172-65169MA-08 (MC-COS Multi-control Valve) 28 May 2010
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8. Pressure Sensor Installation (for pressure control)
The length of piping
between the MC-COS and
pressure sensor should be
no more than 5 m (17 ft). If
the piping distance is too
great, pressure loss and
delay of pressure change
along this distance will
increase, resulting in steam
flowrate fluctuations. Steam fluctuations at the pressure sensor may impair the
stability of the pressure control. Ensure a straight piping run of at least 15 d
upstream and 5 d downstream from the pressure sensor.
9. Blowdown Valve (requires optional plug)
In an environment of heavy dirt or scale, or when
the steam equipment is used only periodically, such
as for room heating equipment, be sure to use a
blowdown valve.
1. Remove the plug from the (pressureless) main
body.
2. Install the blowdown valve.
3. Open the blowdown valve (while MC-COS is
pressurized) and blow any residual dirt and scale
off the separator screen.
4. Periodically activate the blowdown valve to keep the system free of dirt and
scale.
10. Piping Size / Diffuser
If the secondary steam flow velocity is expected to be more than 30 m/s (100 ft/s),
install a diffuser in order to keep the flow velocity below 30 m/s (100 ft/s). If the
distance between the multi-control valve and the steam equipment is great, a
possible drop in pressure should be taken into consideration when selecting the
piping size.
Straight-run Piping Lengths:
Upstream
Downstream
(d = pipe diameter)
= 10 d or more
= 15 d or more
MC-COS
Diffuser
MC-COS
MC-COS
Remove the
10 mm (
⅜
”)
plug (optional)
and install the
blowdown
valve
Pressure
Sensor
MC-COS
distance of 5m or less
15 d or more 5 d or
more
straight
pipe
straight
pipe
