Part number 550-143-010/1021
28
GV90+
series
2
gas-fired water boiler – boiler manual
Figure 35
Piping layout — typical for multiple GV90+ boilers, using isolation exchanger
Legend — Figure 35
1 Flow/check valve (each boiler)
2 Isolation valves (when used)
3 Cap
4 Easy-Fit® Manifold (supply) — lay-
out and size per
5 Easy-Fit® Manifold (return) — lay-
out and size per
6a Heating system circulator (exchang-
er tube-side)
6b Heat exchanger shell-side circulator
7 Expansion tanks (diaphragm type)
8 System air eliminator
9 System automatic air vent
13 Cold water supply connections
16 Cold water fill line — see
for typical compo-
nents
18 Heating system supply
19 Heating system return
20 Boiler relief valve and discharge
piping, installed per GV90+ Boiler
Manual
30 Sensor for BCP (boiler control
panel), when used
Notes:
1. Contact heat exchanger manufacturer for heat ex-
changer shell-side and tube-side piping and circulator
requirements. Tube-side flow and temperatures must
meet heating system requirements.
2. Contact heat exchanger manufacturer for sizing heat
exchanger.
3. Heat exchanger shell-side circuit requires its own
expansion tank as shown.
4. Heating system circuit requires its own expansion tank,
as shown, plus its own relief valve set to protect heating
system and heat exchanger piping and components.
5. When individual isolation valves are used, individual
boiler and level controls may be required.
Use isolation heat
exchanger for:
1. Large volume systems with high
mineral content in water.
2. Systems exposed to untreated
quantities of makeup water.
3. Old systems severely con-
taminated with scale and rust
buildup inside piping and heat
distribution units.
4. Process applications.
5. Commercial service water ap-
plications.
6. High water pressure applica-
tions, requiring pressure relief
setting in heating system more
than 50 PSIG (tall buildings).
See notes below.
Multiple boiler water piping
(continued)
