Tomoe 304YA, Instruction Manual

Page: 12 / 29

11
3. 4 Installation Precautions
(Continued)
10) Align the primary side pipe with the secondary side pipe properly and make sure that the
pipes are parallel and there is no distortion. If the alignment is not proper, external leakage,
seat leakage, or faulty operation may occur.
11) When installing a non-return valve, pump, or flexible joint with this product, insert a short pipe
between the part and the product. Not inserting a short pipe may cause the disc to make con-
tact with the other device during operation, resulting in faulty operation, external leakage, and
seat leakage. Refer to section
6. 1 for protruding dimensions of the disc.
12) Connect this product to the primary side of a bent pipe (elbow, tee). If the product is connected
to the secondary side by necessity, secure a straight pipe distance of 5 times or more of the
pipe diameter from the bent pipe. In addition, the product should be positioned so that the flow
velocities at the right and left sides of the shaft are the same. [Fig.-7]
If the product is closely connected to the secondary side of a bent pipe, etc., flow velocity and
pressure distribution cause unbalanced torque on the disc, which may increase the operating
force or have an adverse effect on the performance and service life of the product.
13) When this product is connected to the secondary side of a control valve, pump outlet, or re-
ducer, secure a straight pipe distance of 5 times or more of the pipe diameter. In addition, the
valve should be positioned so that the flow velocities at the right and left sides of the shaft are
the same. [Fig.-7]
14) When replacing a valve with a long face-to-face dimension (e.g. gate valve, globe valve, ball
valve) with this product, you must insert a short pipe and adjust the total length of the short
pipe and the face-to-face dimension of this product to the face-to-face dimension of the origi-
nal valve flange. Use the equation below when making a short pipe. [Fig.-11]
15) After piping work is completed, set this product to the full-open positon and check that the disc does
not make contact with the inner surface of the flange.
16) Also, insulate around the valve body when the valve will be used with high-temperature fluids that
exceed 60°C.
Poor centering alignment
of the pipes
Poor parallel
alignment
Distortion
[Fig.-10]
<Table-4>
Length of short pipe
L2 = L1 – L - t
mm
L2 : Length of short pipe mm
L1 : Face-to-face dimension of
existing valve
mm
L : Face-to-face dimension of
TOMOE butterfly valve
mm
t : Thickness of gasket packing mm
[Fig.-11]
L L2
L1
Butterfly valve
Short pipe Pipe
Piping gasket
Existing valve
L1 t t
t
t
t
Piping gasket
Pipe