Modular sample conditioning system

An in-stream sample collection and conditioning system which is easier to implement and maintain, more cost effective, and more reliable than existing systems. The preferred embodiment of the present system contemplates a modular system adaptable to a variety of diverse configurations and criteria, the system having incorporated therein a base piece formed of interconnecting modular base members, the base piece having fluid passageways formed therein to provide fluid flow between the adjacent base member. Situated adjacent to each of the modular base members forming the base piece are modular conditioning components, each selected from a field of diverse conditioning types and configurations, and adapted for the contemplated use. The present invention further contemplates a unique and useful system for joining the various modular components forming the present system, in a manner which provides redundant leak resistance, flexibility in forming various conditioning requirements and adaptability to diverse existing sampling stream interfaces, as well as a new and unique method for attachment of the transport tube to the device body. Lastly, the preferred embodiment of the present invention contemplates a highly precise, low tolerance juxtaposition of the various components forming the present system, utilizing an extremely thin sheet, formed membrane/gasket member, implemented in such a manner as to provide high thermocycling characteristics as well as high pressure tolerance, coupled with a low failure/leakage rate.

TECHNICAL FIELD OF THE INVENTION 
This invention relates to the analysis of fluids in a fluid process stream, 
such as implemented by petrochemical plants, refineries, gas separation 
plants, etc., and in particular to an in-stream sample collection and 
conditioning system which is easier to implement and maintain, more cost 
effective, and more reliable than existing systems. 
The preferred embodiment of the present system contemplates a modular 
system adaptable to a variety of diverse configurations and criteria, the 
system having incorporated therein a base piece formed of interconnecting 
modular base members, the base piece having fluid passageways formed 
therein to provide fluid flow between the adjacent base member(s). 
Situated adjacent to each of the modular base members forming the base 
piece are modular conditioning components, each selected from a field of 
diverse conditioning types and configurations, and adapted for the 
contemplated use, the system dispensing with the necessity of tubes, 
pipes, and traditional fittings. The present system as a whole provides a 
wholly new and unprecedented system for custom building fluid stream 
sampling and conditioning systems with heretofore unavailable 
"off-the-shelf" components. 
The present invention further contemplates a unique and useful system for 
joining the various modular components forming the present system, in a 
manner which provides redundant leak resistance, flexibility in providing 
various conditioning configurations, and adaptability to diverse existing 
sampling stream interfaces. 
Lastly, the preferred embodiment of the present invention contemplates a 
highly precise, low tolerance juxtaposition of the various components 
forming the present system, utilizing an extremely thin sheet formed 
membrane/gasket member, implemented in such a manner as to provide high 
thermocycling characteristics as well as high pressure tolerance, coupled 
with a low failure/leakage rate. 
BACKGROUND AND PRIOR ART OF THE INVENTION 
While the prior art has contemplated various and diverse systems for 
sampling and/or conditioning fluids in a process stream, said prior art 
systems tended to require a "custom" configuration for each site, 
entailing an expensive and time-consuming design, fabrication, and 
installation. 
BACKGROUND 
Overview of Sample Conditioning Systems 
Processes as implemented in, for example, petrochemical plants, refineries, 
gas separation plants, etc. frequently require "on stream" analysis of 
process fluids, which are performed by analyzers located near the fluid 
sample source. Sample fluids flow directly from the source to the analyzer 
through an arrangement of piping and specialty components. This 
arrangement, referred to as a "sample conditioning system", is configured 
to extract fluid sample from the source, transport it to the analyzer; 
and, in the process, condition the fluid so that it is compatible with the 
analyzer. 
Conditioning of the sample fluid by the sample conditioning system may 
consist of, for example: 
(1) filtration to remove unwanted solids or liquids 
(2) coalescing to remove aerosol droplets of liquids 
(3) heating to prevent condensation of vapor 
(4) flow and pressure control and measurement 
(5) cooling to lower the sample dew point or remove unwanted liquid vapor. 
