Portable siphon apparatus for removing concentrations of liquid from a gas pipeline

An apparatus for removing concentrations of liquid from a natural gas pipeline comprising a tap valve mounted on the pipeline at the upper portion thereof so as to be in communication with the interior of the pipeline. A siphon apparatus is removably mounted on the tap valve and includes a siphon pipe which is vertically movably mounted with respect to the tap valve. The siphon pipe is vertically movable from an upper position wherein the lower end of the siphon pipe is positioned above the tap valve to a lower position wherein the siphon pipe extends through the tap valve so that the lower end of the siphon pipe is positioned at the bottom interior of the pipeline. A discharge pipe extends from the siphon pipe and is in communication with a liquid holding tank. A siphon valve is imposed in the discharge pipe to permit the selective removal of the liquid from the pipeline.

BACKGROUND OF THE INVENTION 
This invention relates to a portable siphon apparatus which may be used to 
remove concentrations of liquid from a natural gas pipeline. 
A problem encountered in the transportation of natural gas through 
gathering and carrier pipelines is that liquid tends to concentrate in the 
"low spots" or sags in the pipeline. Collection of liquids in gathering 
system pipelines has always been a problem. In recent years it has become 
progressively worse since greater production demands and declining 
reservoir pressure have caused the producing formations to yield water at 
an ever increasing rate. Liquid removal equipment at well heads may not 
exist, or if it does, it may become over-loaded or fail to operate 
properly. Liquids are carried into the pipeline system where it condenses 
and separates from the natural gas stream and collects in the low places 
between hills, at stream undercrossings, or where the pipeline is buried 
deep in order to cross highways or railroads. 
Liquid concentrations in gathering systems seriously restricts the flow of 
gases and causes back pressures to be built against the feeding wells with 
consequent loss of well production. Liquid concentrations affect gathering 
compressors thereby causing waste of fuel and horsepower. Liquids moving 
through gas compressors cause excessive wear thereby increasing down time 
and maintaincost. During winter months when production is ordinarily most 
needed, the pipeline may freeze off completely and production from an 
entire subsystem may be lost. Such pipeline freezes are extremely 
difficult to locate and clear and usually happen at a time when weather 
and work conditions are less than desirable. 
In the past, to clear a section of pipeline of liquid, blowdowns on either 
end of a section were opened and the line was blown long and hard to the 
atmosphere. Large volumes of gas were wasted in addition to salt water and 
petroleum liquids being blown onto the land. 
Therefore, it is a principal object of the invention to provide an improved 
apparatus for removing liquids from natural gas pipelines. 
A still further object of the invention is to provide a portable siphon 
apparatus which may be used in combination with valves mounted at low 
spots or sags in the pipeline to remove liquids from the pipeline. 
A still further object of the invention is to provide a portable siphon 
apparatus for removing liquids from pipelines which does not require that 
the line be taken out of service. 
A still further object of the invention is to provide a portable siphon 
apparatus which may be used to remove liquids from pipelines wherein the 
liquids are not blown into the atmosphere. 
A still further object of the invention is to provide a portable siphon 
apparatus for removing liquids from natural gas pipelines without 
undesirable gas loss. 
A still further object of the invention is to provide a siphon apparatus 
for removing liquids from natural gas pipelines which is economical of 
manufacture and durable in use.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The numeral 10 refers generally to a natural gas carrier pipeline having 
liquid 12 which tends to concentrate in the low spots or sags in the 
pipeline. The presence of the liquid 12 in the pipeline restricts the flow 
of natural gas through the pipeline. The liquid 12 will also freeze during 
cold temperatures which can completely freeze off the pipeline. 
As stated, liquid inside a pipeline collects at low places. Pressure 
profiles taken during normal operating conditions will indicate the 
presence of liquid in the low places. The gas does not flow with 
sufficient velocity to carry the liquid over the top of hills or the like 
and must therefore pass through the liquid in the form of bubbles. After 
the pipeline has been excavated at the lowest point in a valley, the gas 
bubbles traveling through the liquid are audible and are detected with an 
electronic listening device such as a "Sonotec" instrument. At the lowest 
point in the valley, the pipeline is first excavated and a full-opening 
tap valve assembly 14 is installed on the pipeline in conventional 
fashion. As seen in the drawings, a reinforcing pad 16 is saddle welded to 
the pipeline so as to extend around the opening 18 which is formed in the 
pipeline 10 in conventional fashion using conventional tapping equipment. 
Nipple 18 is welded to pad 16 and extends upwardly therefrom. A 
full-opening tap valve 20 is welded to nipple 18 and is provided with a 
flange 22 at its upper end. The operation of the valve 20 is controlled by 
means of the stem portion 24 extending laterally therefrom. After the tap 
opening 19 has been formed in the pipe, the tap equipment is removed 
therefrom. 
When it is desired to remove the liquid 12 from the pipeline 10, the siphon 
apparatus 26 is removably secured to the valve assembly 14 as well be 
described in more detail hereinafter. Siphon apparatus generally comprises 
a support means 28 having a siphon pipe 30 vertically movably mounted 
thereon. More particularly, support means 28 comprises a blind flange 32 
which is bored and tapered and which is secured to flange 22 by a 
plurality of bolts 34 and nuts 36 in the manner illustrated in FIG. 2. 
