=
total heat output of boiler available as steam or water. The portion of the input that is left after some original heat is ost in stack or insulating jackets
-
A min of ____ psi must be maintained to avoid water flashing into steam
4psi
-
The safety relief valve must have the ____ size inlet and outlet
same size
Outlet can be make bigger, but not vice versa
-
Low pressure boiler limits...
- - all steam operate not in excess of 103kPa (15psig)
- - all hot water operate not exceed 1100kPa (160psig) and 250'F
-
High temp boilers intended for operation abbove....
160 psig and 250'F
-
how are cast iron and copper heating boilers usually rated?
Net
-
What is an advantage steam boilers have over water?
no pump needed.
-
steam can travel at _____ km/hr in pipes. Low temp water circulates best at _________
100km/hr
2-4ft/sec residential, 7-9 commercial
-
What is the least efficient boiler design?
firebox
-
Define Load Tracking Ability.
ability of boiler to respond to changes in steam or hot water demand
-
Boiler feedwater supply line sizes?
- 1/2" up to 100sqft of heating surface
- 1" over 100sqft heating surface
-
Describe Hartford loop.
- - designed to prevent complete drainage of boiler.
- - connects to bleeder line 2-4" below NOWL
- - connected with short nipple to stop vapour accumulation
- - vertial riser same size as bleeder line to ensure low velocity
- - bottom can be rodded out.
-
Where does the blow-off line go?
lowest part of the water space on a boiler to clean out sludge
-
Blow-off valve specs
- - also called master valve
- - must hve 5 wheel turns
- - used to lower theboiler water level.
-
Blow-off valve specs;
- - min 1/2" with less than 100sqft heating space
- - min 1" more than 100 sqft
- - max of 2.5", use second if more required.
-
What is the slope on a boiler steam header?
1/4" per foot
-
How is a header sized?
Cross sectional area must be greater than that of all cross-sectional areas of all nozzles attached.
-
Steam main grade =
1" of fall for each 20' of horizontal run
-
air gap
unobstructed vertical distance through free atmosphere between lowest opening from any pipe. Protects potable water.
Must be at least double diameter of supply pipe measured vertically above top of rim vessel. No less than 1"
-
anti-siphon breaker.
device installed on system to prevent vaccum from forming and water siphoning into potable water
-
RPBP
reduced pressure principle backflow prevention device
-
define pigtail
- - loop formed at 270' to 360' to create condensate trap in the line from teh steam space.
- - Prevents steam from contacting and damaging sensors.
- - Must be installed 90' to the face of an pressure controls (so they don't sway)
-
What does ASME say about blowdown valves?
must be quick opening and closing
-
ASTM definition?
American Society for Testing and Materials
-
PFI definition?
Pipe Fabrication Institute
-
Documents prepared by a professional group indiciating good engineering practices that are optional?
recommended practices.
-
Documents prepared by a professional group having requirements beleived to be good and proper engineering practice and that are written with mandatory requirements?
standards
-
When changes are made to codes, it is brought to ______ attention and any changes are ______
the owners, documented
-
Which section of ASME Secion IV applies to steam heating, hot water heating and hot water supply boilers and accessories?
HG
-
What section of ASME Section IV provides requirements for boilers constructed of wrought materials?
HF
-
What section of ASME Section IV provides requirements for boilers constructed of cast iron?
HC
-
AISC?
American Institute of Steel Construction
-
What MSS standard applies to pipe hangers?
SP-69
-
When was section 1 of the ASME code first issued?
1914
-
Section IX of ASME Code covers?
Welding and Brazing Procedures
-
What does PP mean under the Alberta pressure piping registration system format?
Pressure Plan
-
What are the two BASIC boiler classifications?
Portable and Stationary
-
What does Section 1 of the ASME code cover?
boiler construction in excess of 15psig or121'C
-
What does the IBR do?
sets standards for heating boilers,
-
Name two firebox boilers.
Horizontal return tube and Locomotive
-
Steel boilers are size rated based on standards set by:
SBI
-
What type of boiler has its furnace area loated within its shell and surrounded by water?
internally fired
-
What type of boiler are:
electric
firebox
HRT
Locomotive
Scotch Marine
Vertical tube
fire tube boiler
-
What type of boiler are:
Horizontal straight tube
"A" bent tube
"D" bent tube
Inclined bent tube
"O" bent tube
water tube boilers
-
How are cast iron and copper finned heating boilers for small applications usually rated?
net rated
-
high efficiency is considered:
over 90%
75% is rule of thumb if unknown efficiency
-
How many passes does the combustion gas have in a locomotive boiler?
