Emerson TESCOM 04 Series Safety, Installation, Operations & Service page 8

Section 3
Rev. 06/15
stop random contamination resulting from the installation of the regulator. An auxiliary
upstream filter is recommended for use in all but the cleanest media. Gaseous media
should be free of excessive moisture to prevent icing of the regulator at high flow rates.
A regulator is not intended to be used as a shutoff device. When the regulator is not
in use, the inlet supply should be turned off. As a safety precaution, a pressure relief
device should be installed downstream of the regulator.
3.2.4 Maintenance
The following procedures are provided to enable the customer to perform all normal
maintenance and repair operations. These operations are more easily performed with the
regulator removed from the line. However, in some cases repair may be accomplished
without removal of the regulator body as long as the supply has been shut off and the inlet
and outlet pressures have been vented.
An Assembly Drawing and Bill of Material for the regulator will be needed to complete
maintenance procedures. The Assembly Drawing and Bill of Material are separate from this
manual and available by contacting TESCOM (see pg. 39 for TESCOM contact information).
The following steps outline the disassembly of pressure reducing regulators for
maintenance and repair:
1. Clamp the regulator in a vise by the flats on the bottom and/or side of the regulator
body.
2. Turn control knob and/or spring adjustment mechanism counterclockwise to insure
removal of all spring force on the diaphragm.
NOTE: (Dome loaded regulators) All pressurized gas or liquid must be vented from dome
before disassembly.
3. Remove upper portion of regulator (bonnet and/or dome). Some models require the
mounting bracket to be removed first.
NOTE: Upper portion of regulator may also include spring button, load spring back-up
plate, and diaphragm, etc. Review correct drawing to ensure that all parts have been
disassembled.
NOTE: (Two-Stage Regulator) TESCOM Model Series 44-3400, 64-3400 and PS3400 are
two-stage regulators that have portions on both ends of the regulator body that must be
removed. It is TESCOM's recommendation that two-stage regulators be returned to the
factory for repair.
4. The valve parts can now be removed from the regulator body by turning the seat
retainer and/or back cap counterclockwise until it is free of the regulator body.
When removing valve parts from a regulator that has a back cap, care must be taken
to insure the main valve stem remains vertical. If the main valve stem is not removed
correctly, parts may remain in the regulator.
5. To disassemble main valve assembly and/or valve, clamp valve in smoothed jaw vise or
hold with pliers. Clamping should be done on flats.
Safety, Installation, Operations & Service Manual
8
DOPSM2080X012