Specifications

| 15
Indirect Fired Water Heaters Installation and Operating Manual
Installation & Operating Manual
Do not place a valve between the combination temperature
and pressure relief valve and the tank.
Determine T&P relief valve size by the following
specifi cations, unless they confl ict with local codes:
- SST150-40 - 3/4” NPT with a minimum AGA Rating of
105,000 Btu/hr.
- SST250-65/300-80/450-119 - 3/4” NPT with a
minimum AGA Rating of 200,000 Btu/hr.
NOTICE:
 The SST series water heaters will absorb/
store less than 200,000 Btu/hr when
domestic water outlet temperature is 210°F
and boiler water supply temperature is
240°F. Listed outputs are based on ASME
Section VIII Interpretation VIII-1-86-136.
Check with local codes for applicability.
Minimum Relief Valve (AGA Rating) Table 4A
Model BTU/hr
SST150-40 105,000
SST250-65 200,000
SST300-80 200,000
SST450-119 200,000
Standard Installation
• Install the T&P relief valve in the connection marked
“Relief Valve”.
T&P Relief Valve Discharge Piping
T&P relief valve discharge piping must be:
- made of material serviceable for a temperature of
250°F or greater.
- directed so that hot water fl ows away from all persons.
- directed to a suitable place for disposal.
- installed so as to allow complete draining of the T&P
relief valve and discharge line.
- terminated within 6” of the fl oor.
T&P relief valve discharge piping must not be:
- excessively long. Using more than two (2) elbows or 15
feet of piping can reduce discharge capacity.
- directly connected to a drain. Refer to local codes.
- subject to freezing.
DANGER:
 Do not install any valve between the
temperatureand pressure (T&P) relief valve
and the tankconnection or on the T&P relief
valve discharge piping. Improper placement
and piping of T&P relief valve may result
in a discharge of hot water that can cause
severe personal injury, death or substantial
property damage.
WARNING:
 The temperature and pressure (T&P) relief
valve is not intended for constant duty,
such as relief of pressure due to repeated
normal system expansion. Correct this
condition by installing a properly sized
expansion tank in a domestic water system.
Refer to the expansion tank manufacturer’s
installation instructions for proper sizing.
Be advised, the hot discharge water from
the temperature and pressure (T&P) relief
valve, can cause severe personal injury, or
substantial property damage.
WARNING:
 Failure to install and maintain a new, listed
¾" X ¾" temperature and pressure (T&P)
relief valve will release the manufacturer
from any claim which might result from
excessive temperature and pressures or
discharge of hot water.