[0001] Free-flow valves may be obtained by casting (in different materials) or by means
of electric welded sheet metal or tube, generally made of stainless steel, as shown
in Fig. 1 attached hereto.
[0002] The sheet-metal or tube type comprises a fluid inlet tube (1), Fig. 1, a central
body (2), Fig. 1, presenting a 45° inclination, with upper flange sealing seat to
secure either a manual or a pneumatic control, and a fluid outlet tube (3), Fig. 1.
[0003] The description of the process to be followed to obtain said upper flange sealing
seat may be overlooked, being it similar in all cases; currently, said central body
(2), Fig. 1, is obtained by cutting (by means of shears, plasma, etc.) into the sheet
metal the shaped hole whereon tube (3), Fig. 1, is to be welded.
[0004] Next, the sheet metal is bowed to form a tube and then the joint is welded manually.
Or else, a tube may be used in place of metal sheet, and said shaped hole may be cut
therein, by means of shears or plasma, with a 45° inclination. In the latter case,
more complex tooling is necessary to work on tube, as compared to sheet metal.
[0005] To obtain tube (3), Fig. 1, the sheet metal is shaped, so that the inclined end may
fit the shape of the hole of body (2), Fig. 1, it is then bowed to form a tube and
then the joint is manually welded thereon. Finally, body (2), Fig. 1, is joined to
tube (3), Fig. 1, by means of manual welding following the complex intersection profile
of the two inclined cylindrical shapes which are also of different dimensions.
[0006] A trimming and chamfering operation is to be carried out inside body (2), Fig. 1,
next to the joint with tube (3), Fig. 1, to eliminate flash, sharp edges and uneveness.
[0007] Forming of tube (1), Fig. 1, is carried out by cutting, with a 45° inclination, a
tube presenting suitable diameter, which is then welded on to body (2), Fig. 1.
[0008] Aim of the present invention is the innovating method for obtaining and assembling
the structure of the valve body in issue.
[0009] Said aim being achieved by the present invention in that is relates to a method for
obtaining a valve body as described in Claim 1.
[0010] The present invention will be now described with reference to the attached drawings,
in which:
Fig. 1 shows the conventional solution;
Fig. 2 shows the innovating solution subject of the present invention; and
Fig. 3 shows the method for obtaining the present invention.
[0011] To build body 2, Fig. 2, after cutting a suitable initial hole into a tube, the hole,
with a 45° inclination, is obtained, by pressing, along with relevant bent portion
4 (Fig. 2).
[0012] Pressing is carried out by pushing punch A (Fig. 3) through the hole initially cut
into body 2 (Fig. 3), the latter being inserted into dies B and C (Fig. 3).
[0013] The same result may be obtained by means of other pressing methods, as well.
[0014] Said bent portion 4, after a quick flattening of its edges 5 (Fig. 2), is ready to
be placed coaxially to and welded by automatic welding with tube 3, Fig. 2.
[0015] A tube 1 is subsequently cut in an oblique manner with respect to said tube axis
and is welded with a portion of the perimeter of body 2.
[0016] On the grounds of the foregoing, working of tube 3 is clearly made easier, in that
it starts directly from the tube which, after being cut with a 45° inclination, is
ready to be welded by automatic welding on body 2, Fig. 2. The same, easy procedure
can be followed in connection with tube 1, Fig. 2, as well.
[0017] A further advantage arising from said bent portion is represented by radius 6, Fig.
2, which forms automatically between said bent portion and said body, allowing for
a more regular flow of the fluid; and, therefore, a smaller loss of pressure in respect
to the conventional solution.
[0018] Moreover, either inner trimming and chamfering operations are no longer necessary.
[0019] A further advantage of the present invention is represented by the evident improvement,
from the point of view of both aesthetics and operation, arising from pressing and
automatic welding.
1. A method for obtaining a valve body, characterized in that it comprises the following
stages:
cutting of an initial hole into the wall of a first tube (2);
widening, by pressing, of said initial hole thus obtaining a tubular bent portion
(4) extending outwards from first tube (2);
cutting of a second tube (3), in an oblique manner with respect to the axis of
same tube (3);
connection of said first (2) and second (3) tube with said tubular bent portion
(4), coaxial to said second tube (3);
welding of one end edge (5) of said bent portion (4) with an oblique end edge of
said second tube (3).
2. A method as claimed in Claim 1, characterized in that it comprises one stage, during
which said edge (5) of said bent portion (4) is flattened.
3. A method as claimed in either Claim 1 or 2, characterized in that it comprises one
stage, during which a third tube (1) is cut in an oblique manner with respect to the
axis of same tube (1); and
said third tube (1) being subsequently welded on to an end portion of said first
tube (2).
4. A valve body, characterized in that it comprises:
a first tube (2) presenting a tubular bent portion (4) extending outwards from
same tube;
a second tube (3), coaxial to said tubular bent portion (4); and
an end edge (5) of said bent portion (4) being welded to an oblique edge of said
second tube (3).
5. A valve body as claimed in Claim 4, characterized in that said tubular bent portion
(4) presents an axis forming an oblique angle with the axis of said first tube (2).
6. A valve body as claimed in Claim 5, characterized in that said tubular bent portion
(4) presents an axis having a 45° inclination with respect to the axis of said first
tube (2).
7. A valve body as claimed in any one of Claims 4 to 6, characterized in that it comprises
a third tube (1), welded to an end portion of said first tube (2).