| (2) When a low-water cutoff, and/or alarm is housed
in either the water column or a separate chamber, it shall be provided
with a blowdown pipe and valve not less than 3/4 inch nominal pipe
size (20 mm). The arrangement shall be such that when the water column
is blown down, the water level in it will be lowered sufficiently
to activate the low-water cutoff and/or alarm device.
(3) Should a steam collection or liberation drum of
a process steam generator be installed in a system without a local
and constant attendant, and it is not a failsafe design, it shall
be provided with a low-water cutoff as required for power boilers.
(h) Pressure gages.
(1) Each steam collection or liberation drum of a process
steam generator shall have a pressure-indicating device that is readable
from the primary operating station. The range shall be graduated to
approximately double the pressure at which the safety valve is set,
but in no case, less than one and one-half times this pressure. The
pressure-indicating device shall be connected to the steam space,
or to the water column, or its steam connection. A valve or cock shall
be placed in the gage connection adjacent to the gage. An additional
valve or cock may be located near the steam collection or liberation
drum of the process steam generator. No other shutoff valves shall
be located between the gage and the steam collection or liberation
drum of the process steam generator. The pipe connection shall be
of ample size and arranged so that it may be cleared by blowing down
or flushing. The pressure-indicating device shall be provided with
a siphon or equivalent device, which will develop and maintain a water
seal that will prevent steam from entering the pressure-indicating
device.
(2) Each steam collection or liberation drum of a process
steam generator, shall have a valved connection at least 1/4 inch
nominal pipe size (8 mm), connected to the steam space for the purpose
of attaching a test gage when the process steam generator is in service,
to test the accuracy of the pressure-indicating device.
(i) Stop valves.
(1) Each steam outlet from an ASME Code, Section I,
process steam generator, shall be fitted with a stop valve located
as close as practicable to the steam collection or liberation drum
of the process steam generator.
(2) When a stop valve is located that allows water
to accumulate, ample drains shall be provided. The drain shall be
piped to a safe location and shall not be discharged on the process
steam generator or its setting.
(3) When boilers that are provided with manholes or
other similar openings that permit access for human occupancy are
connected to a common steam main, the owner or operator shall ensure
that the boiler to which entry is being made is completely isolated
from the steam main. This may be accomplished with the use of two
stop valves with an ample drain between them, with a full isolation
blind or removal of piping such that the boiler is no longer connected
to the steam main.
|
| Source Note: The provisions of this §65.609 adopted to be effective June 15, 2015, 40 TexReg 3121; amended to be effective February 15, 2016, 41 TexReg 795; amended to be effective January 15, 2018, 43 TexReg 75; amended to be effective February 15, 2019, 44 TexReg 583 |