The sample conditioning system may perform additional functions such as 
selection of one of several fluid streams for analysis by a single 
analyzer. This is called "stream selection" or stream multiplexing. 
All of the components utilized for extracting, transporting, and 
conditioning the sample, as described previously, are part of the sample 
conditioning system. Some sample conditioning systems have components 
distributed along the entire distance between the source and the analyzer. 
Typically the largest concentration of these sample conditioning system 
components are located close together. 
Reference to sample conditioning systems in the present invention are 
designed primarily for utilization in conjunction with closely grouped 
component arrangements, although the present system does include 
innovative features which could be useful for more spaced component 
arrangements. The components as implemented in the sample conditioning 
system, which are utilized for conditioning sample fluids, will 
hereinafter be referred to as conditioning components. 
Current Construction of Sample Conditioning System 
Current construction methods for Sample Conditioning System vary little 
from their first appearance several decades ago. Conditioning components 
are typically mounted on a vertical panel or shallow enclosure and are 
interconnected by tubing, piping, and fittings. Heavier conditioning 
components are mounted to the plate or enclosure with brackets while 
lighter conditioning components are supported by interconnecting fittings, 
piping, tubing, etc. Some Sample Conditioning System are further protected 
by "analyzer houses" or shelters which are usually large enough for 
maintenance technicians to work in and may also house process analyzers. 
Common to all of the above configurations is the fact that most Sample 
Conditioning Systems include a uniquely designed and implemented conduit 
system for conveying the fluid from the sample stream, and through the 
components, sometimes resulting in a maze of conduits, thereby resulting 
in high cost, maintenance, and the propensity for leakage from the system. 
Problems Associated With Current Construction Methods 
Several problems arise from the use of current construction methods. Some 
of the major problems are as follows: 
(1) Excessive Size 
Sample Conditioning System produced by current construction methods require 
much space--a commodity which is very valuable in process areas. In 
general, lowering the size of analyzer houses or Sample Conditioning 
System enclosures results in significant cost reduction due to the high 
cost for space in process areas. 
(2) Labor Intensive 
Configuring, mounting and interconnecting of conditioning components during 
the construction of a Sample Conditioning System is very labor intensive 
and therefore costly. 
(3) Excessive Sample Conditioning System Internal Fluid Volume and Static 
Fluid Pocket Volume 
It is well known in the industry that large internal volumes and static 
fluid pocket volume have a negative influence on the performance of Sample 
Conditioning System. The larger the internal volume and/or static fluid 
pocket volume in a Sample Conditioning System and the longer it takes to 
sweep it our after a sample fluid composition change occurs. Therefore 
Sample Conditioning System with large internal and/static fluid pocket 
volume require larger amounts of fluid to sweep, resulting in significant 
inefficiency. 
In most cases it is desirable for fluid sample composition arriving at an 
analyzer to track closely the composition of the sample fluid at its 
source. In many instances the sample fluid utilized for sweeping cannot be 
returned to the source and therefore must be wasted. Therefore reducing 
the internal and static fluid cost related to loss of sample fluid and its 
environmentally safe disposition. Tube and pipe interconnections between 
conditioning components contribute the bulk of a Sample Conditioning 
System's internal volume. Fittings, especially pipe fittings, introduce 
static fluid pocket volume to the Sample Conditioning System. 
(4) Safety and Environmental Concerns 
It is common for sample fluid leaks to occur in conditioning component 
tubing and pipe interconnections and as a result of conditioning component 
failures. Examples of common conditioning component failures are: pressure 
regulator diaphragm ruptures and valve stem packing shrinkage due to wear 
or temperature changes. When fluid leaks occur, maintenance technicians 
can be exposed to toxic materials and fire or explosion hazard. Fluid used 
for continuously sweeping a Sample Conditioning System presents disposal 
problems and increases operational expenses. 
PRIOR ART 
While the prior art may have contemplated in some degree the utilization of 
block components having fluid passageways therethrough for fluid 
conditioning and/or conveyance, said prior art known to the inventor has 
been limited to hydraulics and other distinguishable configurations and 
applications. 
