17
Recommended Piping
All piping must be properly and adequately supported at coupling connections and suitable intervals along the piping runs. Hanger design must
provide for the weight of fluids in the piping system when the chiller is in operation.
Multistack modules are equipped with brazed plate heat exchangers made of 316 stainless steel. Multistack recommends use of a 30-mesh system
strainer, Y-type basket or equal, in each condenser and evaporator inlet header.
It is the installing contractor’s responsibility to make sure the water systems have been flushed and the strainers are clean and clear of debris before
starting the chiller. Do not flush piping so as to push debris into or through the through the chiller heat exchangers.
Typical Sensor Wells
Important
Be sure to install the supplied sensor wells in the system piping. The wells should be installed
a few feet from the chiller in the entering and leaving chilled water and entering and leaving
condenser water pipes.
Flow Protection
Proof of chilled water and condenser water flow is required by the Master Controller inputs. Paddle-type or Differential Pressure (DP) switches may
be used. Switches can be supplied by Multistack as an option, otherwise they are to be field supplied and installed. Chillers purchased with chilled
or condenser water pump modules have a DP switch installed across the pump to verify operation. Multistack recommends a paddle-type switch be
installed in the leaving chilled water piping using a differential pressure switch. Install it across the inlet and outlet water connections to the chilled
and/or condenser water piping connections.
System Water Volume
A properly sized chilled water system must have enough time (at least three minutes) to properly control and respond to changes in load and to
prevent short cycling of the chiller. To ensure the system water volume is adequate, a general rule of thumb is:
7-10 gallons of water per ton or Acceptable Chilled Water Volume = Chilled Water Design GPM X 3
If the system heat exchangers, piping and components cannot hold the necessary chilled water volume, a properly sized chilled water storage tank
should be added.
Condenser Water Temperature Control
For installations where entering condenser water temperature could be lower than 65°F Multistack recommends installing a three-way tower bypass
valve to maintain a minimum of 65°F entering condenser water temperature. This is based on a 10°F Delta-T system.
CONDENSER SIDE
EVAPORATOR SIDE
Items in This Area Included
with Chiller
To Cooling Tower
or Fluid Cooler
Flow/DP
Switch
Isolation
Valves
Sensor Pockets, Sensors
Supplied by Multistack,
installed by others.
Pressure
Taps
Pressure
Taps
Sensor Pockets, Sensors
Supplied by Multistack,
installed by others.
Isolation
Valves
Flow/DP
Switch
Strainer
Condenser
Pump
3-Way
Bypass Valve
CW In
CW Out
Strainer
Chilled Water
Pump
CHW In
CHW Out
Pressure
Taps
