Technical Drawing

BURNHAM COMMERCIAL 27 February 2008
MPC Multiple Pass Commercial Boiler – Suggested Specifications
Heating, Ventilating and Air Conditioning
15500-2
2.3 PRODUCTS:
A. 3-PASS CAST IRON BOILER – MODEL MPC
1. Hot water boiler shall be a high efficiency, pressurized, cast iron sectional wet base
boiler and not require a refractory combustion chamber. It shall be suitable for forced
draft firing and capable of achieving a minimum combustion efficiency of 88% fired
with No. 2 oil and 85% fired with gas. Thermal efficiency shall be a minimum of 86%
with No. 2 oil and 83% fired with gas. Heat transfer shall be enhanced by the addition
of removable baffles.
2. Boiler shall be a 3-pass cast iron sectional type design with large combustion chamber
and horizontal flue passes with cast fins. Class 25 high silicone content cast iron shall
provide resistance to temperature variations and thermal stress. A high-temperature
silicone-coated fiberglass rope gasket will be compressed into a cast tongue and groove
connection around the perimeter of the section, providing a durable, gas tight seal.
3. Boiler shall have a return mixing tube with drilled openings in each section, allowing
proportionate distribution of return water throughout the entire section assembly. Cool
return water shall be pre-heated by the hot supply water as it enters the section assem-
bly thereby reducing thermal stress on individual sections without the use of external
mixing devices. Boiler supply water temperatures, measured on the supply manifold
shall be no less than 130ºF. Return water coming back to the boiler may be no less
than 80ºF. System piping shall be sized for a maximum temperature difference be-
tween the boiler supply and return water of 40ºF. However, a maxiumum delta T of
80ºF across the boiler is allowable.
4. A single supply water manifold shall be located at the rear of the boiler with eight tap-
pings for the installation of temperature and pressure controls, gauges, probe-type low
water cut-offs, and electronic control sensors. A single top rear return connection shall
be considered standard equipment.
5. Boiler shall be furnished as a knocked down unit for field erection. Sections shall be
assembled using precision machined cast iron push nipples.
a. [USE FOR FACTORY PACKAGED] Boiler shall be factory assembled and
installed on a structural steel frame/base, completely packaged with burner and
controls mounted and wired. Section assembly shall be hydrostatically pres-
sure tested @ 120 PSI prior to shipment. Packaged boiler shall be shrink
wrapped for protection.
b. [USE FOR FACTORY PACKAGED AND FIRE TESTED] Boiler shall be
factory assembled and installed on a structural steel frame/base, completely
packaged with burner and controls mounted and wired. Burner shall be factory
fire tested to ensure proper operation before shipment. Boiler jacket shall bear