9
IOM
4.
PERIODIC MAINTENANCE
Please note that the periodic maintenance of the air valve is an integral part of the proper pipeline
maintenance regime; it should be maintained at least once a year in accordance with the quality and
composition of the fluid in the system.
Important: Before performing any work on the air valve, make sure that all workers on site are familiar with the
safety instructions as appear chapter of this document and with all the relevant local and general safety
instructions, standards and work regulations.
4.1.
Preparation
Releasing Pressure
Shut the isolating valve located on the riser under the air valve.
Option A:
Using two combination spanners, partially unscrew the bolts connecting the air valve to the riser in order
to release the pressure. Wait till the pressure is released.
Option B. – for air valves with Plug:
Use a ratchet box wrench to gradually release the Plug of the pressure release port, wait till the pressure
is released and then unscrew the Plug completely, remove it and drain the air valve.
4.2 Maintaining the Air & Vacuum valve
Refer to the drawing on the next page.
1.
Shut the isolating valve below the air valve.
2.
Unscrew the Bolts that connect the valve Cover to the valve Body.
3.
Remove the Cover assembly from the valve Body
4.
Wash and clean the following parts: Body including the groove of the O-ring, Screen, Float, and Cover
including the Orifice Seat and Orifice Seal under clean running water in order to remove coarse grime
and/or accumulated scale.
5.
Check that the Orifice Seal is not damaged (torn and/or cracked).
6.
In case the Orifice Seal is damaged, consult your dealer.
7.
Reassemble the air valve in the reverse order:
8.
First insert the Float, and then place the O-ring in the groove.
9.
Place the Cover on the Body, insert the Bolts and Washers and tighten the Nuts.
10.
Tighten all the Bolts and Nuts using the crossover method.
11.
The closure tightness of the Bolts and Nuts shall be according to the standard torque for their specific
size.
12.
Use ring wrench keys (Hand force only) for the closing and opening of all Bolts of the air valve (including
the flange bolts).