Current through Register Vol. 50, No. 25, December 15, 2023
A. Feedwater Connection.
(1) Feedwater, make-up water, or water
treatment:
(a) Shall be introduced into a
boiler through:
(i) The return piping system,
or
(ii) An independent feedwater
connection that does not discharge against a part of the boiler exposed to
direct radiant heat from the fire;
(b) May not be introduced through an opening
or connection provided for:
(i) Inspection or
cleaning,
(ii) Safety
valve,
(iii) Safety relief
valve,
(iv) Surface
blowoff,
(v) Water
column,
(vi) Water gage
glass,
(vii) Pressure gage,
or
(viii) Temperature
gage.
(2)
Feedwater pipe shall have a:
(a) Check valve
near the boiler; and
(b) Stop valve
or cock between the check valve and the boiler or return pipe system.
B. Pressure or Altitude
Gage.
(1) A hot water boiler shall have a
pressure or altitude gage connected to the boiler or its flow connection so
that it cannot be shut off from the boiler except by a cock with a tee or lever
handle:
(a) Placed on the pipe near the gage;
and
(b) With the handle parallel to
the pipe in which it is located, when the cock is open.
(2) The scale on the dial of a pressure or
altitude gage shall be graduated to indicate pressures from 1-1/2 to 3 times
the maximum allowable working pressure.
(3) Piping or tubing for a pressure or
altitude gage connection smaller than 1 inch pipe size shall be of nonferrous
metal.
C. Steam Gage.
(1) A steam boiler shall have a steam gage
connected to its steam space, water column, or steam connection by a siphon or
equivalent device on the exterior of the boiler.
(2) A siphon shall be:
(a) Of sufficient capacity to keep the gage
tube filled with water; and
(b)
Arranged so that the gage can be shut off from the boiler only by a cock with a
tee or lever handle:
(i) Placed in the pipe
near the gage, and
(ii) With the
handle parallel to the pipe in which it is located, when the cock is
open.
(3)
Scale.
(a) The scale on the dial of a steam
gage shall be graduated to at least 30 PSIG.
(b) The gage shall have effective stops for
the indicating pointer at the:
(i) Zero
point; and
(ii) Maximum pressure
point.
(c) The travel of
the pointer from zero to 30 PSIG shall be at least 3 inches.
D. Stop Valve and Check
Valve.
(1) A boiler which can be closed off
from the heating system by closing a steam stop valve shall have a check valve
in the condensate return line between the boiler and the system.
(2) Any part of a heating system that can be
closed off from the remainder of the system by closing a steam stop valve shall
have a check valve in the condensate return pipe from that part of the
system.
E. A hot water
boiler shall have a thermometer located and connected so that:
(1) A person observing the water pressure or
altitude gage can read the thermometer easily; and
(2) The thermometer at all times indicates
the temperature, in degrees Fahrenheit, of the water in the boiler at or near
the outlet.
F. Water
Gage Glass.
(1) A steam boiler shall have at
least one water gage glass attached to the water column or boiler by valved
fittings.
(2) The lower fitting
shall have a straightway drain valve with an opening at least 1/4 inch diameter
to facilitate cleaning.
(3) Gage
glass replacement shall be possible while the boiler is under
pressure.
(4) Transparent material
other than glass may be used for a water gage if the material is suitable for
the pressure, temperature, and corrosive conditions encountered in
service.
G. When
practicable, a boiler equipped with a condensate return pump shall have a water
level control that automatically maintains the water level in the boiler within
the range of the gage glass.
H.
Repairs and replacements of fittings or appliances shall comply with the ASME
Code for new construction, Section IV.
I. The ASME Code, Section VI, Recommended
Rules for the Care and Operation of Heating Boilers is recommended as a guide
for proper and safe operating practices.
J. It is recommended that a return water
connection to a low-pressure steam heating boiler supplying a gravity return
heating system be arranged to form a return pipe loop connection, so that water
cannot be forced out of the boiler below the safe water level, as shown in
Section IV, Figure HG-703.1 of the ASME Heating Boiler Code.
Regulations .12 adopted
effective June 1, 1989 (16:10 Md. R. 1106)
