Hydraulic dredge pipeline coupling

A smooth bore, self-aligning connection for pipes of the type used in hydraulic dredging. In this connection, the spigot end of one pipe contacts metal to metal at the bell end of the other pipe. A packing gland is defined outwardly of the contacting pipe ends by a positioning ring toe and an annular ring of the bell. A third annular ring on the bell end engages a stepped ring on the spigot end to align the pipes longitudinally as well as radially. A locking ring which is threadedly adjustable engages a skirt depending from a fourth annular ring formed on the bell to lock the spigot end of the pipe to the bell end. The bell and spigot connection of this invention is also adaptable to a pontoon pipe having a flexible reinforced rubber hose section between the spigot and bell ends of a pipe.

SUMMARY AND BACKGROUND OF THE INVENTION 
The invention is concerned with a coupling for pipe of the type that is 
used in the hydraulic dredging industry and particularly with pipe that is 
used as dredge shore pipe and pontoon pipe. 
The provision of adequate tension, compression and torsion strength in 
couplings of the steel pipe used for pontoon pipe and dredge shore pipe is 
important because of the high stresses applied to couplings of this type 
of pipe in normal use. For example, pontoon pipe which extends from the 
floating dredge to the shore or a spoil barge is subjected continuously to 
forces of wind and current, and to the forces which are applied when the 
pontoon pipe is moved under tow when it is being relocated. Flexibility in 
pontoon pipe lines is presently obtained through the use of ball joints or 
rubber sleeves between pipe lengths. Ball joints are in common use today 
but have the real disadvantage of extremely poor hydraulic 
characteristics. Slurry flow in a pipe travels at a certain speed or 
velocity. Since the inside of the ball necessarily has a larger 
cross-sectional area than the pipe, the velocity of flow is suddenly 
reduced when slurry enters the ball. When the slurry leaves the ball, it 
passes through the ball exit which is the diameter of the pipe. Upon 
leaving the ball, the slurry enters the bell when it experiences a second 
expansion and drop in velocity. Upon leaving the bell, the slurry enters 
the pipe, which has a smaller inside diameter than that of the bell. The 
result is that a ball joint is a consumer of power. A purpose of my 
invention is to reduce this consumption of power by using a smooth bore, 
flexible pontoon pipe connection. The ball joint is competent in tension. 
The use of rubber sleeves to provide flexibility between pontoon pipes is 
not extensive because rubber sleeves cannot withstand tension nor can they 
withstand bending. My pontoon pipe provides both flexibility and 
resistance to separation due to tensile forces. 
The shore pipe which leads from the pontoon pipe to the spoil area is often 
laid over rugged ground and therefore may extend up and down hills. 
Movement in the couplings of shore pipe results in leakage and can even 
culminate in separation of the pipe. Further, the couplings of such pipe 
are stressed by the pulsations of the slurries of dredged material that 
are forced through the pipe by the hydraulic pump of the dredge. 
Previous couplings for shore dredging pipe have been concerned with the 
prevention of leakage but have not attempted to form a coupling that would 
prevent separation of the pipe caused by the large tension and torsion 
forces that are experienced during dredging operations. The couplings that 
have provided a mechanical connection between shore pipes have not been 
sufficiently strong to resist the forces normally encountered in dredge 
pipeline operations. As a result, auxiliary tension resisting devices such 
as strapping have been used between the couplings of shore pipe to resist 
separation. 
An object of this invention is a bell and spigot connection for pipe such 
as dredging pipe that provides a smooth bore, self-alignment of connecting 
pipes and a minimum, if any, gap between the pipes to reduce turbulence 
and friction loss. 
Another object of this invention is a bell and spigot connection for 
hydraulic dredging pipe which provides a strong physical connection 
against separation and breakage due to tension, compression and torsion 
forces, i.e., a physical connection that is almost as strong as that of 
the pipe itself. 
Another object of this invention is a bell and spigot connection for 
hydraulic pipe in which the packing is trapped between metal-to-metal 
portions of the bell and spigot ends of the pipes. 
Another object of this invention is a bell and spigot connection having an 
outer metal-to-metal contact between the bell and a stepped ring on the 
spigot to absorb the axial loading for compression and tension forces, an 
intermediate sleeve to define a packing gland with the toe of the stepped 
ring and an inner sleeve to align with the spigot of the pipe to eliminate 
any gap which would cause turbulence. 
Another object of this invention is a bell and spigot connection for pipes 
that can be assembled by welding together easily formed parts and which 
does not require any elaborate castings or machined parts for the 
connection. 
Another object of this invention is a rubber sleeve, flexible pontoon pipe 
connection which replaces the conventional machined ball joint for 
connecting pontoon pipes. 
Other objects ma be found in the following specification, claims and 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 3 of the drawings is a partial, cross-sectional view of the assembled 
pipe connection 11 of this invention. The connection includes a first pipe 
13 having a spigot end wall 15. The first pipe has an internal surface 17 
and an external surface 19. The second pipe 21 has an end wall 23 which is 
angled, an interior surface 25 and an exterior surface 27. 
A fabricated bell 31 is attached to the angled end wall 23 of the second 
pipe. The bell receives the spigot of the first pipe to form the 
connection 11. As is conventional, the first and second pipes and all of 
the pipes in the dredge pipeline, whether shore pipe or pontoon pipe, are 
identical in that each has a spigot end and a bell end of the type 
described herein. However, some of the pontoon pipes are equipped with 
flexible sleeve portions as will be described hereinafter. 
The bell 31 includes a first annular ring 33 having essentially the same 
interior diameter as that of the second pipe 21, and a slightly larger 
thickness than that of the first pipe, with the first annular ring welded 
to the angled end wall 23 of the second piece of pipe. The first annular 
ring has an end wall 35 which contacts the spigot end wall 15 of the first 
pipe when the connection is made to eliminate, if possible, any gap 
between the two pieces of pipe. 