For example, U.S. Pat. No. 3,831,953, issued 1974 to Leibfritz et al 
contemplates a "Solenoid Operated Valve Assembly", teaching a "sealing 
unit adapted to be clamped between parallel faces of mating valve parts, 
comprising a sheet-like resilient gasket member engaged with one of said 
faces, and a uniform thickness plate member engaged with the other of said 
faces, said gasket member having apertures bounded one side only by 
lateral rib means which extend beyond the thickness thereof so that said 
gasket member is squeezed at the rib means between said parallel faces. 
While the '953 device may contemplate a redundant leak isolating system 
(see col 5, lines 528, for example), the system fails to contemplate the 
overall method and apparatus of the present invention, as pertaining to 
modular sampling components. The system is clearly designed as valve 
assembly in a hydraulic system, and as such would not be able to be 
utilized in the present invention. Other differences between '953 and the 
present invention will be made clear in the discussion following infra. 
GENERAL SUMMARY DISCUSSION OF THE INVENTION 
Unlike the prior art, the present invention provides a cost effective, 
relatively easily implemented, reliable, and efficient system for 
in-stream sampling, adaptable to a variety of configurations and 
conditions. 
The invention includes a method for: 
(a) Constructing a sample fluid conditioning system utilizing modular base 
and modular conditioning components. This method eliminates tube and pipe 
interconnections and fittings. This reduces static fluid pocket volume and 
internal system volume, reduces mounting space requirements, and decreases 
the time and skill required to construct a sample conditioning system. It 
also decreases the time required for replacement of failed conditioning 
components. 
(b) Constructing base and conditioning modules. The method further reduces 
internal and static fluid pocket volume of sample conditioning systems 
fabricated from modules constructed by this method. This method also 
provides a means for capturing and transporting to an external disposal 
system any sample fluids which would otherwise leak to the sample 
conditioning modules external environment as a result of fluid breaching a 
fluid barrier or failure of a conditioning component. 
(c) Constructing fluid barriers between two surfaces. This method provides 
a means for leak-free communication of fluids between passageways of 
adjoining base and conditioning modules and also between passageways of 
adjoining base modules. This method of constructing fluid barriers also 
accommodates the capturing of leaks across a primary fluid barrier to 
prevent fugitive emission of sample fluid. The fluid barriers constructed 
by this method remain leak free even after thermo-cycling. 
(d) Compressing fluid barrier material between two surfaces utilizing 
strain in a threaded member for supplying the required compressive force. 
This method compensates for displacement in the seal barrier material 
which would otherwise reduce the compressive force and permit fluid leaks. 
(e) Retaining fluid barrier material utilizing beveled surfaces. This 
method permits the use of thin plastic or elastic fluid barrier materials 
and is less susceptible to displacement when thermo1 cycled. 
(f) Mounting modular base and modular conditioning components in a manner 
which provides the clamping force required for sealing of fluids. 
(g) Attaching fluid transport tube to a base module in a manner that 
prevents sample fluid leaks to the surrounding environment in the event of 
a primary fluid barrier failure. 
It is therefore an object of the present invention to provide a modular 
system for in-stream sampling of a fluid in a fluid sampling stream. 
It is another object of the present invention to provide an in-stream 
sampling system which may be utilized in conjunction with a variety of 
system configurations and requirements, without the need for custom fluid 
conveyance means, such as piping, conduits or the like. 
It is still another object of the present invention to provide a system for 
in-stream sampling, comprising a modular base member adapted to have 
situated thereupon, in fluid impermeable fashion, a diverse assortment of 
communicating fluid conditioning modules. 
It is still another object of the present invention to provide a redundant 
leak sealing means to prevent fugitive emissions. 
It is still another object of the present invention to provide an 
ultra-thin gasket sealing system configured to provide high thermocycling 
tolerances, and perform satisfactorily in a broad range of temperature 
extremes. 
Lastly, it is an object of the present invention to provide an ultra-thin 
gasket sealing system configured to provide an effective, low maintenance, 
high-pressure seal.

