Piping And Installation; Recommended Straight Pipe Runs - TLV COSR-3 Einbau- Und Betriebsanleitung

4. Piping and Installation

CAUTION

4.1 Recommended Straight Pipe Runs

If a pressure reducing valve is installed either directly before or after an elbow or control valve,
unevenness in flow may result in chattering and unstable pressure.
To ensure stable steam flow, it is recommended that the pressure reducing valve be installed
on straight runs of piping, as illustrated below.
q Inlet (primary side) of the pressure reducing valve
• 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"), have 250 mm
(10") 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"), have 750 mm
(30") or more)
w Outlet (secondary side) of the pressure reducing 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"), have 375 mm
(15") or more)
• Maintain a straight piping run of 30 d or more when a
safety valve is installed.
(Example: If nominal size is 25 mm (1"), have 750 mm
(30") or more)
• 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"), have 750 mm
(30") or more)
• 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"), have 750 mm
(30") or more)
• Installation, inspection, maintenance, repairs, disassembly, adjustment
and valve opening/closing should be carried out only by trained
maintenance personnel.
• Take measures to prevent people from coming into direct contact with
product outlets.
• Install for use under conditions in which no freeze-up will occur.
• Install for use under conditions in which no water hammer will occur.
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d = pipe diameter
10 d or more
30 d or more
15 d or more
30 d or more
30 d or more
30 d or more