![MKS HPS LPV1-25-AC Series Operation And Maintenance Manual Download Page 39](http://html.mh-extra.com/html/mks/hps-lpv1-25-ac-series/hps-lpv1-25-ac-series_operation-and-maintenance-manual_1813369039.webp)
31
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
Serie s
specifications. Movement in jumps, called slip sticking, can be observed
through the same hole. The vibration caused by slip stick jumps can often be
felt manually and sometimes heard.
First, see section 8.3.15 on inadequate air pressure. If pneumatic pressure
is within recommended limits, refer to section 8.3.16 covering inadequate
airflow. Lastly, see section 8.3.14 on inadequate or exhausted lubrication.
8.1.4 Won’t open at all
Continuation of the signal from the closed limit switch (if so equipped) and
zero conductance through the valve are both good indications that the valve
has not opened. Visual observation of the piston’s failure to move can be
made through the hole in the center of the piston cover.
First, see section 8.3.15 on inadequate air pressure. If pneumatic
pressure is within recommended limits, refer to section 8.3.19 on stem
weld failure. Last, if air is blasting from around the piston hold down
screw when the valve is trying to open, see section 8.3.13 on loose
piston hold down screws.
8.1.5 Squeaks when opening and/or closing
LoPro valves normally make a barely audible squeak when they open. This
is caused by the spring making contact with the bushing that prevents the
spring from buckling and damaging critical components.
A loud grinding or squeaking may be indicative of a problem. If there seems
to be loose components rattling about inside the valve, see section 8.3.1 on
spring failure. Also check section 8.3.14 on inadequate lubrication.
8.1.6 Leaks across closed nosepiece seal
Detection of leakage across the nosepiece seal when the valve is closed
can be symptomatic of several problems. See section 8.1.1 if the valve also
isn’t closing completely.
Refer to section 8.3.11 on nosepiece seal omission. If the o-ring is present,
particles, contamination, and corrosion may be the problem, see section
8.3.4. If the valve continues to leak after the seat and sealing area have
been cleaned, see section 8.3.7 on bonnet seal failure.
8.1.7 Leaks from atmosphere when closed
If leakage is detected from atmosphere when the valve is closed, see
section 8.3.12 on improper assembly. If the assembly is correct,
refer to section 8.3.7 on bonnet seal failure. Lastly, see section 8.3.2
on body damage.
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: ......
Page 51: ......
Page 52: ......