Manual
Version
Page
DB04A
EN A1-9
PKP Prozessmesstechnik
18
The size of the pipe must be matched to the measuring/control device. A diameter that is
too small results in an increased pressure drop.
Check for any leaks before commissioning the devices.
For maintenance work, we recommend that a bypass system is used. This is particularly
important where the gas supply must not be interrupted.
Sealants
The design of the devices enables sealing at the ends with O-rings or flat seals. It is
essential
that
you
avoid:
the use of sealing tape to seal threads. Small pieces can cause incorrect measurements
and control-valve malfunctions. As well as that, if the device has to be checked or
recalibrated, there will be an extra charge for the additional cleaning work.
sealing with liquid sealants will incur a higher cleaning charge for cleaning the device in an
ultrasonic tank.
3.13. Fittings and filters
We recommend fittings which are sealed with O-Rings. Than sealing agents or Teflon tape are not
necessary. Some compression fittings are available with an internal 50µ filter.
Please also consider that fittings and filters can create additional pressure drops over the flow
meter.
Please note that the length of the tread on you fitting that is screwed inside the body is for the G¼˝
no longer than 10mm (⅜”) and for the G½˝ no longer than 13mm (½˝) to avoid internal damage.
Installation
The fittings are normally supplied in pairs: they preferably should be installed with filter at the inlet
and without filter at the outlet. The fitting with a filter must be installed at the inlet (as determined by
the flow direction). The sealing rings (O-rings) must not be damaged during assembly.
3.14. Filters / Gas cleanliness
We always recommend that a filter, or at least a fine-mesh sieve (50 microns), is installed before
the measuring devices. It often happens that solid matter such as welding residues, metal or
plastic chips, rust, sealing tape, etc. affect the function.
In pressurized-air applications using compressors, the air must be dry and free of oil. Please
ensure that a suitable processing unit is located before the devices. In the case of gases from
cylinders, in general no filter is needed. For more information, see chapter
5. Maintenance
.
