RT-SVX36G-EN
63
Installation
7.
Install the 3-way valve in an upright position, piped for valve seating against the flow. Ensure
that the valve's location lends itself to serviceability.
8. The Type “W” hot water coil used in SLHL units is self-venting only when the tube water velocity
exceeds 1.5 feet per second (fps). If the tube velocity is less than 1.5 feet per second, either:
a. install an automatic air vent at the top of the return header, using the tapped pipe
connection;
or,
b. vent the coil from the top of the return header down to the return piping. At the vent
connection, size the return piping to provide sufficient water velocity.
9. Install a “Globe” type valve in the Bypass line as shown in
and
Steam Heat Units (SSH_)
Steam heating coils are factory installed inside the heater section of the unit. The coils are pitched,
within the units, to provide the proper condensate flow from the coil. To maintain the designed
degree of pitch for the coil, the unit must be level.
Once the unit is set into place, the steam piping and the factory provided two way modulating valve
must be installed. The valve can be installed inside the heater section or near the unit. If the valve
is installed in a remote location, use field supplied wiring to extend the control wires from the
heater section to the valve. Two access holes are provided in the unit base as illustrated in
.
Following the guidelines listed below will enhance both the installation and operation of the “wet
heat” system.
illustrate the recommended piping configurations for the steam coil.
lists the coil connection sizes.
Note:
The valve actuators are not waterproof. Failure to protect the valve from moisture may
result in the loss of heating control.
1.
Support all field-installed piping independently from the heating coil.
2. Use swing joints or flexible connectors adjacent to the heating coil. (These devices will absorb
the strains of expansion and contraction.)
3. Install the 2-way valve in an upright position. Ensure that the valve's location lends itself to
serviceability.
4. Pitch the supply and return steam piping downward 1" per 10' of run in the direction of flow.
5. All return lines and fittings must be equal to the diameter of the “outlet” connection on the
steam coil(s). If the steam trap connection is smaller that the coil “outlet” diameter, reduce the
pipe size between the strainer and the steam trap connections only.
Table 20. Connection Sizes for Hot Water and Steam Coil
(a)
(a) Type W coils—with center offset headers—are used in SLH_ units; Type NS coils are
used in SSH_ units.
Coil Connections
(diameter in inches)
Unit Model and Size
Heat Section
Capacity
(b)
(b) See Digit 9 of the unit model number to determine the heating capacity.
Supply
Return
SLH*-20 to 130
High or Low Heat
2-1/2"
2-1/2"
SSHL-20 to 36
High or Low Heat
3"
1-1/4"
SSHL-40 to 89
(c)
(c) SSH_ - 40 to 89 Ton units have multiple headers.
High Heat Low Heat
3"
1-1/2"
SSHK-90 to 130
Low Heat
(c)
1-1/2”
1”
