ARI Armaturen ASTRA DN250-400 EN - Manual (Page 10)

Page 10 Rev. 0040105004 0212
Operating and installation instructions
ASTRA
®
9.0 Troubleshooting table
ATTENTION !
- read point 10.0 and 11.0 prior to dismantling and repair work!
- read point 6.0 before restarting the plant !
Fault Possible cause Corrective measures
No flow Valve closed Open valve
Flange covers not removed Remove flange covers
Little flow Valve not sufficiently open Open valve
Dirt screen clogged Clean / replace screen
Piping system clogged Check piping system
Valve difficult to move or
cannot be opened Wrong direction of rotation Turn in correct direction (anticlockwise
to open valve)
Valve spindle leaking EDD-special spindle seal Replace valve or bonnet.
Stuffing box gland DN250-400 (pos. 17)
slack (Fig. 4) Tighten stuffing box gland (pos. 17)
with hexagon nut (pos. 23) until leak-
age stops;
Replace top part at earliest opportunity!
If necessary, renew packing in stuffing
box seal (pos. 6). Observe warnings!
Leakage across valve seat Valve not properly closed Pull hand wheel tight without tools
Seat (pos. 1) / plug (pos. 3) damaged
by foreign particles. (Fig. 2) Replaced valve, consult supplier/man-
ufacturer
Pressure difference too high Check system pressure and pressure
drop (max.
Δp = 16 bar);
Reduce system pressure.
Medium contaminated
(suspended solids) Clean valve;
Install dirt screen upstream of valve
Valve with stroke limiter
cannot be opened Stroke limiter on spindle stop has been
tightened Turn stroke limiter upwards
Flange broken between
valve and piping Bolts tightened unevenly.
Mating flanges not properly aligned Re-align piping and fit new valve!
Display does not show “0”/
“0” when valve is closed Display not fitted properly after pipe was
lagged Close valve, unscrew cap (pos. 23),
remove hand wheel and digital display,
set display to “0”/“0” and reassemble in
reverse order. (See point 5.2)
False data recorded False data displayed See point 5.2;
Observe operating instructions for
measuring instrument used