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PLUMBING CONNECTION
AUTUMN 2015
MANIFOLDING
T
he water heating principle of Rheem’s Equa-Flow®
plumbing is designed to ensure that all water heaters
in a bank are contributing an equal share of the
delivery performance and that there is equal flow from each
unit in the combined system.
The key principle of Equa-Flow is that the demand on each
water heater in the bank is the equal to any other. Adherence
to the following steps will lead to a good installation and
delivery performance from the system.
1. Sufficient space must be available to remove and replace
any water heater in the bank when necessary.
2. The cold water supply to the inlet of the manifold must
enter from the opposite end to that from which the
heated water line leaves the outlet of the manifold.
3. With mains pressure storage systems, the maximum
number of water heaters should be 8, however if the
demand of the application requires, several banks can be
installed in the Equa-Flow® design method.
4. The hot water header, cold water header and cold water
inlet pipe should be a minimum of DN32mm pipe and be
at least the next diameter above the size of pipe required
for the hot water outlet pipe to the building reticulation
system.
5. The outlet supply pipe delivering heated water
throughout the application needs to be sized to meet the
flow and demand requirements.
6. A non-return valve, isolation valve, and if necessary a
pressure limiting valve, must be installed on the main
cold water supply (refer diagram).
7. A full gate or ball valve must be installed on each
cold and hot branch connection lines into each water
heater to allow for shut down of each unit for service or
maintenance requirements but still maintaining heated
water delivery to the application via the remaining units
in the system.
8. Cold water supply branches to each water heater must
be identical. Hot water outlet branches from each water
heater must be identical.
9. Non return valves or loose jumper valves must not be
installed on the branch assemblies to each water heater,
since preferential flow through one water heater will
result.
IN MOST COMMERCIAL BUILDING APPLICATIONS WHERE LARGE VOLUMES OF HOT WATER ARE REQUIRED OVER
SHORT PERIODS AT CONSTANT HIGH TEMPERATURE TO MULTIPLE OUTLETS AT THE ONE TIME, TWO OR MORE
HEAVY DUTY WATER HEATERS CAN BE INSTALLED IN PARALLEL USING MANIFOLD PRINCIPLES.
JON PALFREY
EXPLAINS.
HOT WATER CLINIC
JON PALFREY
CORRECT TEMPERING VALVE INSTALLATION
POSITION ON A BRANCH ASSEMBLY
COLD WATER
SUPPLY
HOT WATER FLOW
HOT WATER FLOW
TO DRAIN
TO DRAIN
TO DRAIN
TO DRAIN
COLD WATER
SUPPLY
HOT WATER
RETURN
HOT WATER
RETURN