INST 6006 - Heating Boiler Operating Controls (Chp 8) Flashcards
A manual “high-low” switch should be switched to “high” or “auto”:
A) When the pressure is too low
B) Prior to ignition of the main flame
C) As soon as the main flame has stabilized
D) When the boiler has been properly warmed up
E) During the boiler pre-purge
D) When the BOILER has been PROPERLY WARMED UP
A levelling indicator is found on:
A) A low water fuel cut-off switch B) A boiler feedwater pump C) The casing of a heating boiler D) A modutrol motor E) An on-off pressure control switch
E) An on-off pressure CONTROL SWITCH
In a hot water heating system, the water temperature must never exceed:
A) 110°C B) 100°C C) 80°C D) 60°C E) 121°C
E) 121°C
Quickly closing the main burner manual cock valve during boiler operation should check the:
A) High gas pressure fuel cut-off B) Low fire interlock switch C) Flame Scanner D) Low gas pressure fuel cut-off E) Combustion air proving switch
A) HIGH GAS pressure fuel cut-off
Code requirement maximum setting for a high limit control on a steam heating boiler is:
A) 68.9 kPa (10 psi) B) 862 kPa (125 psi) C) 35 kPa (5 psi) D) 207 kPa (30 psi) E) 103 kPa (15 psi)
E) 103 kPa (15 psi)
Maximum Setting for High Limit Control
Modulating burner controls operate by regulating:
A) Fuel temperature and air flow B) Fuel flow and atomizing steam flow C) Steam flow and fuel flow D) Fuel flow and air flow E) Fuel flow, air flow, and feedwater pressure
D) FUEL flow and AIR flow
NOTE: FUEL and AIR
The high steam pressure fuel cut-off:
- Requires an isolation valve for maintenance.
- Is exposed to boiler steam
- Requires a water seal between it and the boiler
- Needs to be reset after each operation
A) 1, 2 B) 2, 3 C) 1, 2, 3, 4 D) 2, 3, 4 E) 3, 4
E) 3, 4
Keyword: Water Seal,Reset
A high limit control switch:
A) Must be used when a boiler is not under continuous supervision
B) Activates after the safety valve opens
C) Is a normally open switch
D) Is necessary on all boilers
E) Usually does not require manual resetting
A) Must be used when a boiler is NOT UNDER CONTINUOUS SUPERVISION
The main concern of the boiler operator is to operate a boiler:
A) Without need for water treatment
B) As economically as possible
C) As quietly as possible
D) As safely and as efficiently as possible
E) With the water level as high as possible
D) As safely and as efficiently as possible
An on-off steam boiler:
A) Will maintain a fairly constant steam pressure
B) Cannot operate in a multi-boiler system
C) Must have a low capacity
D) Operates most efficiently at continuous firing
E) Will cycle on and off based on a regular timed cycle
D) Operates most efficiently at CONTINUOUS FIRING
A high gas pressure fuel cut-off switch:
A) Is a normally open switch B) Is never a manual reset device C) Opens when gas pressure is too high D) Closes when gas pressure is too high E) Must be located upstream of an automatic fuel valve
C) OPENS when gas PRESSURE IS TO HIGH
Ideally, the cut out pressure of the high limit control of a steam heating boiler should not exceed:
A) 95% of the safety valve setting B) 100% of the safety valve setting C)90% of the safety valve setting D) 75% of the safety valve setting E) 80% of the safety valve setti
C)90% of the safety valve setting
A safeguard is a device or mechanism for ensuring safety. An example of a Safeguard is:
A) Low Gas Pressure Fuel Cut-Off Switch B) Everything listed here C) High Steam Pressure Fuel Cut-Off D) Low Air Pressure Fuel Cut-off E) Low Water Level Fuel Cut off
B) Everything listed here
NOTE:
LOW GAS,HIGH STEAM,LOW AIR,LOW WATER
Operating controls for hot water boilers are not operated by:
A) Liquid expansion B) Sensing bulb and capillary tube C) Water temperature changes D) Steam Pressure E) Bellows controls
D) Steam Pressure
Common control switches found on low-pressure heating boilers may include:
A) Low and high fire switches B) Damper positioning switch C) Auto-manual selector switch D) All switches described here E) Flame control switch
D) All switches described here