DETAILED DESCRIPTION OF THE INVENTION 
The preferred embodiment of the present invention includes a novel method 
for constructing sample conditioning systems. Said method simplifies 
construction, reduces construction time, improves performance, is safer to 
operate and maintain and essentially eliminates fugitive sample fluid 
emissions to the environment. In this method, conditioning components such 
as valves, pressure regulators, flowmeters and filters are constructed in 
a modular fashion. 
The conditioning component modules are mounted to a modular base, as shown 
in the block having conduits formed therein in FIG. 1. In FIG. 1, the 
conditioning component module 11, shown, is designed to perform a valve 
function, and is shown mounted to base module 12. The present invention 
provides for essentially all types of conditioning components to be made 
modular and mounted to base modules such as (12), above, and is not 
limited to the conditioning component having a valving function as 
illustrated in FIG. 1. 
Base modules with mounted conditioning modules are then arranged in a side 
by side fashion as shown in side view FIG. 2. In FIG. 2, base modules 57, 
58, 59, 60, 61, 62, and 63 can be seen in a side by side arrangement with 
mounted conditioning components 64, 65, 66, 67, 68, 69 and 70. A means, 
not shown in FIG. 2, retains the modules in their side by side orientation 
and provides for mounting of the entire module assembly. Internal passages 
in conditioning component modules and base modules conduct sample fluid 
through the network of conditioning components in accordance to 
predetermined fluid flow requirements. Novel-fluid barrier means between 
base modules and between base modules and component modules prevent 
undesired fluid flow between internal passages and also prevent fluid 
leaks to the environment. 
Fluid passes directly from a passage in one module to a passage in another 
module without the need for interconnecting pipes, tubing or fittings, via 
the base member, which conveys the fluid via conduits formed therein to 
adjacent conditioning modules, which mount upon the base at aligned, 
predesignated conduit coordinates. Because there is no need for excessive 
piping, the present system provides an efficiency which aids in 
simplifying the construction task, reduces overall cost, and significantly 
improves function by eliminating static fluid pocket volume and reduces 
sample conditioning systems internal volume. 
Prior art methods of construction relate primarily to pneumatic and 
hydraulic fluid control modules, such as shown in U.S. Pat. No. 3,831,953, 
discussed infra while the preferred embodiment of the present invention 
addresses problems associated with sample fluid conditioning for analysis 
by automated analyzers. The needs are very different. For example, of 
prime importance in sample fluid conditioning is the need for minimal 
internal system volume, and the absence of static fluid pocket volume. 
This is not a requirement in typical pneumatic or hydraulic fluid control 
devices. Another example is the need in sample fluid conditioning systems 
for minimizing or eliminating fugitive fluid emissions resulting from 
fluid leaks which also is not a usual requirement for pneumatic or 
hydraulic fluid control devices. 
The method of utilizing conditioning component modules and base modules in 
the particular manner hereafter described allows conditioning component 
modules to be designed and constructed without compromise with regard to 
the need for fluid communication between and among other conditioning 
component modules. With this method, internal fluid passages in 
conditioning components modules need only mate at any point along 
appropriate horizontal passages in the base modules. These horizontal 
fluid passages in all of the base modules may be standardized with regard 
to location of the openings which communicate sample fluid to adjacent 
base modules. The task of designing passages in conditioning component 
modules to mate with horizontal passages in the base module is 
substantially easier than designing conditioning component modules which 
intercommunicate, without use of base modules, with adjacent conditioning 
component modules. 
