6
8. Maintenance
During maintenance the following rules should be observed:
・
Startup process – Sudden changes of pressure and temperature should be
avoided when starting the plant.
・
Strainers – Wire mesh filters do not contain moving parts and do not require any
maintenance, with the exception of screen cleaning.
・
Strainer screens require regular cleaning – Screen cleaning intervals should be
established by the user depending on how dirty the the medium is.
Before taking up any service jobs make sure that the medium supply to the
pipeline has been cut off, the pressure has been decreased to ambient pressure,
the medium has been removed from the pipeline, and the plant has cooled down.
・
Cleaning or replacement of the screen is possible when body / cover bolt nuts are
unscrewed and the screen is taken out of the strainer. Remove sludge from the
screen by washing it in water, without using metal tools.
・
Some of the sludge can be removed by unscrewing the plug from the cover if the
strainer is provided with a plug.
・
Before strainer reassembly remember to replace the body / cover gasket.
Precautions should be taken when touching the gasket between the body and the
strainer cover. The gasket contains a metal core which may cause injury,
・
Tighten the hexagon nuts of the cover bolts evenly and crosswise using a torque
wrench.
In order to assure safe performance, each strainer (especially those that are
rarely used) should be surveyed on a regular basis. Inspection frequency
should be determined by the user, but should not be less than once per month.
9. Service and Repair
All service and repair jobs should be carried out by authorized staff using suitable tools
and original spare parts. Before removing the strainer from the pipeline or before
service, the pipeline should be out of operation. During service and repair jobs:
・
The pressure should be decreased to 0 bars and strainer temperature to ambient
temperature.
・
Appropriate personal protective gear should be used at all times.
・
After strainer removal it is necessary to replace the flange connection gaskets
between the strainer and pipeline.
・
Tightening torques for body / cover bolts
Screw
M8 M10 M12 M16 M24
Torque (N
⋅
m)
15 – 20
35 – 40
65 – 70
140 – 150
350 – 400
・
Before reinstalling the strainer in the pipeline it is necessary to check strainer
operation, and tightness of all connections. A tightness test should be carried out
with a water pressure of 1.5 times the nominal pressure of the strainer.
TEG-Y8F-M-00 20 August 2013
