Weil-McLain GV90+ - Manual (Page 28)

Part number 550-142-054/0411
GV90+
gas
-
fired water boiler
— Boiler Manual
28
Multiple boiler water piping
(continued)
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) —
layout and size per page 24
5 Easy-Fit® Manifold (return) — lay-
out and size per page 24
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 Fig-
ure 32, page 25 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 contami-
nated with scale and rust buildup
inside piping and heat distribu-
tion units.
4. Process applications.
5. Commercial service water ap-
plications.
6. High water pressure applications,
requiring pressure relief setting
in heating system more than 50
PSIG (tall buildings). See notes
below.