Install Instructions

Viega IM-MTL 0612
724607
51
17. SYSTEM DESIGN AND SIZING
17.1 System Design
ProPressG fittings and copper tubing
may be used in any fuel gas piping
systems where the quality of the fuel
gas has less than or equal to 0.3
grains of hydrogen sulfide per 100
standard cubic feet of gas (0.7
milligrams per 100 liters). Information
regarding fuel gas quality may be
obtained from the local gas supplier.
For natural gas, contact the local gas
utility. For liquid propane gas, contact
the liquid propane gas supplier.
Viega manufactures a full line of
ProPressG fittings ranging from 1/2" to
2". These fittings may be used in fuel
gas piping systems, including natural
gas and liquid propane gas while using
copper tubing.
Fuel gas piping systems are typically
very low pressure piping system. The
majority of fuel gas piping systems
inside a building have an operating
pressure of 0.5 psi or less. Codes
limit the maximum pressure of fuel
gas piping systems inside the
building to 5 psi or less.
Exceptions to this limitation are
special piping systems for research,
industrial processing, warehouses,
boiler and mechanical rooms.
The Viega ProPressG fitting system,
using copper tubing, is listed by CSA
LC-4 for fuel gas pressures up to 125
psi. ProPressG fittings can be used in
virtually every fuel gas piping system
inside the building.
ProPressG fittings may be installed
above and below ground, both inside
and outside of a building. Because
copper tubing is a corrosion resistant
material, copper tubing may be
installed underground with ProPressG
connections also installed underground.
Copper tubing may also be installed
underground from the source to the
building, meter, or regulator.
Using good engineering practices, a
ProPressG system can be designed
using the smallest allowable size of
tubing that will supply gas to the
appliance at the required volume and
pressure. For a single-family dwelling,
the gas company will frequently install
the meter outdoors and terminate its
facilities with a 1" NPS
(Nominal Pipe Size) threaded
connection outside the building.
The transition to copper tube can be
made at that point. Care should be
taken to ensure that the copper tube
is not used to support the meter. This
can be accomplished by anchoring the
meter to the exterior wall. Some gas
companies will set the meter with
a
Figure 17.1: Typical Branch Piping