
Maintenance Manual Edward Forged Steel Valves FCD EVENIM2001-04-AQ – 10/15
8
Reassembly
Valves of the screwed bonnet/ cover type construction are sealed at the
bonnet by flat, soft metal gaskets and “O” Rings. Screwed-in seats are
also sealed by “O” Rings. Such seals require smooth clean surfaces on
body, bonnet or seat. Bolted bonnet valves, such as Figure 848 type,
are sealed with spiral-wound gaskets. In all valves, new gaskets (and
“O” Rings) are recommended for reassembly. Bonnet gaskets (and “O”
Rings) are inexpensive and available out of factory stock.
Valves with screwed bonnet/ cover joints require the bonnet threads to be
well lubricated and tightened to develop sufficient gasket compression.
Bolted Bonnet/Cover Torques
A torque wrench should be used for tightening the bonnet, which is
used to preload the spiral-wound gaskets.
The following procedure is recommended:
1. Guard against leakage by having these capscrews tight at all times.
2. Capscrews should be tightened to the torque shown below.
Bolt diameter, Inches
3 / 8 7 / 16 1 / 2 9 / 16 5 / 8 3 / 4 7/ 8 11-1/ 8 1-1/ 4
Torque, Ft. Lbs.
18 30 45 68 90 150 240 370 585 750
Step #1
Snug to approximately 10% of full recommended torque.
Sequence: 1-2-3
Step #2
Torque to approximately 75% of full recommended torque.
Sequence: 4-3-2
Step #3
Torque to full recommended torque. Sequence: 1-2-3-4
NOTE: The steps for tightening cover capscrews is for the purpose of
pulling the cover down evenly. If this objective can be achieved without
following this suggested method precisely, then some variation from
this method is permissible.
Seat Ring & Bonnet/Cover Torques
Valve Size Figure Number Seat Ring Torque Bonnet/ Cover
Torque
1/ 4, 3 / 8, 1 / 2 158 ,160 75 40
3 / 4 158 ,160 100-120 60
1158 ,160 240-260 125
1-1/ 4, 1-1/ 2 158 ,160 320-340 150
2158,160, 5158,
5160, 9160 400-420 300
Welding Flowserve-Edward Valves into Piping Welding is outside the
scope of this manual, but Flowserve recommends you consult the
appropriate welding procedure in ASME/ ANSI B31, or whatever other
codes apply to your system. When welding Flowserve-Edward valves
into piping, make sure there is no foreign material on the seat joint, then
close the valve tightly to avoid distorting the seats.
After welding, open the valve and flush the line to clean out all foreign
matter.
Lubrication
In order to obtain full service life, valves require periodic lubrication of
the stem threads. Exposed threads should be wiped clean of old grease
and accumulated dirt and fresh lubricant applied. This is most effective-
ly done with the valve in the closed position.
For valves that see frequent operation, such as motor-actuated, the
lubricant should be replenished every three months. If extreme service
conditions dictate, a more frequent relube schedule is recommended.
Motor-actuated valves have a lubricant fitting at the yoke flange.
The recommended lubricant for all stem threads, bonnet, packing nut
and bolt threads is Rykon EP #2, manufactured by the American Oil
Company. This is an extreme pressure, extreme temperature lubricant
of high quality. For valves that are operated infrequently, relubrication
should be at least once a year.