Hansen PXV Series Operating instructions

INTRODUCTION
The Hansen PXV and PXVW are pulse modulating liquid
refrigerant expansion valves. The PXV uses a specially
designed, high-cycle, long life, solenoid operator. A
sophisticated 4-20 mA input signal is used to monitor
the liquid flow to the system. Unlike traditional TXVs,
the pulse design eliminates the need to maintain
minimum pressure differential. Low and varying liquid
feed pressures (head pressure) are compensated by
the basic variable valve operation. It is suitable for use
with ammonia and most common refrigerants.
The unique PXVW60 body has an integral 100 mesh
(150 micron) strainer screen and features direct weld
assembly, eliminating flange gasket leak potential. In
addition, the PXVW valve has an adjustable, integral
hand-expansion plug to regulate the flow from 15 to
60 nominal tons of ammonia. Consult the factory for
PXVW halocarbon capacities.
APPLICATIONS
The PXV modulates the flow of liquid feed to an evaporator
or chiller. It is recommended for use wherever a thermal
expansion valve (TXV) would be used. It is also ideal for
liquid make-up to small surge vessels above flooded
heat exchangers to minimize fluctuations in liquid level
and evaporator pressures, and for liquid injection for
compressor oil cooling.
KEY FEATURES
• PXV5, PXV15 drop-in replacement valve for
Sporlan DA series thermostatic expansion valve
• PXV does not require minimum pressure drop to
operate; low head pressure tolerant
• PXVW60 with adjustable capacity settings from
15 to 60 nominal tons of ammonia
• Simple, compact controller programmed for liquid
level control, liquid injection oil cooling, or DX
superheat control
• Operates with 115V, 220V, or 24V AC coil
FLANGED CONNECTION
DROP-IN FOR SPORLAN
DA SERIES TXV
STEM TO
ADJUST CAPACITY
OF VALVE
1/2" TO 3/4"
WELD-IN-LINE
CONNECTION
PXV
PXVW
SPECIFICATIONS
Body:
PXV: Ductile iron, ASTM A536 (Flanged Valve)
PXVW: Cast Steel, ASTM A352, grade LCB
Seat Disc: Teflon
Valve Seat: 303 Stainless Steel
Safe Working Pressure:
400 psig (28 bar)
600 psig (40 bar) available upon request
MOPD: 285 psi (19.7 bar)
Refrigerant Temperature: –60°F to +240°F (–50° to 115°C)
Refrigerants: ammonia, R22, R404, R507, R134a,
CO2, and other Hansen approved refrigerants
Specifications, Applications,
Service Instructions & Parts
PULSE WIDTH CONTROL
EXPANSION VALVE
(PXV & PXVW)
Bulletin P249
OCT 2013
Pulse Width Modulated Liquid
Level Control, DX Evaporator and
Liquid Injection for Refrigerants
PXVWPXV

