Burnham CHG225 - Manual (Page 23)

23
Ix System Piping
A. General System Piping Precautions
CauTION
ThE hEaT ExChaNgEr usED IN ThE Chg Is maDE frOm a sPECIal alumINum allOy.
FAILuRE To TAkE THE FoLLoWING PRECAuTIoNS CouLD RESuLT IN SEVERE BoILER
DamagE aND wIll VOID ThE maNufaCTurEr’s warraNTy.
• INSTALL BOILER SO THAT THE GAS IGNITION SYSTEM COMPONENTS ARE PROTECTED FROM WATER
(DRIPPING, SPRAYING, RAIN, ETC) DURING APPLIANCE OPERATION AND SERVICE (CIRCULATOR
REPLACEMENT, ETC).
• OPERATION OF THIS BOILER IN A SYSTEM CONTAINING SIGNIFICANT AMOUNTS OF
DISSOLVED OXYGEN CAN CAUSE SEVERE HEAT EXCHANGER CORROSION DAMAGE.
• USE ONLY ANTIFREEZE SPECIFICALLY PERMITTED ON PAGE 39 OF THIS MANUAL.
• MAKE SURE THAT THE WATER USED TO FILL THE SYSTEM MEETS THE REqUIREMENTS OUTLINED
IN THE START-uP AND CHECkouT SECTION XI OF THIS MANUAL.
• NEVER USE PETROLEUM BASED CLEANING OR SEALING COMPOUNDS IN THE BOILER SYSTEM.
THESE PRODUCTS COULD DAMAGE ELASTOMER SEALS AND GASKETS IN THE SYSTEM AND COULD
RESULT IN PROPERTY DAMAGE.
• THIS BOILER IS NOT DESIGNED FOR USE IN SYSTEMS CONTAINING SIGNIFICANT AMOUNTS OF
MAKEUP WATER. REGULAR ADDITIONS OF MAKEUP WATER MAY CAUSE SEVERE HEAT EXCHANGER
DAMAGE.
• BEFORE CONNECTING BOILER, MAKE SURE THAT THE SYSTEM IS FREE OF SEDIMENT, FLUX AND
ANY RESIDUAL BOILER WATER ADDITIVES. FLUSH THE SYSTEM IF NECESSARY TO ENSURE THAT
THESE CONTAMINATES ARE REMOVED.
• MAINTAIN THE PRESSURE IN THE BOILER AT A MINIMUM OF 12 PSI.
• DESIGN SYSTEM TO ENSURE THAT THE FLOW FALLS WITHIN THE LIMITS CALLED FOR IN TABLE 8.1.
• THE MAxIMUM ALLOWABLE LOAD IS 20 kw (68 MBTU) PER CENTER SECTION AND 10 kw (34 MBTU)
PER END SECTION WITH LOAD BASED ON NET CALORIC VALUE. THIS EqUATES TO 75,000 BTU/HR
GROSS CALORIC INPUT FOR CENTER SECTION AND 37,500 BTU/HR GROSS CALORIC INPUT FOR AN
END SECTION.
• MAxIMUM ALLOWABLE DELTA T BETWEEN SUPPLY AND RETURN DURING OPERATION IS 45°F AT
MAxIMUM LOAD AND 63°F AT MINIMUM LOAD.
• THE PRODUCT SHALL AT ALL TIMES BE FILLED WITH CLEAN POTABLE WATER. THE ONLY
ALLOWABLE ADDITIVES ARE THE FERNOX PRODUCTS, ALPHI II (ANTI FREEZE), SUPERFLOC
(CLEANING), AND COPAL (ANTICORROSION) OR EqUIVALENTS. THE CHEMICAL ADDITIVES MUST
BE USED IN ACCORDANCE WITH THE CHEMICAL MANUFACTURERS RECOMMENDATIONS FOR USE
WITH ALUMINUM BOILERS AT ALL TIMES. THE pH OF THE SYSTEM HYDRONIC FLUID MUST BE
MAINTAINED BETWEEN 6.0 AND 8.5.
• THE MINIMUM ALLOWABLE WATER FLOW BASED ON A 5/1 TURN DOWN RATIO FOR HEAT INPUT
WITH THE MINIMUM FLOW CORRESPONDING TO MINIMUM FIRING RATE HEAT INPUT IS AS
FOLLOWS; CHG3 - 3 GPM, CHG4 - 5 GPM
B. System Design
Proper operation of the CHG boiler requires that the water flow through the boiler remain within the limits shown in
Table 8.1 any time the burner is firing. Failure to maintain the flow within these limits could result in erratic operation
or premature boiler failure. There are three basic methods that can be used to pipe the CHG boiler. The instructions on
the following pages describe three alternative methods for piping CHG boilers and explain how to size the circulator
and piping for each one. Additional information on hydronic system design may be found in Installation of Residential
Hydronic Systems (Pub. #200) published by the Hydronics Institute in Berkeley Heights, NJ.
Table .1: Flow requirements Through Boiler
BOILER MODEL
MIN. REqUIRED FLOW
(GPM)
MAX. ALLOWABLE
FLOW (GPM)
CHG150 6 15
CHG225 9 23