Tecfluid COVOL Series - Manual (Page 9)

9
4.1 Disassembly
The list of the different elements is shown in the chart and figure in “Part List” on page 11.
The device consists of the following elements:
- Flowmeter body (chamber and connections)
- Oscillating piston
- Inlet / outlet separator
- Chamber guide disks (2 off)
Flowmeter body
The disassembly of the body should be started at the side marked with the number 2, and
this is done by loosening the hexagonal bolts (8) situated on the periphery of the cups (1)
and central ring of the counter (4).
Once loosened and removed (it only has to be done on the number 2 side of the counter),
we can detach the cup (1). The o-ring (2) and the smooth exterior part of the metering
chamber's disk (3), marked with number 1, can now be seen.
The disk (3) has a threaded hole that takes a screw to allow us to withdraw the disk
smoothly.
The disk should be withdrawn perpendicularly, uncovering the metering chamber (4) with
the rotary piston (10) and inlet/outlet separator (5).
The piston (12) is easily removed and it has a drop form opening to fit the inlet/outlet
separator (5) which acts as a guide for the rotation of the piston.
The inlet/outlet separator (5) joins the metering chamber ring to the central circular guide
of the guide disk (3). It can be removed by pulling it out perpendicularly.
In this way the metering chamber (4) is completely dismounted for inspection and
thorough cleaning if necessary.
If the metering chamber (4) is damaged due to the effect of abrasive products or non-
filtered hard particles that scratched its inner wall, said chamber must be machined at
Tecfluid S.A. facilities and proceed with the re-adjustment with a new rotary piston as well.
In case it was necessary to clean the chamber (7) marked with number 1, the external
screws (13) must be loosen. Once removed the inlet chamber, the gasket and the
external smooth side of the inlet guide disk (6) can be seen.
Then the cleaning of all components can be carried out.
Rotary piston
This is the only mobile piece of the COVOL oscillating piston flowmeter.
It has a long life due to the Teflon and graphite composition, that makes it very wear
resistant and gives it a low friction coefficient.
Premature wear can only be due to abrasive products and flow rate higher than those
indicated in the table of page 8, which can cause excessive knocks at the inflection point
of the oscillating turning of the piston, producing breakage at very high speeds. Other
materials for the piston can be used depending on the application without affecting
significantly its working life. Non-filtered particles can also damage the piston.
4.2 Mounting
If the flowmeter body has been completely disassembled, reassembly should start by
placing the guide disk (6) in the metering chamber (4), matching the positioning hole with
the metering chamber (4) pin. Then place the o-ring and the inlet chamber (7), which is
marked with number 1.