A second annular ring 39 telescopes over and is welded to the first annular 
ring 33, with the second annular ring extending outwardly beyond the end 
wall 35 of the first annular ring and having its own end wall 41. A third 
annular ring 45 telescopes over and is welded to the second annular ring 
39 and extends longitudinally outwardly beyond said second annular ring a 
much greater distance than the second annular ring extends outwardly 
beyond the first annular ring. The third annular ring 45 has an end wall 
47. The distance between the end wall 47 of the third annular ring 45 and 
the end wall 35 of the first annular ring 33 of the bell 31 is predefined 
so that the spigot end wall 15 of the first pipe 13 will come in contact 
with the end wall 35 of the first annular ring 33 of the second pipe 21 
without leaving a gap which could cause turbulence and friction loss. 
A fourth annular ring 51 of greater longitudinal extent than the other 
annular rings telescopes over and is spaced radially from the third 
annular ring 45. The fourth annular ring is attached to the third annular 
ring by sets of arcuately-located spacers 53 which are welded to the third 
and fourth annular rings. Located at the outer end of the fourth annular 
ring is an inwardly-projecting lip 55 having arcuately-spaced notches 57 
formed therein. The lip extends inwardly but terminates short of the third 
annular ring 45. 
Welded to the exterior surface 19 of the first pipe 13, at a location 
inwardly of the spigot end wall 15, is a stepped ring 61. The stepped ring 
has an outer radially-extending annular shoulder 63 facing the spigot end 
wall 15. This shoulder is located a predefined distance from the spigot 
end wall 15 equal to the distance between the end wall 47 of the third 
annular ring 45 of the bell connection and the end wall 35 of the first 
annular ring 33 of tis connection. This dimensioning positions the spigot 
end wall 15 in contact with the end wall 35 of the bell connection to 
eliminate any gap between the first and second pipes. 
An inner radially-extending annular shoulder 65 (sometimes referred to as a 
toe) is located to align with and be spaced from the end wall 41 of the 
second annular ring 39 to form a packing gland 67 there between the end 
wall 41 and the toe 65. A packing material 69 is located in this packing 
gland and is compressed between the annular shoulder 65 and the end wall 
41 to prevent leakage through the connection. Also formed on the stepped 
ring 61 is a longitudinally-extending annular shoulder 71 of a predefined 
diameter which extends between the radially-extending shoulders 63 and 65. 
The longitudinally-extending shoulder 71 engage the inner surface of the 
third annular ring 45 to align the first pipe 13 in the bell connection 31 
of the second pipe 21. 
A locking ring 75 is slidably mounted on the outer surface 19 of the first 
pipe 13 on the side of the stepped ring 61 away from the spigot end wall 
15. A bead 77 is welded to the outer surface 19 of the pipe 13 to prevent 
the locking ring from sliding away from the stepped ring 61. A plurality 
of turn screws 79 extend through the locking ring to engage the stepped 
ring 61. The locking ring 75 has lugs 81 which fit through the notches 57 
in the lip 55 attached to the end of the fourth annular ring of the bell 
connection when the spigot end of the first pipe is inserted in the bell 
end of the second pipe. The turn screws are engaged with the locking ring 
61 to force the lugs 81 against the lip 55 to tighten the connection 
between the first and second pipes. 
A first pipe 13, such as the pipe previously described, will not only have 
a spigot end wall 15 but will also have a fabricated bell 31 at the 
opposite end for connection to the similar pipes. However, such a pipe 13 
may also be made into a pontoon pipe connection since the pipes 13 and 21, 
when they are extended over water, need a flexible connection to absorb 
the action of waves, wind, etc. Such a pontoon pipe connection is shown in 
FIGS. 1 and 2 of the drawings. To construct a pontoon pipe connection 91, 
a pipe such as a first pipe 13 or a second pip 21 is cut intermediate its 
spigot end wall 15 and its fabricated bell 31, providing a spigot end stub 
portion 93 and a bell end stub portion 95. The two stub portions are then 
seated in opposite ends of a reinforced rubber hose 97. A suitable 
reinforced rubber hose may be obtained from many large diameter hose 
manufacturers. The rubber hose has an internal surface 99 with entrance 
sections 101 and 103 at opposite ends thereof of larger diameter to 
receive the stub portions 93 and 95 of a pipe, respectively, so that the 
inner surfaces of the stub portions of the pipe are aligned with the inner 
surface 99 of the reinforced rubber pipe to eliminate turbulence and 
friction loss. The entrance portions of the reinforced rubber hose may be 
clamped to attach the hose to the spigot end stub portion and bell end 
stub portion of the pipe, but the clamps are not shown for clarity of 
illustration. 
In order to prevent separation of the spigot end stub portion 93 and the 
bell end stub portion 95 from the reinforced rubber hose section 97 due to 
tension forces caused by wave action, wind, towing action, etc., snubbing 
cables 105 are provided. In this example, four snubbing cables, each 
located 90 degrees apart around the rubber hose, are used to limit the 
degree of deflection of the hose laterally and horizontally to prevent the 
hose from crimping. As is conventional, the snubbing cables 105 are 
anchored to ears 109, welded on the spigot end and bell end stub portions 
93 and 95, respectively. 
FIG. 1 of the drawings shows the pontoon pipe connection in its aligned or 
untwisted position, while FIG. 2 of the drawings shows it in a bent 
position in which the snubbing cables 105 prevent pull apart of the 
connection and also limit the amount of bending of the reinforced rubber 
pipe 97 to prevent crimping on the side which is on the inside of the bend 
.