Schematic Flow Diagram 
Prior to constructing a sample conditioning system utilizing component 
conditioning modules and base modules, one must first establish a 
schematic flow diagram. An example of such a diagram, as seen in FIG. 3, 
must include the conditioning components, such as valves 1, 2, and 3; 
filter 4, flow meters 5, and 6; and pressure regulator 7, which will be 
required to provide the desired sample fluid conditioning for a specific, 
exemplary application. The fluid communication circuits between 
conditioning components should also be indicated by the schematic flow 
diagram. In the schematic flow diagram of FIG. 3 there are three fluid 
circuits. The first fluid circuit is comprised of passage 8 valve 1 and 
passage 39. The second fluid circuit is comprised of a portion of filter 4 
which includes filter element 45, passage 10, pressure regulator 7, 
passage 40, valve 2, passage 41, flowmeter 5, and passage 42. The third 
fluid circuit consist of a portion of filter 4, passage 9, valve 3, 
passage 43, flowmeter 6 and passage 44. 
It should be noted that the schematic flow diagram of FIG. 3 is an example 
of a typical sample conditioning system. However, the invention applies to 
all types of sample conditioning system some of which maybe substantially 
more complex and include conditioning components not shown in FIG. 3. 
In normal operation of the sample conditioning system of FIG. 3, sample 
fluid enters at entrance 46 of passage 8 then flows through the first 
fluid circuit. The first fluid circuit flow then branches into the second 
and third fluid circuits upon entering filter 4. Fluid exits the second 
fluid circuit from passage 42 into an analyzer not shown. Fluid exits the 
third fluid circuit from passage 44 to a safe disposal system not shown. 
The fluid flow rate through the first fluid circuit is equal to the sum of 
the fluid flow rates of the second and third fluid circuits. The purpose 
of the second fluid circuit is to condition sample fluid so that it is 
compatible with a given analyzer. In this particular case the fluid is 
filtered by filter element 45, fluid pressure is controlled by pressure 
regulator 7, fluid flow rate is controlled by valve 2, and flow rate is 
monitored by flowmeter 5. Passages 10,40,41, and 42 provide fluid 
interconnections between conditioning components. 
The amount of time required for sample fluid to be transported from a 
source to an analyzer is commonly referred to as the system lag time. The 
system lag time represents the minimum time required for an analyzer to 
respond to a composition change at the sample fluid source. Fluid flow 
rate through the sample conditioning system has a direct impact on system 
lag time. 
The purpose of the third fluid circuit is to aid in adjusting the total 
fluid flow rate in the first fluid circuit. Altering the flow rate of the 
third fluid circuit using valve 3 changes the fluid flow rate of the first 
fluid circuit and subsequently impacts the system lag time. The fluid 
circuit arrangements and conditioning components which can be included in 
a sample conditioning system are not limited to those referenced in FIG. 
3. The schematic flow diagram established need not be tangible. A mental, 
computer generated, or any other means for establishing a schematic flow 
diagram containing the aforementioned information will suffice. The 
purpose for the schematic flow diagram is to aid in the selection of 
component conditioning modules and base modules which will be utilized in 
the construction of a modular sample conditioning system. 
Mounting a Conditioning Component Module to a Base Module and the Resulting 
Typical Fluid Flow Paths 
After a schematic flow diagram has been established the required component 
conditioning modules, which have been designed to perform specific sample 
fluid conditioning functions, are mounted to their respective base 
modules. An example of this is seen in FIG. 4 where a component 
conditioning module 11, designed to perform a fluid metering valve 
function, is mounted to base module 12. Base modules are specifically 
designed to provide the fluid communication with the component 
conditioning module to which it is mated and other conditioning component 
modules and base modules. Base modules also provide fluid communication 
between other base modules and component conditioning modules. In the 
example shown in FIG. 4 it can be seen that sample fluid 122 entering base 
module 12 at passage opening 20, flows through passage 13, passage 14, 
passage opening 21, opening 28 in fluid barrier material 30, enter 
component conditioning module 11, at passage opening 22, flow through 
vertical passage 15, horizontal passage 16, valve cavity 31, vertical 
passage 17, exit the component conditioning module 11 at the passage 
opening 23, flow through opening 29 in seal barrier material 30, re-enter 
base module 12 at passage opening 24, flow through vertical passage 18, 
horizontal passage 19, exit base module 12 at passage opening 33 and enter 
adjacent base module 12A. 
