Fluid sample apparatus featuring integral construction with a motor driven sampling system

Abstract

A fluid motor integrally constructed on an elongate body enables periodic fluid sampling. This device affixes to a pipeline by a threaded connection which positions an inlet in the pipeline for sample removal; the sample flows to a sample bite removal valve which is motor operated to obtain periodic simple bits. Pressure step up or down is achieved in a sample pressure isolation system having a check valve function. This enables storage at any pressure.

Description

a rigid relatively narrow passage 71 which opens to a valve seat 72 defined by a resilient O-ring. There is a tapered needle valve element 73 positioned against the seat. It incorporates a needle valve tip for guidance, and it is forced open by gas flow against the valve element 73. The needle valve is urged to a closed position by resilient spring 74. The spring is captured below a spring mechanism, this mechanism including a surrounding insert 75, a captured orifice fitting 76, and suitable seals to prevent leakage around these components. Gas flows from the chamber 42 through the small orifice 71. It flows through the needle valve and past the needle valve. It flows through a small orifice passage 77 drilled in the orifice fitting 76. It is delivered through the bottom of this passage and out that opening. However, fluid is not permitted to flow because there is a pressure set check valve to be overcome. This pressure set check valve is made dependent on line pressure. Specifically, line pressure is introduced from the supply passage 22 through a lateral line 78, and below a plunger 79. The plunger 79 supports a plug 80 which blocks flow out through the passage 77. The plug 80 is smaller than the passage and hence, any gas flow escaping that contact flows downwardly and into the port 81 when contact between plug 80 and fitting 76 is broken. The port 81 includes the appropriate fittings 82 and connects through the outlet line 83 to a sample storage container. The plunger 79 is forced upwardly by a bias spring 84 which is of sufficient strength to force the plug 80 upwardly. However, plug movement is controlled primarily by the cross-sectional area of the plunger 79 and pressure which is exposed to it. Representative pressure levels will be given hereinafter.

Consider a typical situation in operation. Assume that the sampler 70 is installed on a natural gas line at 1,000 psi. Fluid flows from left to right as viewed in FIG. 2. The inlet means 15 draws in fluid flow, and it flows into the inlet passage 22 assuming the valve handle 20 has been operated to open the valve 18. This fluid flows to the plunger 40. It is captured in the passage 42 when the plunger is operated downwardly. Surplus fluid is delivered away from the plunger. One outlet is through the line 29 which flows to the timed controller 30 which times application of fluid to the fluid motor at the top end which operates in the same fashion as shown in FIG. 1 of the drawings. That is, the plunger 40 is driven downwardly by the piston, and compression of the captured gas occurs in the passage 42. As can be seen in FIG. 2, fluid or gas from the pipeline and rigid sample chamber 42 is employed (through passage 38, line 29, and controller 30) to actuate plunger 40, and the volume of gas sampled after actuation of plunger 40 is fresher or more representative of that flowing in the pipeline at the time of the sample.

The gas is compressed, forced downwardly, and the flows past the needle valve. It flows into the small passage 77 through the orifice insert 76. When this pressure is sufficiently high, it will force the plug 80 slightly downwardly so that gas flows around the plug 80. Gas flows through the outlet port or passage 81 into the fitting 82 and through the line 83 for delivery to the sample storage chamber which is not shown. The gas so stored is recovered for sample testing purposes.

Consider representative pressures which might occur in the sampler 70. The passage 78 is provided with gas at line pressure or 1,000 psi in this example. It is applied below the plunger 79. The plunger 79 has a ratio of area to the plug 80 of about 2:1 and provides multiplication of approximately two fold in that event. That is, gas samples delivered through the passage 77 must exceed approximately two fold line pressure. In other words, the plug 80 will not open until pressure bearing against it at the top end is in excess of about 2,000 psi in this example. Gas flows upwardly through the supply passage 22 and is delivered into the chamber 42. When the plunger 40 moves downwardly into the seal 41, pressure rises in the chamber 42. This pressure rise is observed therebelow in the passage 77. When that pressure becomes sufficient, the plug 80 is forced backwardly, opening slightly and gas flows into the port 81. Fluid then flows while exceeding this representative pressure. That is, the gas that is delivered through the outlet line 83 is compressed to a sufficient pressure that is forces open the tapered needle valve 73, and also flows past the plug 80.

