IM-P006-07
CTLS Issue 12
15
4.1 Start-up
(Setting the valve)
1.
Ensure that all connections are properly made and that all valves are closed.
2.
Check that the adjustment is turned fully anticlockwise until the spring is slack.
3.
Open small valve in pressure control line.
4.
Blow through the approach pipework by removing the cap and screen from the strainer protecting the
steam trap draining the upstream pipework. Replace upon completion. Do not remove the screen from
the main line strainer during this operation. Although this should remove most of the dirt which is present,
it may be necessary to examine and clean the main line strainer at regular intervals.
5.
Slowly open the upstream isolating valve until it is fully open.
6.
Using a 19 mm A/F spanner slowly turn the adjustment screw in a clockwise direction until the desired
downstream pressure reading is obtained.
7.
Holding the adjustment screw in position with the spanner tighten down the lock-nut to secure the setting
of the adjustment spring, making sure that the 'C' washer stays in position (Figure 1).
8.
Slowly open the downstream valve until it is fully open.
4.2 Two or more valves in parallel
When more than one reducing valve is used it is an advantage to use two valves of unequal size, the smaller
one being chosen to meet the lower load requirements and the larger valve to come into operation so that
both meet the normal and maximum demand.
It is necessary to set each valve independently following the start-up procedure detailed in Section 4.1 but
setting the smaller valve at some 0.1 bar higher than the larger one.
Each valve should be set against dead end conditions achieved by closing a downstream isolating valve.
4. Commissioning
Summary of Contents for DP143
Page 2: ...IM P006 07 CTLS Issue 12 2...
Page 28: ...IM P006 07 CTLS Issue 12 28...
