US 5,484,174 AGranted

Pipe coupling and method of joining materials

AssigneeMie Horo Co., Ltd.

InventorsTaiji Gotoh, Hidetoshi Yamamoto, Kiyokazu Iwama, Kiyoshi Yamada

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Abstract

Pipe fittings for joining piping materials have a main body with a substantially equal diameter to that of the piping materials to be joined, an annular expanded portion formed at least at one end portion thereof and enlarged diameter portions on each side of the annular expanded portion. The piping materials are joined by inserting them into the pipe fittings and by pressing the outer enlarged diameter portion along the circumference at an end portion thereof to subject the enlarged diameter portion and the piping materials to plastic deformation. By virtue of recesses formed at the pressed portions, the pipe fittings and the piping materials are firmly fixed together. A tapered portion provided at the end of the pipe fittings effectively increases the slip-off checking force, and also the Joint can be perfectly sealed by the sealing material received in the internal space of the annular expanded portion, having been deformed by the application of pressing. Crevice corrosion can completely be prevented since an adequate clearance is defined between the non-pressed enlarged diameter portion and the piping materials inserted into the pipe fittings.

Claims17

Dependent claims

A pipe fitting for joining together piping material, the pipe fitting (2) comprising:

a substantially cylindrical main body portion (3) having an inner diameter which is substantially the same as an inner diameter of said piping material (1) to be joined;
first and second cylindrical portions (4, 6) extending from said main body portion (3) in a given direction, said first and second portions (4, 6) each having an inner diameter larger than that of said main body portion (3), said second portion (6) being joined to said main body portion (3) at a distal end of said second portion (6);
an outwardly extending annular portion (5) defining an annular space for receiving therein a sealing material (8), said annular portion being located between said first and second portions (4, 6) and extending outwardly relative to said first and second portions (4, 6);
said second portion (6) having a clearance (9) of not less than 100 .mu.m between the outer surface of said piping material (1) to be joined and the inner surface of said second portion (6), to prevent crevice corrosion at said inner surface of said second portion (6) and at the outer surface of said piping material (1) to be joined;
and wherein:
said second portion (6) has a length (L1) as measured from said annular portion (5) to the distal end of said second portion (6);
said first portion (4) has a length such that a recess (13) formed therein is at a distance (L2) measured from said annular portion (5), wherein said length (L1) is substantially equal to said distance (L2);
said first portion (4) has a main substantially cylindrical portion and an outwardly tapered annular portion (7) formed at a distal end portion of said first portion (4);
and
said tapered annular portion (7) has a degree of taper such that an annular entrance clearance is formed between an internal surface of the distal end of the tapered portion (7) and an external surface of the piping material (1) to be joined;
and
said annular entrance clearance is substantially equal to a wall thickness of the pipe fitting.

9 more elements

A combination of a piping material and a pipe fitting for joining to the piping material, the combination comprising:

an elongated cylindrical piping material (1) and
a pipe fitting (2) comprising:
a substantially cylindrical main body portion (3) having an inner diameter which is substantially the same as an inner diameter of said piping material (1);
first and second cylindrical portions (4, 6) extending from said main body portion (3) in a given direction, said first and second portions (4, 6) each having an inner diameter larger than that of said main body portion (3), said second portion (6) being joined to said main body portion (3) at a distal end of said second portion (6);
an outwardly extending annular portion (5) defining an annular space for receiving therein a sealing material (8), said annular portion being located between said first and second portions (4, 6) and extending outwardly relative to said first and second portions (4, 6);
said second portion (6) having a clearance (9) of not less than 100 .mu.m between an outer surface of said piping material (1) to be joined and the inner surface of said second portion (6), to prevent crevice corrosion at said inner surface of said second portion (6) and at the outer surface of said piping material (1);
and wherein:
said second portion (6) has a length (L1) as measured from said annular portion (5) to the distal end of said second portion (6);
said first portion (4) has a length such that a recess (13) formed therein is at a distance (L2) measured from said annular portion (5), wherein said length (L1) is substantially equal to said distance (L2);
said first portion (4) has a main substantially cylindrical portion and an outwardly tapered annular portion (7) formed at a distal end portion of said first portion;
and
said tapered annular portion (7) has a degree of taper such that an annular entrance clearance is formed between an internal surface of the distal end of the tapered portion (7) and an external surface of the piping material (1) to be joined;
and
said annular entrance clearance is substantially equal to a wall thickness of the pipe fitting.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/465,208Filed 3 Jun 1994
Priority: JP 63-17439313 Jul 1988
Granted: 16 Jan 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

F16L 13/142
By crimping or rolling from the outside: with a sealing element inserted into the female part before crimping or rolling
B21D 39/046
Of tubes with tubes; of tubes with rods: connecting tubes to tube-like fittings
F16L 13/161
The pipe joint consisting of overlapping extremities having mutually co-operating collars: the pipe or collar being deformed by crimping or rolling
Y10T 29/49913
Securing cup or tube between axially extending concentric annuli: by constricting outer annulus