Page 10
GV100W BOILER
INSTALLATION & OPERATING INSTRUCTIONS
FIG. NO. 5 Heating System Piping
DISCHARGE PIPE SIZE TO EQUAL VALVE OUTLET. DO NOT RESTRICT FLOW.
SUPPORT DISCHARGE PIPING
SO AS TO AVOID STRAIN ON
THE VALVE BODY.
FOR DISCHARGE
THROUGH ROOF
CONSULT THE
SMITH CO.
1" CLEARANCE MUST BE MAINTAINED BETWEEN HOT WATER PIPING AND COMBUSTIBLE CONSTRUCTION.
DISCHARGE SO AS TO AVOID EXPOSURE OF PERSONS TO HOT LIQUID OR VAPOR. L EAVE OPEN END VI SIBLE FOR PERIODIC INSPECTION FOR SLOW LEAKAGE OR DRIPS.
System Bypass
For systems using a circulator on the return as either a single zone, or multiple zones with zone valves, install a system bypass line between the supply and return on the suction side of the circulator, see FIG. NO. 6. Install a metering valve in this bypass line to regulate the amount of flow that will be diverted to the return. A plug valve offers the best control for this application. Although other valves may be less expensive, a plug valve will be easier to set accurately.
Pump Away Bypass
For systems that use a single circulator to pump away from the boiler, the bypass should be installed on the discharge side of the circulator, see FIG. NO. 7. Full temperature water supplies the baseboard distribution system as before. Half of the circulator’s volume moves through the bypass, blending and heating the cooler return water. Again, the cost of installing the bypass is small and setting it by temperature can be accomplished with a contact thermometer.
In the absence of a flow indicator, set the metering valve using FIG. NO. 7 temperature as a guide. The accompanying diagram suggests
one scenario. This addition requires only two tees, a plug valve, and a small amount of pipe and offers the simplest approach to reliably control condensation. For this system and those that follow, be aware that you are using a percentage of the pump capacity to blend, but the friction loss for the entire pump flow has been reduced. In most cases, the standard pump packaged with the boiler has enough capacity to feed the baseboard distribution system and the bypass line.
FIG. NO. 6
SUPPLY | RETURN | |
50% |
| 50% |
| 120° F | |
160° F |
| |
|
| |
| 50% |
|
100% | 160° F | 100% |
| ||
160° F |
| 140° F |
SUPPLY | RETURN | |
50% | 50% | |
120° F | ||
160° F | ||
| ||
| 50% | |
| 160° F | |
100% | 100% | |
160° F | 140° F |
PUMP AWAY
BYPASS
SYSTEM BYPASS
