Spirax Sarco DP27, Installation And Maintenance Instructions Manual

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IM-P470-03 CH Issue 7
12
Pressure sensing pipe
Small bore
drain
Strainer with 100 mesh stainless steel screen
Separator
Steam
supply
Spiratec
sensor
chamber
Float type
steam trap
Pressure
reducing
valve
DP27 and DP27E
0.9 m or 15 pipe diameters
clear on either side
See Section 3.6, page 13.
Downstream isolating valve to
provide no-load conditions for
setting pressure reducing valve
Safety
valve
Discharge
pipe
Check
valve
Strainer
3.2 Fitting
(Figures. 4, 5 and 6)
The valve should always be fitted in a horizontal pipeline with the main diaphragm
chamber below the line (Figure 4). To meet high capacities or widely varying loads, or
where stand-by facility is required, two or more valves may be used in parallel (Figure 5).
For pressure turndown in excess of 10 to 1 consideration should be given to using the two
valves in series. To avoid instability pipework volume between the valves should be equivalent
to at least 50 pipe diameters in length of the intermediate correctly sized pipework. To ensure
adequate drainage of the space between the two reducing valves a trap set should be fitted
as shown in Figure 6.
Separator
Compressed
air
Fig. 4 Recommended installation
Installation for
compressed air
Compressed
air trap
DP27R
Compressed air
Regulator
Filter
Float type
steam trap Alternative for draining separator
Strainer
Sight
glass
Check valve
Steam supply