Design Dynamics VTD-18N-PDG - Manual (Page 9)

www.desatech.com 111826-02J 9
CAUTION: Make sure exter-
nal regulator has been installed
between propane/LP supply
and heater. See guidelines un-
der Connecting to Gas Supply,
page 7.
PRESSURE TESTING GAS SUPPLY
PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance main
gas valve (control valve) and equipment
shutoff valve from gas supply piping system.
Pressures in excess of 1/2 psig will damage
heater regulator.
2. Cap off open end of gas pipe where equipment
shutoff valve was connected.
3. Pressurize supply piping system by either
opening propane/LP supply tank valve for
propane/LP gas or opening main gas valve
located on or near gas meter for natural gas
or using compressed air.
4. Check all joints of gas supply piping system.
Apply noncorrosive leak detection fluid to all
joints. Bubbles forming show a leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment shutoff
valve to gas supply. Check reconnected fit-
tings for leaks.
Test Pressures Equal To or Less Than
1/2 PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Figure 8).
2. Pressurize supply piping system by either
opening propane/LP supply tank valve for
propane/LP gas or opening main gas valve
located on or near gas meter for natural gas
or using compressed air.
INStALLAtION
Continued
Check your building codes for any special re-
quirements for locating equipment shutoff valve
to fireplaces.
Apply pipe joint sealant lightly to male NPT
threads. This will prevent excess sealant from
going into pipe. Excess sealant in pipe could result
in clogged heater valves.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
We recommend that you install a sediment trap in
supply line as shown in Figure 7, page 8. Locate
sediment trap where it is within reach for clean-
ing. Install in piping system between fuel supply
and heater. Locate sediment trap where trapped
matter is not likely to freeze. A sediment trap
traps moisture and contaminants. This keeps them
from going into heater controls. If sediment trap
is not installed or is installed wrong, heater may
not run properly.
CAUTION: Avoid damage to
gas control. Hold gas control
with wrench when connecting it
to gas piping and/or fittings.
CHECkING GAS CONNECTIONS
WARNING: Test all gas piping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open flame to check for a leak.
Apply a noncorrosive leak detec-
tion fluid to all joints. Bubbles
forming show a leak. Correct all
leaks at once. Figure 8 - Equipment Shutoff Valve
Open
Closed
Equipment
Shutoff Valve