2
P249
OCT 2013
CAPACITY
The PXV models are available for ammonia capacities
up to 60 nominal tons with adjustable capacity settings.
The PXV models available for ammonia are 5 and
15 tons (nominal) and the PXVW has an adjustable
hand-expansion plug from 15 to 60 tons (nominal).
LIQUID LINE SIZING
Liquid lines should be adequately sized for the capacity of
the valve. Listed below are the recommended capacities
for liquid lines.
LINE
SIZE
MAXIMUM CAPACITY
AMMONIA
MAXIMUM CAPACITY
R-507
1/2˝ 32 Tons 112kW 4 Tons 14kW
3/4˝ 58 Tons 208kW 8 Tons 28kW
1˝ 97 Tons 340kW 13 Tons 46kW
NH3 capacities are based on IIAR Refrigeration Piping
Handbook tables.
R-507 capacities are based on 3 ft/s liquid velocity. For
R-134a, use 160% of R-507 capacity; R-404 140%.
INSTALLATION
Match the arrow on body with system flow direction.
The PXV and PXVW may be installed in both horizontal
and vertical lines. For DX evaporator, install as close
as possible to the distributor in vertical down-flow line
(recommended). When installing PXV valve to distributor,
remove the expansion orifice plug. Allow 2.2˝ (57 mm)
above the valve for coil removal, 1˝ (25 mm) below for seal
cap removal, and 3˝ (76 mm) below strainer for screen
removal. For proper flange gasket sealing, care must
be taken when threading or welding to assure flanges
are parallel to each other and perpendicular to the pipe.
Also, gaskets should be lightly oiled and all bolts must
be tightened evenly.
The PXVW is a weld-in-line valve available in butt weld
and socket weld connections. If welding is prolonged
enough to overheat the valve body, a wet rag should
be wrapped around the valve bonnet and upper body
while welding. Socket weld fitting and valve codes
require that the pipe be inserted until bottomed against
the stop, then backed out approximately 1/16˝ (1.5 mm)
before welding.
Welds should be annealed as necessary in accordance
with good practice. Painting valves and welds is
recommended for corrosion protection. Pipe covering,
where applied, should have a proper moisture barrier.
Before putting valves into service, all pipe weld
connections, bonnet seals, and stem seals should
be tested for leaks at pressure levels called for in
appropriate codes.
EVAPORATOR TONNAGE (kW)
CAT NO CONNECTION CAPACITY IN TONS (kW)
SIZE STYLE AMMONIA R-404/R-507 R-134aR-22 CO2
PXV5 1/2˝ FPT, SW 5 (18) 7 (25) 1 (4) 2 (7) 2 (7)
PXV15 1/2˝ FPT, SW 15 (53) 4 (14) 4 (14) 5 (18) 8 (28)
PXVW60
1/2˝, 3/4˝ SW 15 to 60
(53 to 212)
ADJUSTABLE
5 to 15
(18 to 53)
ADJUSTABLE
5 to 20
(18 to 70)
ADJUSTABLE
6 to 27
(21 to 95)
ADJUSTABLE
9 to 45
(32 to 158)
ADJUSTABLE
1/2˝, 3/4˝, 1˝ BW
5/8˝, 7/8˝, 1-1/8˝ ODS
R-404, R-507, R-134a, and R-22 capacities are based on a pressure drop of 80 psid (6 bar) or higher.
PXV, PXVW AMMONIA EXPANSION CAPACITIES (TONS)
CAT NO PRESS. DROP (PSI) 20 40 60 80 100 120 140 160
COND. TEMP (°F) 22º 38º 59º 61º 70º 79º 86º 93º
PXV5 –0.044 CV 3 3 4 5 5 5 6 6
PXV15 –0.187 CV 11 14 17 19 21 22 24 25
PXVW60
(ADJUSTABLE
ORIFICE)
TURNS IN CV
0–1 1.00 57 77 92 103 112 119 126 132
1½ 0.96 55 74 88 99 107 115 121 127
20.87 50 67 80 89 97 104 110 115
2½ 0.65 37 50 60 67 73 78 82 86
30.55 31 43 51 57 62 66 69 72
3½ 0.35 20 27 32 36 39 42 44 46
40.21 12 16 19 22 24 25 26 28
4½ 0.13 710 12 13 15 16 16 17
5–7 0.09 5 7 8 9 10 11 11 12
FU LLY I N MANUALLY OPEN
Capacities are based on 0ºF evaporator and pressure drop. For other evaporator temperatures and corresponding pressure drop
the capacities are within 10%.
PXVW60 adjustable for Cv=.10 to 1.0

3P249
OCT 2013
TYPICAL APPLICATION: DIRECT EXPANSION EVAPORATOR, PXV/PXVW
FIGURE 1
FIGURE 2
DX EVAPORATOR
EXPANSION VALVE
PRESSURE TRANSDUCER
(10:00 - 2:00 POSITION)
PXV
PXVC - PT
CONTROLLER
INSULATION
TEMPERATURE
SENSOR AT
4 OR 8 O'CLOCK
POSITION
PIPE
TEMPERATURE
SENSOR
TO PROTECTED SUCTION
DX EVAPORATOR
EXPANSION VALVE
4-20 mA
PRESSURE/TEMPERATURE
TRANSDUCER (HPT)
(10:00 - 2:00 POSITION)
PXVW
PXVC - DX
CONTROLLER
TO PROTECTED SUCTION

4
P249
OCT 2013
OPERATION – LEVEL CONTROL (Figure 3)
The Hansen PXVC-L controller is factory programmed
to provide precise control of liquid level in flooded
evaporators, small liquid recirculators, and other
refrigerant level vessels. A 4-20mA input signal from
the Hansen VLT level probe, Hansen Vari-Level with
MOD420 Output Module, or other liquid level device
to the Hansen PXVC-L controller pulses the PXV valve
open and closed at a rate equal to the refrigerant flow
necessary to maintain a set-for liquid level in the vessel.
For a wiring diagram, refer to Figure 8 on page 9.
TYPICAL APPLICATIONS – PXV AND PXVW
TYPICAL FLOODED CHILLER APPLICATION
FIGURE 3
EXPANSION VALVE
SURGE VESSEL
PXV OR PXVW
PULSE WIDTH
OR TECHNI-LEVEL VLT
VARI-LEVEL (WITH MOD420)
CUSTOMER SUPPLIED HANSEN
FOR LIQUID LEVEL
PXVC-L CONTROLLER
OPERATION – LIQUID INJECTION (Figure 4)
The Hansen PXVC-T controller is factory programmed to
provide precise control of temperature in applications
such as liquid injection to screw compressors. An NTC
temperature sensor available from Hansen provides an
input signal to the Hansen PXVC-T temperature controller.
This controller pulses the PXV valve open and closed
at a rate equal to the refrigerant flow necessary to
maintain a set-for discharge gas temperature. If valve
is controlled with a compressor controller or PLC, the
fastest cycle time recommended is once every six
seconds for prolonged life. For a wiring diagram, refer
to Figure 7 on page 8.

