MKS HPS LPV1-25-AC Series, Operation And Maintenance Manual

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HPS HPS
HPS HPS
HPS
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Square Body LoPro Square Body LoPro
Square Body LoPro Square Body LoPro
Square Body LoPro
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Seri es Seri es Seri es
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8) Teflon is a registered trademark of E.I. Dupont de Nemours Co.
7.4 Limit Switches – Pneumatic Actuation Only
7.4.1 Limit Switch Removal
Be sure to disconnect all power prior to working on or adjusting the limit switches.
This first step applies to NW25 LoPro valves only; for larger valves,
proceed to the next paragraph. Loosen and remove the two 6-32 pan
head screws with star washers on the top of the limit switch housing.
Slide the housing off of the assembly. Sometimes, the wires will hold the
grommets in position as the housing is removed. This is not only
acceptable, but can aid in assembly.
Loosen and remove the four 2-56 pan head screws on the top of the
actuator assembly. (On the NW50 LoPro valves, there are six 2-56 pan
head screws.) Withdraw the limit switch assembly directly away from the
actuator assembly, keeping the central axis of the assembly concentric with
that of the remainder of the valve until it is clear.
7.4.2 Limit Switch Installation
Carefully insert the cam extension into the hole in the center of the bottom
of the limit switch assembly, keeping the axis of the limit switch assembly
concentric with that of the cam extension.
Align the four holes (six in the NW50 LoPro valves) in the top of the cylinder
with the four in the bottom of the limit switch assembly. Insert and tighten
the pan head cap screws.
If the limit switch assembly was previously removed from
the valve it is
being installed upon, and the limit switches functioned properly before
disassembly, readjustment is probably not necessary. Otherwise, see
section 7.4.4 for details on limit switch adjustment.
On the NW25 LoPro valves, install the limit switch housing. Insert
and tighten the two 6-32 pan head screws with star washers in the
top of the housing.
7.4.3 LS Retrofit
With the valve in its closed position, loosen and remove the four 2-56 pan
head screws holding the cover to the top of the cylinder. (On the NW50
LoPro there are six 2-56 pan head screws). Remove the Pisten covers but
Do not remvoe the actuator assembly from the valve body.
Using a 1/8 Allen wrench (5/32 for the NW50 LoPro valves), loosen and
remove the flat head cap screw in the center of the piston. Insert the
threads of the cam extension into the hole in the center of the piston.
Tighten the threads using a 9/16 deep socket or open end wrench. Install