26
3
Gas connections
Installation & Service Manual
Gas connection
1. Safe operation of appliance requires properly sized gas
supply piping. See data below.
2. Gas pipe size may be larger than heater connection.
3. Installation of a union is suggested for ease of service.
4. Install a manual main gas shutoff valve, outside of the
appliance gas connection and before the gas valve, when
local codes require.
5. A trap (drip leg) MUST be provided in the inlet of the
gas connection to the appliance.
6. The combination gas valve has an integral vent limiting
device and does not require venting to atmosphere,
outside the building. The appliance will not operate
properly if the reference hose is removed or a vent to
atmosphere is installed.
7. Optional gas controls may require routing of bleeds and
vents to the atmosphere, outside the building when
required by local codes.
8. Inlet gas connections to the gas valve is 3/4" NPT for the
150,000 through 300,000 Btu/hr models.
For each elbow or tee, add equivalent straight pipe to total
length from table below.
TABLE 3E
90
°
FITTINGS TO EQUIVALENT
STRAIGHT PIPE
Diameter Pipe (Inches)
3/4"
1"
1 1/4"
1 1/2"
2"
3"
4"
5"
Equivalent Length of Straight Pipe (Feet)
2"
2 1/2"
3 1/2"
4"
5"
10"
14"
20"
Gas piping
Figure 3-1 Gas Piping to Heater
All gas connections must be made with pipe joint
compound resistant to the action of liquefied petroleum
and natural gases. All piping must comply with local codes
and ordinances. Tubing installations must comply with
approved standards and practices.
Install Piping to Control
1. The gas line should be a separate line direct from the
meter unless the existing gas line is of sufficient
capacity. Verify pipe size with your gas supplier.
2. Use new, properly threaded black iron pipe free from
chips. If tubing is used, make sure the ends are square,
deburred and clean. All tubing bends must be smooth
and without deformation. Avoid flexible gas connections.
3. Run pipe or tubing to the control. If tubing is used,
obtain a tube to pipe coupling to connect the tubing to
the
control.
4. Install a sediment trap in the supply line to the gas
control.
5. Thread pipe the proper amount for insertion into
gas valve. Effective length of standard 3/4" NPT
thread is 9/16", overall length of thread is 3/4".
DO
NOT THREAD PIPE TOO FAR
. Valve distortion or
malfunction may result if the pipe is inserted too deeply.
6. Apply a moderate amount of good quality pipe
compound
(
DO NOT
use Teflon tape) to pipe only,
leaving two end threads bare).
Summary of Contents for Efficiency-Pac EW 150 -- 300
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