User Guide

Table 2 lists some of the major HFC and HCFC replacement
refrigerants for R-11, R-12, R-114, and R-502.
Sporlan Selective Charges
Sporlan introduced Selective Charges for TEVs over 50
years ago, recognizing that a single thermostatic charge
cannot work effectively over the useful range of evaporat-
ing temperatures of many standard refrigerants. The pres-
ent universal acceptance of Selective Charges is evidence
of their many operational advantages. An explanation of
their applications, design features, and advantages of each
Selective Charge follows. Recommended Sporlan thermo-
static charges for various applications are listed on Page 18.
The thermostatic expansion valve’s static superheat ver-
sus evaporator temperature is referred to as the superheat
characteristic curve. This curve is helpful in understand-
ing TEV operation since its shape describes the valve’s
operation at a given setting over a range of evaporating
temperatures. Figure 6 illustrates the superheat character-
istic curves of standard Sporlan thermostatic charges. The
concept of static superheat is described on Page 14, Factors
Affecting TEV Operation and Performance.
Air Conditioning and Heat Pump Applications
These applications usually require a pressure limiting
(MOP type) thermostatic charge to limit compressor load-
ing during system pulldown. The pressure limiting charge
causes the TEV to open only slightly until the system evapo-
rator pressure is reduced below the MOP of the charge,
permitting rapid pulldown.
The Sporlan thermostatic charges listed on Page 18 under
the air conditioning and heat pump section are gas-cross
charges.
Figure 6 illustrates the superheat characteristic curves of
the Sporlan VCP100 and VG charges, a gas-cross charge and
a gas charge respectively for R-22 applications. The VCP100
charge has a flatter operating range which allows the TEV to
maintain a more constant superheat with changes in evapo-
rating temperature. This characteristic is generally desired
since many air conditioning and heat pump systems operate
over a significant range of evaporating temperatures. The
VG charge has limited application except for our WVE-180
valve. The vertical portion of the curves is the MOP region
of both charges.
Sporlan pressure limiting charges also help reduce the
problem of the TEV alternately overfeeding and underfeed-
BULLETIN 10-9 / Page 7
the TEV is in its normal operating range. This characteristic
provides an MOP for the valve at the bulb temperature at
which the liquid component of the charge becomes vapor.
Above this bulb temperature, a temperature increase does
not significantly increase thermostatic charge pressure, lim-
iting the maximum evaporator pressure at which the system
can operate. A disadvantage of this type of thermostatic
charge is the possibility of charge migration.
The adsorption charge consists of a noncondensable gas and
an adsorbent material located in the sensing bulb. As the
temperature of the bulb increases, gas is expelled (desorbed)
from the adsorbent material increasing bulb pressure.
Conversely, as the temperature of the bulb decreases, gas is
adsorbed thus decreasing bulb pressure. Like the liquid and
liquid-cross charges, the adsorption charge does not provide
an MOP, and it will not migrate.
SPORLAN THERMOSTATIC EXPANSION VALVES
Sporlan manufactures thermostatic expansion valves for all
air conditioning and refrigeration applications. For applica-
tions using refrigerants R-12, R-22, R-134a, R-404A, R-502,
and R-507, Sporlan’s standard line of TEVs are available
with SAE flare, ODF solder, ODF solder flange, and FPT
flange connections. Specifications for the TEVs are provided
in Bulletin 10-10. Materials and details of construction are
also provided in Bulletin 10-10.
For refrigerant R-717 (ammonia) applications, TEVs are
available with FPT and socket weld flange connections.
These valves are manufactured and marketed through
Parker Refrigerating Specialties (R/S) Division.
Valve capacity ratings for refrigerants R-12, R-22, R-134a,
R-401A, R-402A, R-404A, R-407A, R-407C, R-408A, R-409A,
R-502, R-507, and R-717 are listed in Bulletin 10-10. The
capacity tables on these pages specify valve ratings at
selected evaporator temperatures. Contact Sporlan for appli-
cations not specifically listed in Bulletin 10-10.
In addition to the standard line of TEVs listed in this bul-
letin, Sporlan also manufactures special valve types to fill
specific requirements for OEM customers. These OEM valve
types include the Type BI, I, FB, and X TEVs. Special fea-
tures such as bleed ports, nonadjustable construction, and
extra length capillary tubing are available for many stan-
dard and OEM valves. Automatic expansion valves are also
available on special order. If you have a special refrigerant
flow control application, contact Sporlan for assistance.
Alternative Refrigerants
Sporlan has an ongoing program to evaluate alternative refrig-
erants and, when applicable, their associated refrigerant lubri-
cants to assess compatibility with our materials of construction.
For additional information on this subject, contact Sporlan.
CFC )CFCH(sevitanretlAetaidemretnI
mreTgnoL
sevitanretlA (HFC)
11-R
321-R –
–
21-R
)93PM(A104-R
)66PM(B104-R
)65-XF(A904-R
a431-R
411-R 421-R
205-R
)08PH(A204-R
)01-XF(A804-R
)26PH(A404-R
)06*AELK(A704-R
)05-ZA(705-R
(*VGA)
Evaporator Temperature °F
Normal
Superheat Range
* Ballasted
-20 -40 0 20 40 60
Superheat °F
0
5
10
15
20
* Gas-Cross
Charge (ZP)
Sporlan Selective
Thermostatic Charges
Liquid
Cross Charge (Z)
* Gas
Charge (VG)
Liquid
Charge (L)
* Gas-Cross
Charge
(VCP100)
Liquid
Cross Charge (C)
Figure 6
Table 2
*
KLEA is a trade name of ICI FLUOROCHEMICALS.