Flowserve F519 Flanged ANSI - Manual (Page 9)

9 REFURBISHMENT INSTRUCTIONS (cont.)
9.2 REBUILDING
a) Before rebuilding, ensure the repair kit and/or components used are suitable for the valve requirement.
When rebuilding, cleanliness is essential for long valve life. The seats may be lightly lubricated with a
light oil to aid bedding in. Ensure that the lubricant is compatible with the pipeline media.
b) Fit a new thrust seal on to the stem shoulder and insert the stem through the valve body from inside
the valve cavity. (On 15mm (½") valves, tweezers will make the job easier).
c) Fit the new gland packings into the body recess and the gland and new disc springs (with their outer
edges touching) on to the stem.
d) Fit the gland nut and preventing the stem from turning, tighten it down to the recommended torque
(see Section 10).
e) Operate the stem several times and re-adjust the gland nut to the specified figure.
The locking clip must then be fitted correctly, either across the corners or on the flats of the nut.
The gland nut can be tightened to the next position to correctly locate the clip (see below).
Over-tightening the gland nut will only reduce the life of the stem assembly.
f) Fit the wrench, spring washer and wrench nut to the stem (if required) and operate the stem to the
valve open position.
g) Fit the body seat into the valve cavity past the stem drive tang,and position it into the seat housing.
h) Turn the stem to the valve closed position and slide the ball into the body, locating on the stem
drive tang.
i) Locate the insert end seat into the cavity and the body seal into its housing.
j) Open the valve, and tighten the insert into the valve body to the torque specified in Section 10 using
the correct drive adaptor. It is important that on stainless steel valves an anti-scuffing compound such
as Rocol 'Copperslip' is used on the insert threads. It is advisable, though not mandatory to use it on
carbon steel valves as well.
k) If practical, leak tightness and operating torque should be checked prior to refitting the valve in line.
Correct
Incorrect Incorrect
Correct