12
HPS
HPS
HPS
HPS
HPS
®
Square Body LoPro
Square Body LoPro
Square Body LoPro
Square Body LoPro
Square Body LoPro
Seri es
Seri es
Seri es
Seri es
Seri es
12
heat from/to the valve’s pneumatic actuator assembly to/from the body and
the nosepiece of the valve is relatively inefficient, the nosepiece o-ring may
be subjected to significantly higher/lower temperatures without affecting the
pneumatic seals. However, to avoid pneumatic seal damage, the cylinder
temperature should be monitored in the presence of sustained extreme
system or ambient temperatures.
The Rulon LR
5
PTFE bearings supporting the stem are rated for service
between -240
o
C and 287
o
C
6
. Lubricating greases used on the stem, piston
seal, and manual screw increase their viscosity at low temperatures. This
increase in viscosity increases the force required to move the poppet.
Lighter fractions of these lubricants begin to evaporate at temperatures
below 100
o
C, ultimately resulting in dried lubricant, increased friction on the
sliding surfaces, and also increasing the force required to move the poppet.
While the operating temperatures of these lubricants do not pose immediate
problems, regular maintenance, with attention to the condition of the piston,
stem and manual screw lubricants, should be performed on valves run for
extended periods at or near the high temperature limit.
Similarly, the optional limit switch package contains polymers and
elastomers in the switch housings and grommets. The temperature ratings
for these components are as follows
7
:
Switches
-53
o
C to 85
o
C
grommets
-51
o
C to 82
o
C
The wire or cable connected to the limit switches and/or solenoid valve
should be selected for use in the appropriate temperature range.
Optional solenoid operated pneumatic pilot valves also have organic
compounds in their seals and in the insulation of the coil and lead wires. All
Peter Paul solenoid valves normally supplied with Square Body LoPro
valves are rated for operation between 0
o
C and 104
o
C.
1) Polypak is the registered trademark of the Parker Hannifin Corp.
2) PolyPak Seal Design Handbook, 2, (1989)
3) Parker O-Ring Handbook, A3-4 / A3-6, (1991)
4) Kalrez and Viton are the registered trademarks of E.I. du Pont de Nemours Co.
5) Rulon is the registered trademark of Kixon, Division of Furon
6) Guide to dexon Bearings D4
7) Courtesy of Microswitch Division of Honeywell Corp.
Summary of Contents for HPS LPV1-25-AC Series
Page 1: ...HPS Square Body LoPro Series Bellows Sealed Poppet Valves OPERATION AND MAINTENANCE MANUAL ...
Page 2: ......
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