7 Controlling Utilities And Building Systems Flashcards
Natural Gas control valve configuration for larger occupancies
May be on horizontal or vertical feed to meter, maybe rectangular quarter turn, may be larger square nut turned with wrench.
In many large industrial properties, gas meters are located where
Inside underground vaults or in utility rooms inside building.
Dot erg recommended distance from possible Bleve
At least 1/2 mile
On large fixed installation horizontal lpg tanks, control valves may be located where
Side of tank or in manifold box at the end
Where lpg tanks are grouped together horizontally, the flow may be controlled fro. Where
Controlled from central manifold location
Oil tanks may be mounted above ground on stanchions to increase
Flow pressure from gravity
Jurisdictions usually require above ground oil tanks be protected by
Surrounding with earthen dike or other containment means
Bleve in a fuel oil tank is
Not common but possible
Oil pressure in boiler atomizer for maximum efficiency
600-1000 psi
If the oil tank gate vale is inoperable or inaccessible how can you stop flow of oil
Crimp line. With pliers or hydraulic tool
During white ghost (amazed fuel oil atmosphere) emergency what should be done
Evac building, shut off emergency power switch, vent, eliminate ignition sources, avoid entering vapor cloud
Approaching scene of possible leak in apparatus should be done from where
Upwind, apparatus is possible ignition source. Stage as much as a block away
Dot erg recommended staging distance for gas leak
160-330 feet
In determining a perimeter distance, a safe distance is a judgement made by who
By the IC based on information gathered and accurate assessment of hazard.
A perimeter should be marked with
Caution or fire line tape.
If firefighters established the initial perimeter, who should they pass control of the perimeter to asap
Law enforcement
Most common fuel control problem faced during structure fire
Securing gas utility
One way of establishing a control zone for gas leak
Move with cgi from a point with no readings toward suspected leak sampling at frequent intervals until reading registers.
Natural gas leas should be metered at what elevation
Waist high and up
Since the lel for NG is at 5 percent, many fire departments establish a perimeter at
10% of that figure, 0.5%, but lel propane is 1.5% so it should be no more than 0.15%
Control zone perimeter is generally established where
a point at which the first detectable reading appears.
Lpg monitoring should be taken at what elevation
Close to the ground.
Lpg may leak as a white cloud if
Humidity is high enough
Firefighters are generally able to shut of gas at outside control valves and meters but not
Underground
Isolation of ignition sources during gas leak
Work from outside in, eliminating ignition sources and turning off gas service, putting out the pilot light as a result.
Two most common electrical emergencies
House fires
Downed wires
Turbine and photovalic solar panel service shut offs are most likely located where
Near the main electrical panel
Finding the right electrical switch in a commercial occupancy may be difficult because
There may be multiple subpanels
Large commercial breakers or switches can cause what when opened
An arc, possible ignition source, or damage eyes while looking at it
While securing industrial power service, ff must rely on who
Service and maint personnel from industrial site
If the amount of downed wires taxes a departments resources, how can they be managed
By condoning off the area and moving on to the next wires down
Establishing a perimeter around downed lines may be as simple as
Placing traffic cones around the hazard zone to direct people and motor vehicles around
Recommended isolation distance in downed wires
One full span between adjacent poles or towers in all directions from point of contact with ground.
Alternating current detectors
Tac sticks / hot stick
With an AC current detector, the range is dependent on
The line voltage
Under ideal conditions ac detectors can detect a single 120 v line from as far as
15 feet away, but if on wet soil as little as 1 ft
Circuit breakers for power substations will reset several times during service interruptions resulting in
Intermittent loss and and energizing, causing misleading indication of dead power line
A thermal imaging camera can be used to detect downed wires because of
The thermal energy generated from the electrical resistance of the wire touching something.
When water fills a basement it can cause
Short circuit of electrical outlets and services, and extinguish pilot lights
Shutting off building water service can
Stop sprinklers and standpipes, leading to fire spread
Sprinkler systems can be shut off after fire control efforts and then
Sprinkler heads Plugged and water turned back on
Unless the water supply in a sprinkler system is contributing to fire suppression efforts, it should be
Shut off asap
The only reason to delay shutting off a sprinkler system at the appropriate time is
Due to resource limitations and other, higher, fire ground priorities.
Water main shut offs to residences are usually located
Between water meter and building or between well service and building
In larger multiple residence buildings and other large buildings, main water valves are often
Sub surface gate valves located in the street or sidewalk.
If a sub surface valve is closed too quickly, it can cause
Damage to the main
Water hammer and seismic events can cause
Rupture of plumbing
Water leaks in houses can go undetected for a while because of
Insulation in walls and ambient noise
First indication of water leaks are often
Lights failing or flickering, thermostat not responding.