1
-
How high may "O" type boilers operate?
1500psig
-
What type of boiler is better suited to handle wide variations of loads?
water tube
-
During short periods of time which style of boier is able to respond best to sudden demands for large volumes of steam?
fire tube
-
-
Horizontal Return Tubular (HRT)
-
-
What type of boiler could be used either to generate low pressure steam or produce low temperature hot water?
conventional cast iron
-
What type of boiler can be used to generate low pressure steam or low temperature water?
Conventional cast iron
-
ASME states that all hot water boilers shall NOT operate at pressures exceeding...
100psig.
-
What advantage does a steam system have over a hot water system?
Speed of transmission
-
Properly sized steam mains carry steam at about...
100km/hr or 60miles/hr
-
For residential hot water heating systems what is the max velocity?
4ft/sec
-
Which type of boiler is designed as a dual purpose boiler (steam or hot water)?
Conventional cast iron
-
What steel package boiler of the fire tube design is the most popular.
Scotch Marine
-
Define Load Tracking.
What is a boiler that has good Load Tracking?
the ability of a boiler to respond to load demand changes
Firetube boilers have good load tracking abilities.
-
What type of boiler is often chosen for applications where there are load swings for long periods of time?
Watertube boilers
-
What kind of boiler uses a heat exchanger to remove latent heat from its hot flue gases and as such needs drainage piping?
condensing boiler
-
What is the CSA B149.1 requirement for front clearance of a boiler?
24"
-
Heavy concentrations of dissolved or suspended particles in the boiler water may result in...
foaming
-
What are the gases naturally found in boiler make-up water called that are freed from the water as the boiler water is heated up?
non-condensable gases
-
What should be done to every threaded joint on the fuel firing train?
soap tested
-
Low pressure steam boilers are rated in? (2)
-
1 EDR =
240 BTUH @ 1psi @ 215'F
-
240 BTUH @ 1psi @ 215'F=
1 EDR
-
A "wet nipple" boiler refers to the fact that water can flow______
through the upper and lower port openings
-
A radiator air vent _____ when the steam contacts its heat actuated float valve.
closes
-
Steam _____ its heat energy as it changes to condensate
releases
-
What are the specs on a one-pipe counterflow system?
- grade = 1"/10'
- pipe needs to be 1 size larger than normally used.
-
What are teh specs on a one-pipe parallel flow system?
1/2" / 10' on the main
-
What is the required drain size for a boiler heatig 100sq/ft or less? over?
-
Where must the Manual Air Vents be located on a radiator?
top 1/3 so that air can come out, not steam.
-
What is the required grade on steam radiators?
1/2" / foot
-
What are the main factors to consider when sizing the pipe needed for a low-pressure steam system?
- 1. total pressure drop between the boiler nozzle outlet and the end of the condensate return system
- 2. the quantity of steam required, at a velocity that will not create excessive noise
- 3. the total equivalent length of the pipe and fittings between the boiler and farthest heating unit
** initial pressure at boiler should be high enough to overcome and pressure drop in the system. Usually about double the calculated pressure drop expected across the system
-
Let's talk about condensate removal...
proper drainage must be ensured ahead of any control valves, isolation valves, or pressure regulating stations. All low points and natural drainage points must be provided with drip legs.
* counterflow LPS heating mains should be dripped at a max of 150ft intervals.
-
When installing an ecentric reducer on a steam system how must it be situated?
flat side down, to prevent condensate buildup.
-
What should the grade of springpieces be?
1/2"/10ft
-
What size should drip legs be?
Same size as main.
If main is 6" or larger, drip leg can be half the size (no less than 4" though)
-
one pipe gravity return system
-
How is a two-pipe gravity return system balanced so the steam will fill each radiator at approx. the same time?
by proper sizing of the orifice in the air vent
-
What is a distinguishing factor in a vapour system?
vacuum is created
-
What will occur if the automatic water feeder cannot keep up with the rate of steam evaporation from the boiler?
the low water cut-off will shut off the fuel souce
-
What could result if a high water level reduces the available steam space at the top of the boiler?
priming and carryover, with possible water hammer
-
What does an End of Main vent do?
a single port that has a much larger venting capacity than a radiator vent. Vents out air in the system.
