2 L12 71 en
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1
GENERAL
1.1
Scope of the manual
This manual provides essential information on L12 series
Neldisc® triple eccentric disc valves. Actuators and other
accessories are only discussed briefly. Refer to the individ-
ual manuals for further information on their installation,
operation and maintenance.
1.2
Valve construction
L12 series valve is a wafer type metal seated, full bore triple
eccentric disc valve. The valve body is one-part in sizes DN
80–600 and the sizes DN 700–1400 have a bolted clamp
ring.
The disc is elliptical and has a triple eccentric mounting.
When the valve is closed, the elliptical disc at the major axis
displaces the seat ring outward, causing the seat ring to
contact the disc at the minor axis. When the valve is
opened, the contact is released and the seat ring returns to
its original circular shape (see Fig. 1).
The disc is fitted to shafts with pins and there are no holes
through the disc.
Construction details of individual valves are included in the
type code shown on the valve identification plate. To inter-
pret the type code, please refer to Section 11.
The valve operates both in control and shut-off applica-
tions.
1.3
Valve markings
Body markings are cast on the body. The valve also has an
identification plate attached to it (see Fig. 2).
Identification plate markings:
1.
Body material
2.
Shaft material
3.
Trim material
4.
Seat material
5.
Maximum operating temperature
6.
Minimum operating temperature
7.
Maximum shut-off pressure differential
8.
Type designation
9.
Valve manufacturing parts list no.
10.
Pressure class
NOTE:
Selection and use of the valve in a specific application
requires close consideration of detailed aspects. Due to
the nature of the product, this manual cannot cover all the
individual situations that may occur when the valve is
used.
If you are uncertain about use of the valve or its suitability
for your intended purpose, please contact Metso for more
information.
Fig. 1
Construction of a triple eccentric disc valve
Fig. 2
Identification plate
BODY
TRIM
SHAFT
SEAT
TYPE
RATING
No.
t max.
t min.
ps
AT T E N T I O N : R E A D I N S T R U C T I O N S B E F O R E I N S TA L L AT I O N O R S E R V I C I N G. C O N TAC T M E T S O AU TO M AT I O N F O R C O P Y.
M a d e by M e t s o Fl o w C o n t ro l
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Summary of Contents for L12 Series
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