Flow And Return Pipe Connections; Pressure Relief Valve - Watts AERCO Modulex EXT Commercial Series User Manual

Modulex EXT Commercial Series Boilers User Manual
CHAPTER 4: Installation Instructions

4.10 FLOW AND RETURN PIPE CONNECTIONS

The cold and hot water flow and return circuits must be connected to the boiler via the
respective 4" M and R connections as indicated in Table 2-1.
When determining the size of the cold/hot water circuit pipes it is essential to bear in mind the
pressure losses induced by any of the system's components and by the configuration of the
system.
When planning the routing of the cold/hot water piping, take the necessary precautions to avoid
air traps and pockets and to facilitate the continuous purging of the system.
WARNING!
Before installing the boiler we recommend that the system is flushed out with a suitable
cleaning product in order to eliminate any metallic tooling or welding residues, or oil and
grime, which could reach the boiler and affect the proper functioning of the boiler.
Ensure that the system piping is NOT used for earth grounding of electrical or telephone
systems. Such grounding of system piping is unsuitable and can cause serious damage
to the piping, boiler, and radiators.
IT IS ABSOLUTELY FORBIDDEN TO FIT ON-OFF VALVES IN THE PIPING BEFORE
THE REQUIRED SAFETY DEVICES.

4.11 PRESSURE RELIEF VALVE

Each unit is delivered with a 1-1/2 inch, 80 psi Pressure Relief Valve that complies with the
ANSI/ASME ANSI Z21.13 / CSA 4.9 Boiler and Pressure Vessel Code, Section IV (''Heating
Boilers''), and CSA B51, Boiler, Pressure vessel, and Pressure Piping Code, as applicable.
NOTE:
Lower system pressures require lower rated Pressure Relief Valves (not supplied).
On newer EXT models (with aluminum headers) the Pressure Relief Valve is factory installed
inside the chassis.
IMPORTANT!
Discharge piping MUST be installed at the relief valve discharge. The discharge piping must
be installed in accordance with localcodes.
On older models, the Pressure Relief Valve is not factory installed, but instead included
separately in the shipping container. It must be fitted on the CSD-1 manifold at the site, per the
instructions in the next section, 4.12 (see Figure 4-6).
OMM-0095_0H
GF-139
(Image removed)
Figure 4-5: Pressure Relief Valve
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
Page 33 of 144
09/15/2017