Gas Connection And Piping; Gas Piping Pressure Test - Viessmann Vitocrossal 300 CU3A 26 Installation Instructions Manual

Vitocrossal 300 CU3A 26 to 199 Installation
Connections
(continued)
Legend
¾
A Gas connection 7
B Accessible manual gas shutoff valve (supplied)
C Ground joint union
D Drip leg

Gas connection and piping

1. Refer to current CAN/CSA B149.1 and .2 or National
Fuel Gas Code ANSI Z223.1/NFPA 54, as well as
local codes for gas piping requirements and sizing.
Pipe size to the boiler must be determined based on:
- pipe length
- number of fittings
- type of gas
- maximum input requirements of all gas appliances
in the residence.
IMPORTANT
Design piping layout in such a way that piping does not
interfere with serviceable components.
2. Before connecting boiler to gas line, install ground
joint union, capped drip leg and a manual equipment
shutoff valve as shown. Valves must be listed by a
nationally recognized testing agency. Make boiler gas
connection as shown.
3. Perform gas piping pressure test as described in the
following subsection.
IMPORTANT
Max. gas supply pressure: 14 "w.c.
4. Identify shutoff valves as such with a tab and
familiarize operator / ultimate owner of boiler with
these valves.
in. (NPT)
See Vitocrossal 300, CU3A Service Instructions
for applicable system coding changes.
WARNING
The gas supply piping must be leak tested before placing
the boiler in operation.
CAUTION
Ensure that gas piping is large enough for all appliances in
the residence. No noticeable gas pressure drop in the gas
line must occur when any unit (or combination of units)
lights or runs.

Gas piping pressure test

When performing the gas piping pressure test, ensure the
following requirements are met.
WARNING
Never check for gas leaks with an open flame.
WARNING
Exposing boiler gas pressure regulator and gas valve to
extreme pressures renders warranty null and void.
IMPORTANT
½ psig = 14 "w.c.
1. Isolate the boiler from the gas supply piping system
using the individual manual shutoff valve during
pressure tests equal to or less than ½ psig (14 "w.c.)
2. The boiler and its individual shutoff valve must be
disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of ½ psig (14 "w.c.)
3. Perform leak test.
Use approved liquid spray solution for bubble test.
Ensure that no liquid is sprayed on any electrical
components, wires or connectors. Do not allow
leak detection fluid to contact gas valve regulator
or regulator vent opening.
4. Correct any and all deficiencies.
5. Remove air from gas line.
Boiler Connections
15