Gas Equipment & Large Boiler 248 CMR 7.00 Flashcards
Burner assemblies and all component parts shall be installed according to the ______.
manufacturers instructions and shall be properly and firmly secured in place to maintain correct alignment in normal use.
A low-water cutoff may be bypassed for what reason?
for blow down purposes only.
Linkage for controlling air and gas input rates are designed to ______.
reliably maintain correct air-gas ratio.
What is the primary function of a boiler limit control?
to prevent excessive steam pressure in a steam boiler or excessive temperature or pressure in a hot water boiler.
When shall combustion control be provided?
for burners with a firing rate of 2,500,000 BTUs per combustion chamber per hour and over
An electric ignition system shall ignite only…?
a pilot
What shall an air shutter be capable of?
being readily adjustable to any desired setting and securely locked to prevent accidental change in setting.
A pressure-operated safety shutoff valve shall close…?
upon failure of its operating pressure
How close to the entrance of a gas train must the gas shutoff be?
within 6 feet
An electrically operated safety shut-off valve shall not _____
depend on electricity to shutoff the gas supply
Natural and mechanical draft systems with continuously burning pilot(s) capable of igniting any gas flowing from the main burner shall, upon demand for heat, ______
prove all interlocks
Natural draft systems with intermittent pilot or interrupted pilots, upon demand for heat shall ______
1.) prove all interlocks
2.) prove open for at least 90 seconds
Gas main pressure regulators and gas pressure interlocks. Each burner assembly shall be equipped with a ___(A)___ main gas pressure regulator that will regulate within ___(B)___.
(A) listed
(B) plus or minus 10% of the operating pressure at all firing rates.
Except where zero governors are used in connection with air-gas mixers, all main gas pressure regulators shall be ______.
vented independently to a safe outdoor location
Vent lines from main gas pressure regulators shall not be connected into a ___(A)___ with the bleed line from gas operated ___(B)___.
(A) common line
(B) diaphragm valves or from pressure relief valves
What 3 materials can be used for vent lines?
1.) steel
2.) wrought iron pipe
3.) Corrugated stainless steel tubing (CSST)
Vent lines shall extend no less than ______ above the roof surface.
18 inches
vent lines shall be run to the outside using ___(A)___ and shall not be ___(B)___.
(A) shortest practical route
(B) trapped or installed in a manner that restricts air flow
CSST vent lines shall transition to steel no less than ______
one foot inside the building
Vent lines that terminate a building opening shall be located no less than ______
4 feet away from any building opening or air intake.
Name 3 things for pilot testing.
1.) pilot burner shall be lighted and adjusted to manufacturers instructions
2.) pilots shall not deposit carbon
3.) when bleed pilots are used the discharge shall be in a fixed position
complete written or printed instructions including wiring diagrams shall be ______.
supplied and made conveniently available or posted in permanent form near the equipment.
