Section 2 — Installation
2-18 Part No. 750-363
2.9 MINIMUM BOILER OVERPRESSURE
To prevent the occurrence of flash steam within the boiler or system, hot water boilers must operate with
proper over-pressure. System over-pressure requirements are shown in Table 2-8.
Note: The ASME Code Section IV limits the maximum setting of the excess temperature control to 250 F (121 C). This is to ensure
that water temperature will not reach the boiling point (steaming) and therefore, so as not to exceed the maximum limit of this
control and in compliance with the Code, the operating limit of 230 F (110 C) is set for normal boiler operation.
While proper overpressure is required, a means to relieve excess pressure at or beyond the design pressure of
the boiler must be provided. As boiler water is heated, expansion occurs. And this expansion must be
accounted for either with an expansion tank (air filled) or with a bladder type tank. These devices permit the
water pressure to expand outside of the boiler and not impact the pressure vessel or pressure relieving
device. In accordance with code, each boiler is equipped with an ASME approved safety relieving device
should pressure build-up occur.
Table 2-10: Model CFLC Minimum Over Pressure Requirements (100% water)
2.10 CONDENSATE REMOVAL AND TREATMENT
The condensate generated during normal boiler operation must be removed in accordance with local codes
and regulations. The condensate can be piped to a local treatment system or run into the optional
condensate treatment assembly.
The water trap must be filled with water prior to commissioning and checked or refilled at each required
maintenance interval.
Notice
The condensate occurring during operation in both the boiler and the flue gas pipeline should be neutralized and piped
to a safe drain. The conditions for the discharge of condensates into public drain systems are determined by the local
authorities and municipalities.
Condensate leaving the boiler normally has a pH of 4-6. The responsible authority will inform you if a higher
pH value is required for condensate piped to drain. The CFLC neutralization system contains a compound
which acts to increase the pH of the condensate flowing through it. The neutralization system comprises
the plastic neutralization tank with condensate inlet, granulate chamber and condensate outlet. The system
is installed per Figure 2-11.
Outlet Water Temperature Minimum System Pressure
(°F) (°C) PSIG Bar
130-180 54-82 12 0.83
181-185 83-85 15 1.03
186-205 86-96 18 1.24
206-215 97-101 24 1.66
216-225 102-107 30 2.07
226-240 108-116 42 2.90
To Next Page
Loading...