Maintain Boilers & Ancillary Equipment Flashcards
(38 cards)
The average boiler consumes more than ?? times its initial cost in fuel every year
four
What is The purpose of a boiler inspection
provide assurance of equipment integrity to minimize safety issues with operating a pressure vessel
Maximum service intervals
1-High press boiler and low press steam boiler
2-low press hot water boiler and unfired boiler
3-Low press organic fluid boiler
1- external-1 year internal- 2 year
2- external- 2 year internal-4 year
3- external-2 year internal-3 year
Inspection should be made three months after initial starting and at regular 6-, 9-, or 12-month intervals thereafter for what
chemical analysis of the boiler water on a pressure vessel
What is the leading cause of deterioration of the pressure vessel
Improper water treatment
If excessive mud of sludge is noticed during the blowdown what should be done
Clean it and the scheduling or frequency of blowdown may need to be revised
When shutting down the boiler, the load should be what
be reduced gradually and the pressure vessel cooled at a rate that avoids damaging temperature differential that can cause harmful stresses.
Draining the unit too quickly may cause what
the baking of deposits that may be present on the heating surfaces
What is an hydrostatic test
Pressureize the boiler loops and check inside the boiler for leaks
What inspection should occur with the owner/operator present
The waterside
Scale on tubes can cause what issues
which not only results in lower operating efficiency, but more importantly, can cause overheating of boiler metal
stack temperatures will be elevated
Water treatment is under the control of who
the power engineer
When your done the water side inspection the pressure vessel interior should be flushed out how
with a high pressure hose
In extreme cases, it may be necessary to resort to acid cleaning
Extreme scale build up in a water tube boiler will do what
impede water flow through the heat exchanger
This is especially problematic on coil tube designs
If a scaling problem exists, it will probably be more noticeable where
where the feedwater enters the boiler
What will result as the soot blanket insulated the tubes
Elevated stack temperatures
What tool can help wash soot out of a heat exchanger
soot washing lances
Which gas will experience a build up of a white coating on the fireside of the tubes
Boilers firing Digester gas
When you are satisfied with the cleaning of the waterside what do you do next
Replace all waterside handhole and manhole gaskets
The LWCO gaskets can be sprayed lightly with what
never-seez to facilitate easier gasket removal next inspection
why shouldnt you store serviced valves on the shelf
time is expiring
Pressure relief devices Max service dates
1-power boiler
steam above 15 psi
HW above 121 degrees Celsius
2-Heater boiler
HW 121 degrees celsius and below
Steam up to 15 psi
1- press test 1 year
max service 5 year
2- press test 2 year
manual lift (steam) 1 year
max service ( HW) 6 year
Max service (steam) 5 year
Pop test on safety relief valve
Do not hand operate the valve with less than ?% of the stamped set pressure exerted on the underside of the disc
75
Repair of a safety relief valve must be done only by
by the manufacturer or his authorized representative
