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HPS
HPS
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Square Body LoPro
Square Body LoPro
Square Body LoPro
Square Body LoPro
Square Body LoPro
Seri es
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8.2 Problems and Diagnosis Manual Actuation
8.2.1 Won’t close completely
High magnitude leakage across the nosepiece seal when the valve is
supposedly closed is evidence for failure to close completely. In valves that
have visual access to one or both of the ports, a gap between the
nosepiece and the seat might be observed.
If the gap between the nosepiece and seat is large (greater than .1") or
there seems to be loose components rattling about inside the bellows, see
section 8.3.12 covering improper assembly. If the gap between the
nosepiece and seat is small (less than .1") see section 8.2.4.
8.2.2 Won’t open completely
Failure to open completely can be detected directly by the manual screw
not reaching full extension. A significant decrease in the valve’s
conductance may also be an indication. See section 8.3.12 covering
improper assembly.
8.2.3 Difficult to open/close or Squeaks
Square Body LoPro valves normally make a barely audible squeak when
they open. An Increase in squeaking and opening difficulty usually
indicates inadequate lubrication on the manual screw.
First, see section 8.3.14 on inadequate lubrication. If the manual screw is
properly lubricated, see section 8.3.12 on improper assembly.
8.2.4 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 8.2.1 if the valve 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.
8.2.5 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
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