Assume that the storage container for the sample is maintained at a pressure which is low. In that event, the sample is simply delivered in regular fashion into that storage vessel. If however, the back pressure of the storage vessel is much greater than the line pressure, that does not pose any problem either. Sample cannot escape back into the equipment because there is a check valve at the valve 73. Accordingly, the pressure on the compressible gas is raised sufficiently high that it will overcome practically any back pressure at the storage container. Moreover, pressure is isolated between strokes so that the storage container does not bleed through the sampling valve just described.

Consider proportioning of the present apparatus. Sample again is captured in the range of about one part in 10⁵ up to about one part in 10⁹. Obviously, these are subject to scale factors and can be varied to a desired output sampling rate.

The samplers 10 and 70 utilize the same basic structural components. They both terminate at a remote end which incorporates a fluid motor. In both instances, the motor is preferably single acting with a return spring. That is, fluid pressure from the pipeline is used to drive the piston. This avoids the necessity of providing a remote fluid supply at a remote location. Just as importantly, pipeline pressure is not a limitation on the operation of the fluid motor because it is provided with greater cross-sectional area so that even a low pipeline pressure system can provide sample against a high back pressure storage device.

While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow:

Claims

1. An assembly for obtaining a fluid sample from a pressurized pipeline comprising:

(a) an elongate body having

(i) a first end formed to connect to a pipeline to position a pressurized fluid inlet probe in the pipeline to receive pressurized fluid;

(ii) a central body portion connected to said first end; and

(iii) a second end deployed from said first end;

(b) a fluid flow inlet line extending through said elongate body and connected from said fluid inlet probe to deliver a flow of fluid;

(c) fluid sampling means connected to said fluid flow inlet line to deliver fluid thereto such that fluid is delivered to said fluid sampling means in a volume in excess of said sample, said sampling means periodically removing fluid from said fluid flow inlet line;

(d) said sampling means periodically removing fluid from said fluid flow line;

(e) outlet means connected to said sampling means for delivery of a fluid sample without regard to whether the pressure in the pipeline exceeds that in a fluid sample vessel or the pressure in the fluid sample vessel exceeds that in the pipeline;

(f) (e) check valve means cooperative with said outlet means to enable fluid to flow through said outlet means to overcome back pressure encountered by fluid flow;

(g) (f) said fluid sampling means including a rigid sample chamber connecting means connecting said fluid sampleing means and check valve means; and

(h) (g) motor means in said body for operating said sampling means to direct fluid through said outlet means, said motor means being in fluid communication with the pipeline through said fluid sampling means, wherein, upon actuation of said motor means and said fluid sampling means, a fresh sample of pressurized fluid from the pipeline is taken.

2. The assembly of claim 1 wherein said fluid sampling means comprises:

(a) sample chamber means for receiving pressurized fluid therein;

(b) a movable plunger sealingly received in said rigid sample chamber means;

(c) (b) means connecting said motor means to said plunger to reciprocate said plunger through a first position to allow fluid in said chamber means, and reciprocate said plunger to a second position to force fluid through said check valve means; and

(d) (c) said motor means forms sufficient pressure to open said check valve means and also overcome any back pressure encountered by fluid flow from said outlet means.

3. The assembly of claim 1 wherein said elongate body is formed by:

(a) a lower end portion having a downwardly extending probe for insertion into a pipeline, and said probe extends from a threaded fitting cooperatively connecting to a mating fitting on the pipeline;

(b) an intermediate portion supporting said outlet means and said check valve means; and

(c) an upper end portion comprising said second end and supporting said motor means wherein said upper end portion is joined with and connected to said intermediate portion to align sad body portions for joinder in an integrated assembly.

4. The assembly of claim 3 further including at least one fluid flow passages extending through each of said body portions for controlled fluid flow from said fluid inlet and to said outlet means as controlled by said fluid sampling means and said check valve means. 5. The assembly of claim 4 wherein said passages include:

(a) an inlet flow passage to said fluid sampling means;

(b) an outlet flow passage from said fluid sampling means for delivery of surplus fluid not sampled by said sampling means, said outlet flow passage

having a separate outlet for the surplus fluid.6. The assembly of claim 5 4 wherein said outlet flow passage is directed to said lower end body portion and said outlet thereof returns surplus fluid

into the pipeline. 7. The assembly of claim 3 wherein said motor means comprises a piston in a cylinder defining a fluid receiving compression chamber, and said piston is connected to a plunger moveably positioned in a chamber to reciprocate, said plunger and chamber comprising said fluid

sampling means. 8. The assembly of claim 1 wherein said fluid sampling means and said check valve means comprise:

(a) a reciprocating plunger;

(b) a fluid receiving chamber for receiving fluid therein, said chamber further receiving said plunger to force fluid out of said chamber;