5P249
OCT 2013
OPERATION – DX EVAPORATOR
(Figures 1 & 2)
Through the use of pulse width modulation, the valve
is cycled on and off to achieve a desired flow. The
recommended fastest cycle time is once every 6 seconds
for prolonged life. During a cycle, the valve can be
open anywhere from 0 to 6 seconds. The more “on”
time required, the greater the flow through the valve.
The correct amount of “on” time can be determined by
monitoring superheat (see HPT Pressure/Temperature
Transducer Bulletin PT100). If actual superheat is greater
than desired, the pulse width signal is increased to
provide more valve “on” time. If actual superheat is
less than desired, the pulse width signal is decreased
to reduce valve “on” time. See Figures 5 and 6 on page
6 and 7 for wiring diagrams.
TYPICAL APPLICATIONS – PXV AND PXVW
TYPICAL LIQUID INJECTION COOLING FOR SCREW COMPRESSOR APPLICATION
FIGURE 4
For systems using the PXVW valve, the integral hand-
expansion stem capacity must be adjusted to match the
capacity of the evaporator. See the chart on page 2 for the
approximate settings. During operation, the stem can be
adjusted in if it is off too long (capacity setting too high),
or out if it is nearly always on (capacity setting is too low).
When using ammonia as the refrigerant, installation
should be in the vertical down position directly
connected to the distributor. (See Figures 1 & 2). Vertical
down installation close to the distributor helps ensure
homogenous mixing of gas and liquid entering the
evaporator. This is particularly important for applications
using multi-circuit, air cooling evaporators. Note: Suction
lines from DX evaporators should go to a suction trap
to protect compressors from liquid carryover that may
result from system upsets.
PXV OR PXVW
PULSE WIDTH VALVE
PXVC-T
TEMPERATURE
CONTROLLER

6
P249
OCT 2013
TYPICAL WIRING DIAGRAMS
DX EVAPORATOR CONTROL (PXVC-PT)
(Using Separate Pressure Transducer and Temperature Sensor)
FIGURE 5

7P249
OCT 2013
TYPICAL WIRING DIAGRAMS
DX EVAPORATOR CONTROL (PXVC-DX)
(Using Hansen HPT 4-20 mA or Customer Supplied 4-20 mA Superheat Input)
FIGURE 6

8
P249
OCT 2013
TYPICAL WIRING DIAGRAMS
TEMPERATURE CONTROL
FIGURE 7

9P249
OCT 2013
TYPICAL WIRING DIAGRAMS
LIQUID LEVEL CONTROL
FIGURE 8

10
P249
OCT 2013
PXV INSTALLATION DIMENSIONS
INCHES (MILLIMETERS)
PXV PARTS LIST
8
5
1
2
6
7
10 9
4
3
11
12a 12b
13
*
ITEM DESCRIPTION QTY PART NO.
1a
1b
1c
1d
2
5
6
7
8
2
7
4
3
10
4
9
11
12a
12b
13a
13b
Coil Kit(115V) 1/2˝ Fit w/ Leads
Coil Kit(208/230V) 1/2˝Fit w/ Lds
Coil Kit (24V) 1/2˝ Fit w/ Leads
Coil Kit (Other Voltages)
Above kits consist of:
Bare Coil, 115V 50/60HZ w/ Leads
Bare Coil, 208/230V 50/60HZ w/ Lds
Bare Coil, 24V 50/60HZ w/ Leads
Other Voltage Coils
Coil Knob
PXV Solenoid Tube/Plunger Kit
Above kit consists of:
Long life Plunger
Solenoid Tube
Solenoid Tube O-Ring
Tube Screws
Coil Knob
PXV Gasket Kit
Above kit consists of:
Solenoid Tube O-Ring
Strainer Cap O-Ring
Flange Gasket
Strainer Screen Kit
Above kit consists of:
Screen Assembly, 100 mesh
Strainer Cap O-Ring
Strainer Cap
PXV Body
Expansion Orifice Plug, 5 Ton(3/64˝)
Expansion Orifice Plug, 15 Ton (5/64˝ )
1/2˝ FPT Flange
1/2˝ SW Flange
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
1
1
1
2
1
1
1
1
1
1
1
2
2
70-1085
70-1086
70-1087
FACTORY
70-0580
70-0581
70-0582
FACTORY
70-0579
70-1072
70-0467
70-0298
72-0066
70-0297
70-0579
70 -113 4
72-0066
72-0066
20-2390
78-1010
78-0072
72-0066
72-0065
FACTORY
70-0745
70-0746
30-0164
20-1520