Flowserve V-370 R3 Edward Valves - Manual (Page 16)

EDWARD UNIVALVE USER INSTRUCTIONS ENGLISH 12-13
16
GENERAL: Be sure all parts are clean of dirt, rust or scale.
Packing Installation
If the Univalve packing was sealing well and has not been
removed, it can be reused. However, if leaking, or if it has
been removed from the bonnet, it should be replaced. We
recommend packing be purchased from Edward Valves
to assure packing with the proper density and corrosion
inhibitors is always used.
IMPORTANT: Long service life from modern graphitic
packing requires that adequate preloads be applied when
repacking.
• All parts should be clean and not scored or pitted,
especially the stem.
• The stem, disk and bonnet should be in the valve prior
to installing the new packing.
• Position split packing with the ends of adjacent rings
rotated 90°.
• Standard packing:
– Top Ring: Braided Carbon Fiber Ring
Note: Class 4500 valves use two (2) top rings
– Center Ring: Flexible Graphite Ring
– Bottom Ring: Same as top (Class 4500 has only one
[1] ring on bottom).
• Clean and lubricate the gland screws.
• Tamp the packing down by hand using the gland.
• IMPORTANT: Apply the recommended torque to
the gland bolts evenly without cocking the gland.
See pg. 15 for torques.
• Stroke the stem and then recheck the torque on the
gland bolts.
REASSEMBLY OF THE UNIVALVE (continued)
Packing Chamber Schematic
ft-lb: Bold face numerals are feet-pounds.
N-M: Regular face numerals are in newton-meters.
Figure Number
Valve Size
1/2 3/4 1 1-1/4 1-1/2 2 2-1/2 3 4
All
50
70
100
135
WELDED UNIVALVE BONNET TORQUES