State GPO 69 700OE - Manual (Page 7)

7
WATER PIPING
GENERAL
Select the piping diagram for the type of system to be installed from pages
14 through 18. When a circulation pump is used in the system a plug
cock should be installed where indicated to regulate water flow through
the heater.
RELIEF VALVE
An CSA design-certified and A.S.M.E.-rated temperature and pressure
relief valve is installed in the water heater . The relief valve has a discharge
capacity exceeding the maximum heater input rating and a pressure rating
not exceeding the working pressure shown on the rating plate of the heater.
A temperature and pressure relief valve must also be installed on any potable
water storage tank. This relief valve should have a temperature rating of
210° F (98.9°C), a pressure rating not exceeding the lowest rated working
pressure of any system component, and a discharge capacity exceeding
the total input of the water heaters supplying water to the storage tank.
THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE, WHICH
MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM
OR HEATER DAMAGE.
To avoid scalding or water damage, a drain line must be connected to a
relief valve to direct discharge to a safe location, A DRAIN LINE MUST
NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND
IT MUST NOT CONTAIN ANY VALVES BETWEEN THE HEATER AND
THE RELIEF VALVE OR THE RELIEF VALVE AND THE DRAIN LINE
EXIT. IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS
IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH AREAS
WHERE FREEZING CONDITIONS MIGHT OCCUR. DO NOT THREAD
OR CAP THE DRAIN LINE EXIT. RESTRICTING OR BLOCKING A DRAIN
LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY
CREATE AN UNSAFE CONDITION. Install a drain line with a downward
slope such that it naturally drains itself.
Your local code authority may have other specific relief valve requirements.
NOTE: These heaters are equipped with an automatic burner shutoff
system actuated by high water temperature.
CLOSED WATER SYSTEM
A closed system will exist if a back-flow preventer (check valve), pressure
reducing valve, or other similar device is installed in the cold water line
between the water heater and the street main (or well). Excessive pressure
may develop due to the thermal expansion of heated water causing
premature tank failure or intermittent relief valve operation. This type of
failure is not covered by the limited warranty. An expansion tank may be
necessary in the cold water supply to alleviate this situation, see installation
diagrams on pages 14-18. Contact the local plumbing authority.
DRAIN VALVE AND ACCESS PANELS
The heaters are equipped with a 3/4" NPT drain valve mounted above and
to the left of the oil burner, see FEATURES, page 2.
An access panel is located above and to the left of the oil burner and
covers the flame observation port, fig. 7. A plug is inserted into the flame
observation port and must be removed in order to look into the combustion
chamber. Always reinstall plug before replacing access panel.
COMBUSTION CHAMBER ACCESS PORT - FIGURE 7.
Another access panel is located above and to the right of the oil burner,
fig. 8. This panel covers the cleanout opening in the tank which is sealed
by a gasket and cover.
TANK CLEANOUT PORT - FIGURE 8.
Models having ASME tank construction will have two cleanout ports. One port
will be located as indicated above and the other will be located directly opposite.
Occasionally, some water seepage will occur at a cleanout port. To correct
this situation, slightly tighten the cleanout cover bolts until the seepage
is eliminated. Do not over tighten the bolts or the cleanout gasket will be
damaged. Tighten each bolt gradually and alternate between opposed
bolts on the cleanout cover.
FUEL SYSTEMS
GENERAL
The Standard for the Installation of Oil Burning Equipment-NFPA No. 31,
local codes, and these instructions must be followed when installing the
tank, piping and burner. In addition, an oil pump installation sheet and oil
burner certificate are packed with the burner for use and completion by
the installer.
On fuel systems with high pressures, a Webster "OSV" oil safety valve
(Webster Electric CO., Racine, Wisc.) will be required to reduce the oil
pressure at the burner pump. See FUEL PUMP, page 9, for pressure
ratings of the burner's pump.
This manual and the completed oil burner certificate (CS75) are to be left
with the user for future reference.
Figure 9 shows a typical single stage one or two line fuel system. When
two or more tanks are connected to one burner, the supply line from each
tank should run to a header fitted with an approved three-way valve.
Normally only one tank may be drawn at a time unless local codes permit
simultaneous feeding of two tanks on gravity type installations.
A TYPICAL HEATER INSTALLATION - FIGURE 9.
Refer to pages 2, 3, and 4 in this manual for more information about burner
series numbers and characteristics for adaptability to the following systems.
SYSTEM TYPES
Single Stage, Supply Line Only: The bottom of the oil storage tank must
be above the level of the fuel unit, fig. 10. The fuel oil will flow by gravity to
the burner. A single pipe joins the tank and fuel unit. Burner Series No. 940
is from this type of service as shipped (the bypass plug is not installed).