6. Commissioning, operation
6. Commissioning, operation
Personnel: Skilled personnel
Before commissioning the instrument, the conditions from chapter 2.7 "Special
conditions for safe use (X conditions)" must be fulfilled.
6.1 Instruments with threaded connection
The general technical regulations for pressure measuring instruments shall apply
(e.g. EN 837-2 "Selection and installation recommendations for pressure gauges").
When screwing the instruments in, the force required for sealing must not be
applied through the case, but only through the spanner flats provided for this
purpose, and using a suitable tool.
Flange connection
1) The screw connection of the flange must
not be opened
For parallel threads, use flat gaskets, lens-type sealing rings or WIKA profile
sealings at the sealing face . With tapered threads (e.g. NPT threads), sealing is
made in the threads , using a suitable sealing material (EN 837-2).
The tightening torque depends on the sealing used. In order to orientate the
measuring instrument so that it can be read as well as possible, a connection with
LH-RH adjusting nut or union nut should be used. When a blow-out device is fitted
to an instrument, it must be protected against being blocked by debris and dirt.
6.2 Instruments with open connecting flange
The flange sealing must be designed in accordance with the valid standard and
be suitable for the process. Depending on the process conditions and the flange
standard applied, the required fastenings (e.g. threaded bolts, nuts) must be used.
Tighten the screw connections diagonally, step-by-step, with the prescribed tight-
ening torque. For versions with flushing bore, an electrically conductive connection
between the flushing lines or plug screws of the flushing bores and the instrument
WIKA operating instructions pressure gauge model 4 per ATEX
1)
Spanner flats
Sealing face
Installation with
open-ended
spanner
Sealing in the
thread
EN
17