IBM 9835-415, Deployment Manual

Page: 71 / 126

Manifolds and piping
Manifolds that accept large-diameter feed pipes from a pump unit are the
preferred method for splitting the flow of water to smaller-diameter pipes or hoses
that are routed to individual heat exchangers. Manifolds must be constructed of
materials that are compatible with the pump unit and related piping (see “Water
specifications for the secondary cooling loop” on page 42). The manifolds must
provide enough connection points to allow a matching number of supply and
return lines to be attached, and the manifolds must match the capacity rating of
the pumps and the loop heat exchanger (between the secondary cooling loop and
the building chilled-water source). Anchor or restrain all manifolds to provide the
required support to avoid movement when quick-connect couplings are connected
to the manifolds.
Manifold supply pipe sizes
v Use a 50.8 mm (2 in.) supply pipe to provide the correct flow to six 19 mm (0.75
in.) supply hoses, with a 100 kW cooling distribution unit.
v Use a 63.5 mm (2.50 in.) supply pipe to provide the correct flow to eight 19 mm
(0.75 in.) supply hoses, with a 120 kW CDU.
v Use an 88.9 mm (3.50 in.) supply pipe to provide the correct flow to twenty 19
mm (0.75 in.) supply hoses, with a 300 kW CDU.
Use shutoff valves for each supply line that exits the manifold to enable the flow
of water to be stopped in individual legs of multiple-circuit loops. The shutoff
valves provide a way of servicing or replacing an individual heat exchanger
without affecting the operation of other heat exchangers in the loop.
Use adjustable flow control valves, called circuit setters, on each supply line to
enable control of the flow and compliance with specifications for each heat
exchanger.
Use temperature and flow metering (monitoring) in secondary loops to provide
assurance that water specifications are being met and that the optimum heat
removal is taking place.
Use circuit setters, placed as shown in Figure 20 on page 50 and Figure 21 on page
50, to enable the adjustment of water flow to each water circuit off a main
manifold system.
Anchor or restrain all manifolds and pipes to provide the required support and to
avoid movement when quick-connect couplings are being attached to the
manifolds.
Figure 20 on page 50 shows a layout for multiple water circuits.
Chapter 4. Physical installation site requirements
49