Step 7 - Pipe Connections; Water Loop Applications; Ground Loop Applications; Installing Supply And Return Hose Kit - Carrier Aquazone 50PCH Installation, Start-Up And Service Instructions Manual

Step 7 — Pipe Connections —
application, there are 3 types of WSHP piping systems to
choose from: water loop, ground-water and ground loop. Refer
to Piping Section of Carrier System Design Manual for addi-
tional information.
All WSHP units use low temperature soldered female pipe
thread fittings for water connections to prevent annealing and
out-of-round leak problems which are typically associated with
high temperature brazed connections. Refer to Tables 1 and 2
for connection sizes. When making piping connections, con-
sider the following:
• Use a backup wrench when making screw connections to
unit to prevent internal damage to piping.
• Insulation may be required on piping to avoid condensa-
tion in the case where fluid in loop piping operates at
temperatures 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 gpm per ton
of cooling capacity. For proper maintenance and servicing,
pressure-temperature (P/T) ports are necessary for temperature
and flow verification.
In addition to complying with any applicable codes, consid-
er the following for system piping:
• Piping systems using water temperatures below 50°F
require 1 / -in. closed cell insulation on all piping surfaces
2
to eliminate condensation.
• Avoid all plastic to metal threaded fittings due to the
potential 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.
GROUND LOOP APPLICATIONS — Temperatures be-
tween 25 and 110°F and a cooling capacity of 2.25 to 3 gpm of
flow per ton are recommended. In addition to complying with
any applicable codes, consider the following for system piping:
• Limit piping materials to only polyethylene fusion in the
buried sections of the loop.
• Do not use galvanized or steel fittings at any time due to
corrosion.
• Avoid all plastic to metal threaded fittings due to the poten-
tial to leak. Use a flange fitted substitute.
• Do not overtighten connections.
• Route piping to avoid service access areas to unit.
• Use pressure-temperature (P/T) plugs to measure flow of
pressure drop.
INSTALLING SUPPLY AND RETURN HOSE KIT —
Follow these piping guidelines:
1. Install a drain valve at the base of each supply and return
riser to facilitate system flushing.
2. Install shutoff/balancing valves and unions at each unit to
permit unit removal for servicing.
3. Place strainers at the inlet of each system circulating
pump.
4. Select the proper hose length to allow slack between con-
nection points. Hoses may vary in length by +2% to –4%
under pressure.
Depending on the
11
5. Do not exceed the minimum bend radius for the hose se-
lected. Refer to Table 5. Exceeding the minimum bend ra-
dius may cause the hose to collapse, which reduces water
flow rate. Install an angle adapter to avoid sharp bends
in the hose when the radius falls below the required
minimum.
NOTE: Piping must comply with all applicable codes.
Table 5 — Metal Hose Minimum Bend Radii
HOSE DIAMETER (in.)
1
/
2
3
/
4
1
Insulation is not required on loop water piping except where
the piping runs through unheated areas or outside the building
or when the loop water temperature is below the minimum ex-
pected dew point of the pipe ambient. Insulation is required if
loop water temperature drops below the dew point.
IMPORTANT: Do not bend or kink supply lines or hoses.
Pipe joint compound is not necessary when Teflon* thread-
ed tape is pre-applied to hose assemblies or when flared-end
connections are used. If pipe joint compound is preferred, use
compound only in small amounts on the male pipe threads of
the fitting adapters. Prevent sealant from reaching the flared
surfaces of the joint.
NOTE: When anti-freeze is used in the loop, assure that it is
compatible with Teflon tape or pipe joint compound employed.
Maximum allowable torque for brass fittings is 30 ft-lb. If a
torque wrench is not available, tighten finger-tight plus one
quarter turn. Tighten steel fittings as necessary.
Optional pressure-rated hose assemblies designed specifi-
cally for use with Carrier units are available. Similar hoses can
be obtained from alternate suppliers. Supply and return hoses
are fitted with swivel-joint fittings at one end to prevent kink-
ing during installation.
CAUTION
Backup wrench is required when tightening water connec-
tions to prevent water line damage. Failure to use a backup
wrench could result in equipment damage.
Male adapters secure hose assemblies to the unit and risers.
Install hose assemblies properly and check them regularly to
avoid system failure and reduced service life. See Fig. 11.
RIB
CRIMPED
LENGTH
(2 ft LENGTH STANDARD)
Fig. 11 — Supply/Return Hose Kit
* Registered trademark of DuPont.
MINIMUM BEND RADII (in.)
1
2 /
2
4
1
5 /
2
SWIVEL
BRASS
BRASS
FITTING
FITTING
MPT