22
Mexico Super FF4100 & FF4125 -
Installation & Servicing
INSTALLATION
Notes.
a.
Flow and return pipes should rise vertically on leaving the
boiler.
b.
Horizontal pipes should be ABOVE ceiling level and as short
as possible.
c.
A MINIMUM inclination of 25 mm per 3 m run (1" per 10') is
required to avoid air locks.
If the above conditions cannot be met pumped primaries should
be used.
1.
Separate flow and return connections are used for each
service. All possible configurations are given in Frame 8 and
ONLY those shown should be used.
2.
The schematic pipework graph is based on the assumption
that NO MORE than 8 elbows are used in the gravity loop,
including entry to the boiler.
3.
For each extra elbow in excess of 8 (R) MUST be reduced by
300 mm (12") or (H) increased by 100 mm (4")
4.
Whatever value is selected for (R), the value of (H) MUST be
at least that indicated by the graph.
(R)
=
the horizontal distance between the centre line of the
cylinder and the boiler tappings used - measured along
the pipe run.
(H)
=
the vertical distance between the top of the boiler and
the base of the cylinder.
41 MINIMUM REQUIREMENTS
Fully pumped systems
1.
Open vent and cold feed connections must be made to the boiler
flow and return tappings according to the options shown in Frame
8.
2.
The boiler is assumed to be the highest point of the
circulating system.
3.
The circulating pump is positioned on the FLOW and
the vertical distance, between the pump and feed/
expansion tank, must comply with the pump
manufacturer's minimum requirements, to avoid
cavitation. Should these conditions not apply, either
lower the pump position or raise the feed/ expansion
tank above the minimum requirements of
Caradon
Ideal Ltd.
4.
The water velocity through the boiler flow / return pipes
is assumed to be below 1 m/s (3 ft./s), whilst the pump
flow rate is set to provide a temperature difference of
11
o
C (20
o
F) across the boiler flow / return, at design
input.
5.
This information is intended as a GUlDE ONLY and
cannot take into account instantaneous changes in
head caused by the operation of motorised valves,
pumps etc.
Due allowance MUST be made if surging is liable to
occur.
If in any doubt, contact
Caradon Ideal Ltd.
42 GRAVITY HOT WATER & PUMPED CENTRAL HEATING
INST
ALLA
TION
200940-1.p65
3/2/2004, 9:06 AM
22