The metering valve 25 comprised of valve stem 27, stem tip 32, and valve 
seat 26 operates in a conventional manner, thus by rotating valve stem 27 
the action of male thread 38A and female thread 38B causes the stem tip 32 
to change its position relative to valve seat 26 which in turn alters the 
resistance to fluid flowing through valve cavity 31. FIG. 4 illustrates 
how sample fluid flows through a typical component conditioning module and 
base module combination. 
From this example it can be clearly seen that it is possible to mount many 
different types of component conditioning modules to base modules, and 
that in a similar manner sample fluid can be transported from a first 
passageway opening in the base module, through internal passages of the 
base module, into a component conditioning module for the purpose of 
performing a specific sample fluid conditioning function, re-enter the 
base module exit through a second passage opening in the base module and 
thereon flow into an adjacent base module. 
Containment of Fluid Leaks Across a Primary Fluid Barrier 
Many conditioning components designed by prior art methods are susceptible 
to leakage of fluids to the environment which is generally referred to as 
fugitive emissions. Typical sources of fluid leaks in conditioning 
components are damaged static fluid barriers, dynamic fluid barriers, and 
fluid containment barriers such as diaphragms in pressure regulators. 
Other common sources of fluid leaks to the environment in prior art are 
threaded pipe and tube interconnecting fittings. The invention prevents 
fluid leaks of all sources from entering the environment. It accomplishes 
this by capturing the leaking fluid and transporting it to an external 
site. FIG. 5 illustrates how, in the case of a dynamic fluid barrier 
failure, leaking fluid 187 is captured and transported to the base module 
12's fluid containment passage 47. 
Under normal operation lower stem fluid barrier 56 prevents sample fluid 
122 from entering the fluid containment network of base module 12 and 
component conditioning module 11 which is comprised of cavity 54, passages 
53, 52,48, and 47. Upper stem fluid barrier 55 is a barrier between the 
external environment and cavity 54. 
In the event of a lower stem fluid barrier 56 failure, sample fluid 122 
enters cavity 54, flows through horizontal passage 53, vertical passage 52 
and vertical passage 48 into horizontal passage 47 where it is 
subsequently transported, by way of the sample conditioning system's fluid 
containment network to an external disposal site. Upper stem fluid barrier 
55 prevents sample fluid 122 in cavity 54 from leaking to the external 
environment. The Sample Conditioning System's fluid containment network is 
comprised of horizontal passages 47 and corresponding passages in other 
base modules of the Sample Conditioning System. When base module with 
mounted conditioning component modules are assembled side by side as shown 
in FIG. 6, the vent collection passage of each base module mechanically 
align and are in fluid communication. 
Together fluid containment passages 47, 70, 71, 72, 73, 74, and 75 of 
assembled base modules comprise the Sample Conditioning System's fluid 
containment network 76. When Sample Conditioning System's fluid 
containment network 76 is in fluid communication with an external disposal 
site not shown, sample fluid 187 captured in any of the conditioning 
component module and base modules fluid containment networks will be 
transported and vented to the external disposal site. 
The fluid containment network of a conditioning component module and base 
module mating combination may collect sample fluid leaks from a plurality 
of sources. In all such cases however, the captured leaking fluid will be 
transported to the conditioning component module and base module's fluid 
containment passage where it will ultimately be vented to the external 
disposal site by way of the Sample Conditioning System fluid containment 
network 76. 
It should be noted that the Sample Conditioning System's fluid containment 
network 76 is normally maintained at a pressure lower than the sample 
fluid pressure in conditioning component module and base module. Typically 
the fluid containment network 76 pressure is within 5 PSI of atmospheric 
pressure. The differential pressure across upper stem fluid barrier 55 
being typically less than 5 PSI reduces the risk of sample fluid breaching 
this fluid barrier. 
In order for sample fluid to leak to the atmosphere, lower stem fluid 
barrier 56 and upper stem fluid barrier 55 would have to fail 
simultaneously. If in some cases sample fluid leaking to the atmosphere 
presents an excessive hazard, then the Sample Conditioning System fluid 
containment network 76 should be maintained at sub atmospheric pressure. 
