IM-P006-07
CTLS Issue 12
16
Note:
Before actioning any maintenance programme observe the 'Safety information' in Section 1.
Warning:
The body gasket (15) contains a thin stainless steel support ring which may cause physical injury
if not handled and disposed of correctly.
Warning - DP163
The 316 type stainless steel used in the construction of the DP163 product, particularly for screwed
or close fitting parts, is very susceptible to galling or cold welding. This is an inherent characteristic
of this type of material and great care should therefore be taken when dismantling or reassembling.
If the application permits it is recommended that a light smear of a PTFE based grease is applied
to any mating parts before reassembly.
5.1 Routine maintenance
It is recommended that the valve is dismantled once every 12 to 18 months for a complete overhaul and
ideally this should be carried out with the valve removed from the line.
The parts that may require replacing or refurbishing are listed below:
-
Main valve (
17
) and main valve seat (
18
)
-
Pilot valve assembly (
13
)
-
Pilot diaphragms (
9
)
-
Main diaphragms (
23
)
A detailed procedure for servicing the above items is described in Sections 5.3 to 5.9.
In addition to the above items the pushrod (
26
) liner bush, and control pipework and fittings should be cleaned
of any scale deposit if necessary.
5.2 Diaphragms and cleaning
If the valve is dismantled and either the main diaphragms or the pilot diaphragm are not renewed care
must be taken not to turn the diaphragms over - refit them in exactly the same position as when dismantled.
The control orifices in the adaptors of the control pipe assembly (
27
) as well as the balance pipe (
19
or
19A
) must be kept clear of dirt. Blow through with compressed air if necessary - do not use a drill on the
control orifices, as enlargement of the orifices might upset the operation of the valve.
Main diaphragms used in the DP143 and DP163 reducing valves
Size of valve
Diaphragm diameter
DN15, DN15 LC, DN20
125 mm
DN25, DN32
166 mm
DN40, DN50
230 mm
DN80
300 mm
5. Maintenance
Summary of Contents for DP143
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