Each unit must be installed with its own individual vent and means to flush or blow out the condensate drain line. Do not in- stall units with a common trap or vent.
1/4” Pitch for Drainage
Pitch Toward
Drain
Drain Connection
Fig. 10 — Horizontal Unit Pitch
NOTE: Trap should be deep enough to offset maximum unit static difference. A
Fig. 11 — Trap Condensate Drain
•Be sure to support the line where anticipated sagging from the condensate or when “double trapping” may occur.
•If condensate pump is present on unit, be sure drain connec- tions have a check valve to prevent back flow of condensate into other units.
Step 7 — Pipe Connections — Depending on the application, there are 3 types of WSHP piping systems to choose from: water loop,
All WSHP units use low temperature soldered female pipe thread fittings for water connections to prevent annealing and
•Use a backup wrench when making screw connections to unit to prevent internal damage to piping.
•Insulation may be required on piping to avoid condensation in the case where fluid in loop piping operates at tempera- tures below dew point of adjacent air.
•Piping systems that contain steel pipes or fittings may be subject to galvanic corrosion. Dielectric fittings may be used to isolate the steel parts of the system to avoid galvanic corrosion.
WATER LOOP APPLICATIONS — Water loop applications usually include a number of units plumbed to a common pip- ing system. Maintenance to any of these units can introduce air into the piping system. Therefore, air elimination equipment comprises a major portion of the mechanical room plumbing.
The flow rate is usually set between 2.25 and 3.5 gpm per ton of cooling capacity. For proper maintenance and servicing,
Cooling tower/boiler systems typically utilize a common loop maintained at 60 to 95 F. The use of a closed circuit evap- orative cooling tower with a secondary heat exchange between the tower and the water loop is recommended. If an open type cooling tower is used continuously, chemical treatment and fil- tering will be necessary.
In addition to complying with any applicable codes, consid- er the following for system piping:
3/4” Copper FPT/PVC
1/2”
Water
Connections
3/4” PVC Vent
1/4” per foot slope to drain
1/2”
Alternate
Condensate
Location
•Piping systems using water temperatures below 50 F require
•Avoid all plastic to metal threaded fittings due to the poten- tial to leak. Use a flange fitted substitute.
•Teflon tape thread sealant is recommended to minimize internal fouling of the heat exchanger.
•Use backup wrench. Do not overtighten connections.
•Route piping to avoid service access areas to unit.
•Flush the piping system prior to operation to remove dirt and foreign materials from the system.
NOTE: Unit does not need to be sloped toward drain.
Fig. 12 — Vertical Condensate Connection
VENTING — Install a vent in the condensate line of any application that may allow dirt or air to collect in the line. Con- sider the following:
•Always install a vent where an application requires a long horizontal run.
•Always install a vent where large units are working against higher external static pressure and to allow proper drainage for multiple units connected to the same condensate main.
•Install
•Install
•Connect boiler drains and other valves using a “T” connec- tor to allow acid flushing for the heat exchanger.
•Do not overtighten connections.
•Route piping to avoid service access areas to unit.
•Use PVC SCH80 or copper piping material.
NOTE: PVC SCH40 should not be used due to system high pressure and temperature extremes.
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