-
Specs of an end of main vent...
- - at least 15" from end of pipe
- - 6"-10" high nipple on dry return.
-
What should lift fittings be limited to?
- - 5 feet
- - not used on a differential vacuum heating system
-
What is key when two LPS boilers are on one system?
water levels must be balanced
-
What is carryover in a LPS boiler?
condition when boiler water is removed from the boiler and sent into the steam mains. Foam is created by grease ad dirt and can start the priming action that will actually suck water fom the stem drum into the main,
-
The flow of water or other fluids into the distrubution pipes of a potable water supply fom ny soure other than that its intended source and tha could be produced by the differential pressure existing bretween two systems and may exist at pressures that are greater or lower thn atmospheric pressure is called?
what is backflow
-
The reversal of the normal diretion of flow in a pipeline due to a negative pressure being created in the supply line when the backflow source is subject to atmospheric pressure is referred to s:
backsiphonage
-
The reversal of the normal direction of flow in a water supply caused by a condition in which the pressure in the system being supplied becomes greater than the pressure in the supply main which is above atmospheric pressure is called:
backpressure
-
The termination of a clear water waste discharge line at a point above the flood level rim of a floor drain, etc, installed so that it prevents backflow/backsiphonage is called:
an airbreak
-
The unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet conveying potable water to any recptale and the flood-level rim of the receptacle is called
air gap
-
What are the "degrees of hazard" of a potential or actual cross-section?
minor, moderate, severe
-
What is the simplest and most effective method used to prevent a cross-connection?
the air gap
-
When a sever hazard of cross connection exists, and an air gap is impractical, what should be used/
RP
-
According to the AWWA code, Ch. IV, domestic heating systems not containing any chemical additives may use a _________ for backflow protection.
dual check with atmospheric port (DCAP)
-
1 BHP=
- 34.5;b of steam/hr or
- 33,475 BTUH
-
High pressure steam boilers are rated in:
BHP, MBH, lbs steam/hr
-
What is conduction?
Heat from a heating medium (steam, hot water) is transferred to antoher material (metal) and in turn to a heated medium (water, oil)by conduction
-
Define radiation.
process of emitting energy in the form of waves or particles.
-
Define convection.
relies on the natural air currents caused by differences in temps of the air contained in a heating space.
-
Blow through unit heaters should be installed _______ max.
6-12 ft
-
Draw through unit heaters can be_____ high
20feet
-
What can scale build up in hot water lines cause?
acts as insulation and reduces heat transfer
-
What type of glycol must we use?
propylene glycol
-
When do glycols start to break down?
at 250'F, the oxygen within oxidizes and produces an organic acid
-
Some considerations when using glycol?
- expands more than water, 15-20% more.
- takes more energy to heat glycol over simple water
-
Reduced-pressure principle backflow preventer
-
What are the two primary purposes of steam?
- do work (high pressure steam)
- transport heat energy (low pressure steam)
-
Define steam trap.
an automatic valve that is designed to remain closed and hold back steam and to open to allow condensate and non-condensable gases to pass through the valve.
-
What are some factors to consider when choosing a steam trap?
- - presence of air or non-cond gases
- - rate/amount of condensate
- - pressure differential btw supply/condensate mains
- - variations in condensate loads
- - frequency of usage of system
- - use of dry or wet returns
- - possibility of creating water hammer
-
What do drip legs do?
create larger cross-sectional opening in the pipe. Causes steam to lose some velocity as it passes over the opening. Both air and heavier condensate drop out of te steam at this point.
-
Is there a universal steam trap?
NO
-
Define a Thermostatic steam trap.
actuated by the difference in temperture of the condensate and steam flowing in the trap. Cool condensate or non-condensable gases open the trap, hotter steam closes it.
-
Define Thermodynamic steam traps.
utilizes the energy released as condensate flashes to steam as it moves from the high-pressure inlet side to the low-pressure outlet area.
Commonly used with high-pressure steam.
-
Define Mechanical steam trap.
also called density trap. depends on difference in density of steam and condensate and upon the movement of a float or bucket for their operation
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