Install Instructions

www.emersonclimate.com/flowcontrols
TFE Balanced-Port Thermal Expansion Valve
TFE Balanced-Port Thermal Expansion Valve
Instruction Sheet
PA-00270
June 2008
11911 Adie Road P.O. Box 411400 St. Louis MO 63141 USA CUSTOMER SERVICE [phone]
FEATURES
Emerson TFE Thermal Expansion Valves are designed to
meet the specific demands of refrigerated display cases,
reach-in and walk-in coolers and freezers, and commer-
cial applications ranging from medium (+50°F) to low
(-50°F) temperature, with proper charge.
• Bar-stock body - ODF connections
• External equalizer
• Corrosion-resistant materials
• Interchangeable with currently available commercial
refrigeration TXVs
• Field-replaceable power assembly
SAFETY INSTRUCTIONS
Warning: Before opening any system, make sure the
pressure in the system is brought to and remains at
atmospheric pressure. Use approved refrigerant recovery
methods when necessary. Failure to comply can result in
system damage and/or personal injury.
1. Read installation instructions thoroughly. Failure to
follow instructions may result in valve failure, system
damage, or personal injury.
2. Do not use on service conditions or fluids not
specifically cataloged, without prior written approval
of Emerson Climate Technologies Flow Controls
Division Applications Engineering Department. Use of
thermal expansion valves on applications not
specifically cataloged can result in valve failure and/
or system damage.
3. Warning: Do not place open flame on or near bulb.
4. Protect against excessive vibration, it may cause a
tubing break which will cause valve failure.
5. Do not exceed maximum working pressure of 450
psig, excess internal pressure could cause damage
to diaphragm, resulting in valve malfunction.
6. Do not exceed maximum working temperature (see
table 1) - excess temperatures could cause internal
damage, resulting in valve malfunction.
APPLICATION AND OPERATION
The TFE valve is currently replacing conventional
TXVs on air conditioning and refrigeration systems with
any combination of the following system operating
conditions:
1) Widely varying evaporator loads,
2) Widely varying head pressures,
3) Widely varying pressure drop available across the
thermostatic expansion valve and refrigerant distributor;
or,
4) Fluctuating or extremely low liquid temps.
Severe conditions are those which drastically
increase a conventional expansion valve's maximum
capacity: high head pressures for example, also, low
liquid temperatures that would be experienced on a
system with mechanical subcoolers during summer
operation. TFE high system performance is possible
because the large diaphragm allows the valve to operate
with the valve pin controlling very close to the seat. This
provides stable control at minimum changes in stroke,
enabling a large port to handle small loads. Compared to
a standard TXV, the TFE's larger port will improve system
pulldown.
Problems can occur with refrigeration systems during
both high and low ambient conditions when the condens-
ing temperature is allowed to follow the ambient. As the
evaporator temperature remains reasonably constant, this
results in extreme pressure drop changes across the
valve. These pressure drop changes can result in a
conventional valve not maintaining a constant superheat
at the evaporator outlet. These superheat changes can
result in the evaporator starving in low ambient conditions
and flooding in the higher ambient, depending on the
valve design. Another variable factor for this situation is
how low the head pressure is allowed to decrease. This of
course depends on whether heat reclaim is utilized for
heating purposes, or if hot gas will be used for evaporator
defrost.
TABLE 1
Maximum Dehydration Temperature °F
THERMOSTATIC CHARGE
REFRIGERANT C Z WMOP/CA
R134a 190 250 250
R22 160 185 250
R404A/507 150 170 250
This Table refers to the maximum dehydration
temperatures when the bulb and valve body are
subjected to the same temperature. On L, C, and Z
charges, 250°F maximum valve body temperature is
permissible (if the bulb temperature) does not
exceed those shown in the table.
NOMINAL CAPACITIES (IN TONS AT ARI CONDITIONS) *
Refrigerant R134a Refrigerant R22 Refrigerant R404A/507
+40°F evaporator temp. +40°F evaporator temp. +40°F evaporator temp.
60 psi pressure drop 100 psi pressure drop 100 psi pressure drop
86 5
10 8 7
12 10 9
20 15 14
* See Emerson Climate Technologies Flow Controls' Catalog for
extended capacities at other conditions.