(c) a passage for pressurized fluid from said chamber;

(d) a valve seat fluidly connected to said passage;

(e) a valve element cooperative with said valve seat to close said passage to fluid flow; and

(f) spring means bearing against said valve element to provide a force overcome by fluid pressure on operation of said plunger, said spring means

otherwise closing said valve element. 9. The assembly of claim 8 wherein

said valve element is a needle valve. 10. The assembly of claim 9 including an additional serially connected supply pressure operated valve

means closing as a function of pipeline pressure. 11. The assembly of claim 8 wherein said valve element is a resilient plug larger in size than

said valve seat and is constructed to fully close off fluid flow. 12. The assembly of claim 11 wherein said resilient plug is supported in a

surrounding metal ring. 13. The assembly of claim 12 wherein said ring includes a connected stem mounting said resilient plug for reciprocation.

14. An assembly for obtaining a fluid sample from a pressurized pipeline comprising:

(a) an elongate body having

(i) a first end formed to connect to a pipeline to position a pressurized fluid inlet probe in the pipeline to receive pressurized fluid;

(ii) a central body portion connected to said first end; and

(iii) a second end deployed generally opposite from said first end;

(b) a fluid inlet passage extending from said pressurized fluid inlet probe and through said elongate body to deliver fluid from said pipeline in a volume in excess of said fluid sample;

(c) fluid sampling means disposed in said elongate body and defining a rigid sample chamber connected to said fluid inlet passage to receive fluid from said pipeline through said fluid inlet passage, said sampling means periodically removing said fluid sample from said fluid inlet passage;

(d) a fluid outlet disposed in said elongate body and connected to said rigid sample chamber of said fluid sampling means for periodic and selective delivery of said fluid sample to a sample storage vessel;

(e) a first check valve disposed in said elongate body and cooperative with said fluid sampling means to prevent fluid flow from said sample storage vessel past said fluid sampling means when pressure in said sample storage vessel exceeds pressure in said pipeline;

(f) a second check valve disposed in said outlet and said elongate body and in fluid communication with said fluid sampling means to permit said selective and periodic delivery of said fluid sample to said sample storage vessel when pressure in said pipeline exceeds pressure in said sample storage vessel, said second check valve being in fluid communication with said pipeline exclusively through passages formed in and through said elongate body; and

(g) a motor in said body for operating said sampling means to direct fluid through said outlet and into the sample storage vessel.15. The assembly of claim 14 wherein said fluid sampling means comprises:

(a) a movable plunger sealingly received in said rigid sample chamber;

(b) means connecting said motor to said plunger to reciprocate said plunger though a first position to allow fluid into said rigid sample chamber, and reciprocate said plunger to a second position to force fluid through said second check valve; and

(c) said motor forming sufficient pressure to open said second check valve and also overcome any back pressure encountered by fluid flow in said outlet.16. The assembly of claim 14 wherein said elongate body is formed by:

(a) a lower end portion having a downwardly extending probe for insertion into a pipeline, and said probe extends from a threaded fitting cooperatively connecting to a mating fitting on the pipeline;

(b) an intermediate portion supporting said outlet and said check valves; and

(c) an upper end portion comprising said second end and supporting said motor means wherein said upper end portion is joined with and connected to said intermediate portion to align said body portions for joinder in an

integrated assembly.17. The assembly of claim 14 wherein said motor comprises a piston in a cylinder defining a fluid receiving compression chamber, and said piston is connected to a plunger movably positioned in said rigid sample chamber to reciprocate, said plunger and rigid sample chamber comprising said fluid sampling means.18. The assembly of claim 14 wherein said fluid sampling means comprises:

(a) a reciprocating plunger;

(b) said rigid sample chamber receiving said plunger to force fluid out of said chamber;

(c) a passage for pressurized fluid from said rigid sample chamber to said outlet.19. The assembly of claim 18 wherein said first check valve comprises:

(a) a valve seat fluidly connected to said outlet;

(b) a valve element cooperative with said valve seat to close said outlet to fluid flow; and

(c) spring means bearing against said valve element to provide a force overcome by fluid pressure on operation of said plunger, said spring means otherwise closing said valve element.20. The assembly of

claim 19 wherein said valve element is a needle valve.21. The assembly of claim 14 wherein said second check valve is a pressure-set check valve in fluid communication with pipeline pressure through said

fluid flow inlet passage.22. The assembly of claim 14 wherein the motor is in fluid communication with the fluid sampling means and pipeline, wherein fluid from the pipeline acting upon the motor means passes through the fluid sampling means.