Cleaning With Pigs; Seals; Nominal Diameter And Flow - Endress+Hauser Dosimag Operating Instructions Manual

Installation
20
4. Reinstall the sensor in the pipe, and in doing so make sure that the seal is clean and
in the right position.
• If thin-walled pipes carrying food are welded correctly, the seal is not damaged by
the heat even when mounted. However, it is recommended to disassemble the
sensor and seal.
• It must be possible to open the pipe by approx. 8 mm (0.31 in) in total to permit
disassembly.
5.2.3

Cleaning with pigs

It is essential to take the internal diameters of the measuring tube and process connection
into account when cleaning with pigs. All the dimensions and lengths of the sensor and
transmitter are provided in the separate "Technical Information" document.
5.2.4

Seals

When mounting the process connections, make sure that the seals in question are dry,
clean, undamaged and correctly centered.
• The screws must be firmly tightened. The process connection forms a metal
connection with the sensor, which ensures a defined compression of the seal.
• Depending on the application the seals should be replaced periodically, particularly
if molded seals are used (aseptic version)!
The interval between changes depends on the frequency of the cleaning cycles, the
cleaning temperature and the medium temperature.
Replacement seals can be ordered as an accessory.
5.2.5

Nominal diameter and flow

The diameter of the pipe and the flow rate determine the nominal diameter of the sensor.
The optimum velocity of flow is between 1 to 4 m/s (3.28 to 13.12 ft/s). The velocity of
flow (v), moreover, has to be matched to the physical properties of the fluid:
• v < 2 m/s (6.56 ft/s): for abrasive fluids such as cleaning agents etc.
• v > 2 m/s (6.56 ft/s): for fluids producing buildup such as liquids that contain oil and
sugar
A necessary increase in the flow velocity can be achieved by reducing the sensor
nominal diameter.
Flow characteristic values in SI units
Nominal diameter
[mm]
4
8
1)
15K
15
1) Conical version (corresponds to DN 12)
Recommended
flow
Maximum full scale value
[l/s]
0.14
0.5
1.2
1.66
Dosimag
Factory settings
Low flow cut off
Pulse value
(v ~ 0.04 m/s)
[ml] [ml/s]
0.005 0.5
0.02 2
0.1 7
0.1 7
Endress+Hauser