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172-65185A-08 (MC-COSR Multi-control Valve) 20 Nov 2014
4. Recommended Straight Pipe Runs
In order to ensure stable steam flow, the piping upstream and downstream of the multi-
control valve must be straight runs. If a multi-control valve is installed either directly
before or after an elbow or control valve, unevenness in steam flow may result in
chattering and unstable pressure.
To ensure stable steam flow, it is recommended that the multi-control valve be installed
on straight runs of piping, as illustrated below.
Inlet (primary side) of the multi-control valve
Note: d = pipe diameter
Maintain a straight piping run
of
10 d or more
when a
manual valve, a strainer or an
elbow, etc. is installed.
(Example: if nominal size is
25 mm (1 in), have 250 mm (10
in) or more)
M C -C O SR
10d以上
10d未満
M C -C O SR
Valve, strainer,
elbow, etc.
Valve, strainer,
elbow, etc.
Less than
10 d
10 d or more
Maintain a straight piping run
of
30 d or more
when an
automated valve (on-off valve)
is installed.
(Example: if nominal size is 25 mm
(1 in), have 750 mm (30 in) or
more)
M C -C O SR
30d以上
自動弁
自動弁
30d未満
M C -C O SR
Maintain a straight piping run
of
30 d or more
when another
pressure reducing valve is
installed.
(Two-stage pressure
reduction)
(Example: if nominal size is
25 mm (1 in), have 750 mm (30
in) or more)
30d以上
減圧弁
M C -C O S R
30d未満
M C -C O SR
減圧弁
Outlet (secondary side) of the multi-control valve
Maintain a straight piping run
of
15 d or more
when a
manual valve, a strainer or an
elbow, etc. is installed.
(Example: if nominal size is
25 mm (1 in), have 375 mm (15
in) or more)
M C -C O SR
15d以上
15d未満
M C -C O S R
Maintain a straight piping run
of
30 d or more
when a
safety valve is installed.
(Example: if nominal size is
25 mm (1 in), have 750 mm (30
in) or more)
安全弁
30d以上
M C -C O S R
30d未満
安全弁
M C -C O S R
Maintain a straight piping run
of
30 d or more
when a
control valve or an automated
valve (on-off valve) is
installed.
(Example: if nominal size is
25 mm (1 in), have 750 mm (30
in) or more)
制御弁または自動弁
30d以上
M C -C O SR
30d未満
制御弁または自動弁
M C -C O SR
Automatic
Valve
Automatic
Valve
Less than
30 d
more
or
30 d
Pressure
Reducing Valve
Pressure
Reducing Valve
Less than
30 d or more
30 d
Less than
15 d
15 d or more
Safety
Valve
Safety
Valve
30
ore
d or m
Less than
30 d
Control or
e
Control or
e
Automated Valv
Automated Valv
30 d or more
Less than
30 d
