Valve Maintenance - Flowserve Valtek FlowTop V746 User Instructions

WARNING
while the valve is in operation.
Prior to start-up, we strongly recommend that you:
1. Stroke the valve and compare the plug position
indicator on the stem clamp to the stroke indicator
plate. The plug should change position in a smooth,
linear fashion.
NOTICE
2. Adjust instrument signals to ensure a full stroke.
3. Check the packing box bolting to ensure the correct
adjustment (See Section 11: Valve Maintenance).
NOTICE
that may impede plug movement.

11 Valve Maintenance

Maintenance intervals and service life of a valve can only be
determined empirically on site. The intervals specified in the
User Instructions are recommendations and serve only as a
guide. Under problematic operating conditions, maintenance
intervals may be significantly reduced. We strongly recom-
Service
No.
1 Visual inspection of
the valve
2 Visual inspection of
the packing
Preventive change of
the PTFE-packing
3 Visual inspection of
body bolting
4 Visual inspection of
the actuator
5 Preventive overhaul of
the valve
6
Operation test
8
Due to risk of crushing hazard, do
not work between the yoke legs
If over tightened, excessive friction
may impair smooth control.
Over tightening can cause excessive
packing wear and high stem friction
Recommended Maintenance Actions
Inter-
val
Good
Bi- No action
weekly
Bi- No action
weekly
Dependent upon results of previous maintenance (see numbers 1 and 2 above) or a
minimum of once every 24 months
Yearly No action
Bi- No action
weekly
Dependent upon results of previous maintenance (see numbers 1 to 4 above) or a
minimum once every 60 months
No action
Valtek FlowTop General Service Valve
4. Continuously increase load until operation parameters
are reached.
5. Minor relaxation of the flange bolting is possible after
initial assembly. Retorque the bonnet flange bolting
if necessary before installation or following an initial
temperature excursion to ensure the bonnet gaskets
do not leak (See Table 4).
Size
1/2"
3/4"
1"
1 1/2"
2"
3"
4"
6"
Table 4: Recommended Body Bolt Torque Values
mend a site survey followed by establishing a documented
procedure for performing the maintenance work. Maintenance
personnel should perform and log the work accordingly. The
data collected can be used as a basis for dynamically deter-
mining the maintenance intervals and activities.
Valve Condition
Adequate
Clean valve stem with a soft
cloth
Retighten leaky packing box
Retighten body bolting if
bonnet gasket leaks.
Clean actuator stem with a
soft cloth
Perform 3 full strokes if packing and / or bonnet tightening is
modified; check for leakage
FCD VLENIM8610A4 11/18
Pressure Class 150
1)
Nm ft lb
15 11
23 17
28 21
24 18
41 30
72 53
V746 is designed for Class 150 while V748 is desigend for Class 300
1)
Inadequate
Overhaul or replace valve after product
lifecycle
Replace leaky packing box immedi-
ately
Remove from service and replace body
bolting immediately if gasket leakage
persists or if bolting is damaged
Overhaul or replace actuator after prod-
uct lifecycle
Class 300
1)
Nm ft lb
15 11
24 18
32 24
37 27
71 52
146 108