Lochinvar EFFICIENCY PLUS, Руководство дизайнера

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14 L o c h i n v a r
D E S I G N E R
’
S G U I D E E F F I C I E N C Y
+
B O I L E R
6 1 5 - 8 8 9 - 8 9 0 0
GAS SUPPLY
Safe operation of unit requires properly
sized gas supply piping (See TABLE G).
Gas pipe size may be larger than the
heater connection.
An internal gas pressure regulator is required
if upstream pressure exceeds 6 oz. (10.5"
water column), an intermediate gas
pressure regulator, of the lockup type,
must be installed.
Installation of a union is suggested for
ease of service.
Install a manual main gas shutoff valve
with test plug, outside of the appliance
gas connection and before the gas valve,
when local codes require.
A trap (drip leg) should be provided in the
inlet of the gas connection to the unit.
High Altitude Applications
Atmospheric pressure decreases as the height
above sea level increases. At any altitude
above sea level, a cubic foot will contain less
gas than a cubic foot at sea level. Thus, the
heating value of a cubic foot of fuel gas will
decrease as height above sea level increases.
Specific gravity of a gas with respect to sea
level also decreases with altitude.
These changes in heating value and specific
gravity tend to offset each other. However, as
elevation above sea level is increased, there
is less oxygen per cubic foot of air. Therefore,
heat input rate should be reduced in an
appliance above 2000 feet. Ratings should
be reduced at the rate of 4 percent for each
1000 feet above sea level.
WATER CONNECTIONS
Inlet and Outlet Water Connections
For ease of service, install unions on inlet and
outlet of the boiler. The connection on the unit
marked “Inlet” should be used for return
water from the system. The connection on the
header marked “Outlet” should be connected
to the system supply. (See Boiler Piping
diagrams, Appendix A).
Lochinvar
NOTE:
Care should be
taken to measure
temperature rise
and maintain proper
water velocity in
the heat exchanger.
(TABLE H) – INLET GAS PRESSURE REQUIREMENTS
NATURAL GAS LPG
Max. Allowable 10.5” 13”
(Inches-water column)
Min. Allowable 4.7” 8”
(Inches-water column)
EXAMPLE OF
HIGH
ALTITUDE
APPLICATIONS
For example, if a unit’s
input is 200,000 Btu/hr
at sea level, the rated
input at 4000 feet of
elevation can be calculated
by derating input 4%
per 1000 feet above
sea level.
[Btu/hr Input]
[1.00 - (Elevation/ 1000’
x 0.04)] = Btu/hr Input
at specified elevation.
[200,000][1.00 -
(4000’/1000’ x 0.04)] =
Btu/hr Input 4000’
elevation.
[200,000][0.84] =
168,000 Btu/hr Input
at 4000’ elevation.
(TABLE G) – GAS SUPPLY PIPE SIZING
Length of Pipe In Straight Feet
Nominal Iron
Pipe Size, Inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200
Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and a total
system pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).
3/4 369 256 205 174 155 141 128 121 113 106 95 86 79 74
1 697 477 384 328 292 267 246 256 210 200 179 164 149 138
1-1/4 1,400 974 789 677 595 543 502 472 441 410 369 333 308 287
1-1/2 2,150 1,500 1,210 1,020 923 830 769 707 666 636 564 513 472 441
2 4,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820
2-1/2 6,460 4,460 3,610 3,100 2,720 2,460 2,310 2,100 2,000 1,900 1,700 1,540 1,400 1,300
3 11,200 7,900 6,400 5,400 4,870 4,410 4,000 3,800 3,540 3,300 3,000 2,720 2,500 2,340
4 23,500 16,100 13,100 11,100 10,000 9,000 8,300 7,690 7,380 6,870 6,150 5,640 5,130 4,720
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