Detroit Radiant Products DST-60N, Руководство по установке, Страница: 29 / 52

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DST Series
Refer to Chart 3.3 for natural gas and Chart 3.4 for propane to determine the cubic feet per hour (CFH)
required for the type of gas and size of unit to be installed. To determine the proper pipe diameter, use the
CFH value and the length of pipe necessary from Chart 3.5. In the case where several units are serviced by
the same main gas line, the total capacity (CFH) and length of main must be adequate to service all
appliances downstream of this main.
Chart 3.3 • Natural Gas Consumption
3.0 Installation • Installation of the Gas Line to the Heater
Model
Input
High/Low
Manifold
Pressure
(Inches W.C.)
Min. Inlet
Pressure
(Inches W.C.)
Max. Inlet
Pressure
(Inches W.C.)
Gas
Consumption
(CFH)*
Gallons
p/ Hour
DST-60
60,000 (High) 10.0
11.0 14.0
24 .66
50,000 (Low) 7.1 20 .55
Model
Input
High/Low
Manifold
Pressure
(Inches W.C)
Min. Inlet
Pressure
(Inches W.C.)
Max. Inlet
Pressure
(Inches W.C.)
Gas Consumption
(CFH)*
DST-60
60,000 (High) 3.5
5.0 14.0
57.1
40,000 (Low) 1.5 38.1
DST-80
80,000 (High) 3.5
5.0 14.0
76.2
50,000 (Low) 1.5 38.1
Chart 3.4 • Propane Gas Consumption
* Assumes an average heating value of 1050 BTU/SCF and a Specific Gravity of 0.60.
* Assumes an average heating value of 2500 BTU/SCF and a Specific Gravity of 1.53.
Chart 3.5 allows for a 0.3 inch W.C. pressure drop in the supply pressure from the building main to the inlet
of the unit. Refer to the chart for the appropriate range of inlet pressures for each gas type. When sizing the
inlet gas pipe diameter, make sure that the unit supply pressure can be met after the 0.3 inch W.C. pressure
drop has been subtracted from the main pressure. If the 0.3 inch W.C. pressure drop is too high, refer to
NFPA 54 or the Gas Engineer’s Handbook for other gas pipe capacities.
Install ground joint union with a brass seat and a manual shut-off valve adjacent to the unit for emergency
shut-off and easy servicing of controls. A 1/8” NPT plugged tap that is accessible for a test gauge
connection is also recommended, as illustrated in Figure 3.14.
A sediment trap must be installed in the supply line in the lowest spot prior to connecting to the heater.
The trap length shall be at least three inches long. Ideally, the trap would be installed as close as possible
to the shut-off, as shown in Figure 3.14.