Packing case or nipple 38 is welded to flange 32 and extends upwardly 
therefrom. The numeral 40 refers to a packing gland within nipple 38 which 
is positioned at the lower end of a packing follower sleeve 42 positioned 
in nipple 6. Flange 44 is welded to the upper end of case 38 and has four 
guide bolts 46 secured thereto by nuts 48 as illustrated in the drawings. 
Guide bolts 46 extend upwardly from flange 44 through flange 50 which is 
welded to the upper end of the packing follower sleeve 50. Nuts 52 are 
threadably mounted on guide bolts 46 above flange 50 for maintaining the 
flange 50 and sleeve 42 in position so that the lower end of the sleeve 42 
will be maintained in engagement with the packing gland 40. Siphon pipe 54 
is vertically movably received by the sleeve 42 and extends downwardly 
through valve 20, when valve 20 is open, so that the lower end thereof is 
received by the pipeline 10. A T-fitting 56 is secured to the upper end of 
pipe 54 and has discharge pipe 58 extending laterally therefrom. Discharge 
pipe 58 extends to a liquid holding tank and has a full opening ball valve 
60 enclosed therein. Plug 62 is secured to the upper end of T-fitting 56 
and has flange 62 welded thereto which is vertically movably mounted on 
the guide bolts 46. Adjustable stops 64 are mounted on the guide bolts 46 
to limit downward movement of the flange 17 and hence the siphon pipe 54 
to prevent the pipe 54 from engaging the pipeline. 
Capscrew 66 is mounted in the upper end of plug 62 and is held therein by 
set screw 68. Cap 70 is rotatably mounted on capscrew 66 as illustrated in 
the drawings and has a grease zerk fitting 72 provided thereon to enable 
grease to be inserted into the interior of the cap 70. The numeral 74 
refers to a double race thrust bearing which is positioned between the 
lower end of the cap 70 and the upper end of flange 62. A grease retainer 
76 in the form of a rubber boot embraces cap 70 and extends around the 
bearing 74 as illustrated. 
Feed screw 76 is welded to disc 78 which is welded to the upper end of cap 
70. Feed screw 76 extends upwardly through a feed screw nut 80 which is 
welded to the underside of flange 82 secured to the upper ends of guide 
bolts 46 by nuts 84. Screw handle 86 is secured to the upper end of screw 
76 by pen 88. 
In operation, the tap-valve assembly 14 is preferably mounted on the 
pipeline 10 at each sag or low spot previously described with the valve 20 
being normally closed. When it is desired to remove the liquid from the 
pipeline 10, the flange closing the upper end of the valve 20 is removed 
and the siphon apparatus 26 is mounted thereon by means of the bolts 34 
and nuts 36. Prior to mounting the siphon apparatus 26 on the valve 
assembly 14, screw 76 is rotated to move flange 62 upwardly towards the 
upper ends of the guide bolts 46 so that the lower end of the siphon pipe 
54 is positioned above valve 20 with sufficient clearance to allow valve 
20 to be closed. Valve 60 is initially closed as the siphon apparatus 26 
is secured to the valve assembly 14. After the siphon apparatus 26 has 
been secured to the valve assembly 14 and the discharge pipe 58 has been 
placed in communication with the holding tank, the valve 20 is opened and 
screw 76 is rotated by means of handle 86 so that siphon pipe 54 moves 
downwardly through the valve 20 and into the interior of the pipeline 10 
as illustrated. Preferably, the lower end of the siphon pipe 54 is beveled 
or tapered as illustrated. Also, it is recommended that the minimum of 
one-half inch clearance be maintained between the lower end of the siphon 
pipe and the bottom of the pipeline. 
From the description herein, it can be seen that pipe 54 does not rotate as 
it is being lowered into the pipeline due to the rotatable connection 
being provided between the screw 76 and the plug 62. Upon the siphon pipe 
54 being lowered to the proper position, valve 60 is then opened so that 
the pressure within the pipeline 10 causes the liquid 12 to be forced 
upwardly through the siphon 54 and outwardly through the discharge pipe 58 
to the holding tank. When the liquid has been blown from the pipeline 10, 
valve 60 is closed and the siphon pipe 54 is raised by means of the screw 
76 until the lower end of the siphon pipe is again positioned above valve 
20 with sufficient clearance to allow valve 20 to be closed. Valve 20 is 
then closed and valve 60 opened to relieve pressure. The siphon apparatus 
26 is then removed from the valve assembly 14. The siphon apparatus 26 may 
then be taken to the next location requiring the removal of liquids from 
the pipeline. 
Thus it can be seen that a novel portable siphon has been provided which 
permits the removal of liquid from a pipeline without the necessity of 
taking the line out of production. Additionally, it can be seen that a 
novel siphon apparatus has been provided which is safe to use under high 
pressure conditions and which prevents the liquid from being blown into 
the atmosphere. Thus it can be seen that the invention accomplishes at 
least all of the stated objectives.