This will insure that if upper stem fluid barrier 55 is damaged sample 
fluid will not flow to the atmosphere, instead, gas from the surrounding 
environment will flow into the Sample Conditioning System fluid 
containment network. In a similar manner other types of dynamic fluid 
barriers and static fluid barriers can be prevented from leaking sample 
fluids to the environment when a fluid barrier failure occurs. 
The junction where two passage openings, located on separate conditioning 
components module's or base modules, are in fluid communication are called 
passage junctions. A typical passage junction 95 is seen in FIG. 5. 
Passage opening 49, fluid barrier opening 50, and passage opening 51 in 
combination comprise passage junction 95. Passage junctions must be sealed 
to prevent sample fluid from leaking to the external environment or into 
other passage junctions. 
It can be seen in FIG. 7 that without special provisions fluid 122 
contained in passages of may be and base modules 12 and 12A can leak from 
a passage junction into the environment; such as is seen at 77a, 77b, and 
77c; or into other passage junctions as seen at 78a, and 78b. From FIG. 7 
it can also be seen that fluid leaks could occur on both sides of fluid 
barrier material 30 if precautions were not otherwise taken. 
Therefore the method of sealing to prevent fluid leaks from occurring at 
passage junctions must protect against fluid leaks which could arise on 
either or both sides of seal barrier material 30. The invention includes a 
special method for sealing around passage junctions which are between 
conditioning component module and base module and also passage junction 
which are between two adjacent base module's. The passage junction sealing 
method of the invention provides two series fluid barriers separated by a 
collection passage on both sides of fluid barrier material 30. 
The following method describes the preferred embodiment for construction of 
a static fluid barrier between a conditioning component module and a base 
module such method providing, on both sides of the fluid barrier material, 
two series seal separated by a collection passage in fluid communication 
with an external disposal site. 
Referring to FIGS. 8, 9, and 10, the method consists of the following: 
A first passage groove 81 (FIG. 8) is formed in the surface 91 of base 
module 12 surrounding passage openings 21 and 24 and intersecting passage 
opening 49. 
A second passage groove 82 is formed which intersects opposite sides of 
passage groove 81, and passes between passage openings 21 and 24. Passage 
grooves 81 and 82 are formed in a manner that will provide a space 86 
surrounding passage opening 24; a space 85 surrounding passage opening 21; 
and a space 87 surrounding passage groove 81. 
A third passage groove 83 is formed in the under surface 92 of conditioning 
component module 11 surrounding passage openings 22 and 23 and 
intersecting passage opening 51. 
A forth passage groove 84 is formed which intersects opposite sides of 
passage groove 83 and passes between passage openings 22 and 23, passage 
grooves 83 and 84 are formed in a manner that will provide a space 90 
surrounding passage openings 23, a space 89 surrounding passage openings 
22; and a space 88 surrounding passage groove 83. 
Conditioning component module 11 is then mounted to base module 12 (FIG. 9 
and 10). When mounted as shown in FIG. 9, passage grooves 83 and 84 in 
conditioning component module 11 are in approximate alignment and have the 
same approximate shape and geometry as passage 81 and 82 of base module 
12, In the preferred embodiment a fluid barrier material 30 is inserted 
between conditioning component module 11 and base module 12, Bolts 34 and 
35 secure the alignment between conditioning component 11 and base module 
12. Other fastening means may be used for this purpose. Openings 28 (FIGS. 
4, 5, 8, and 9) in the fluid barrier allows fluid to flow between passages 
14 and 15; opening 29 allows fluid to flow between passages 17 and 18; and 
opening 50 (FIG. 5) allows fluid to flow between passages 48 and 52. 
By tightening bolts 34 and 35 (FIG. 10) conditioning component module 11 
and base module 12 apply a force to opposite sides of fluid barrier 
material 30. The first fluid barrier 96 (FIGS. 4, 4A, 4B, 4C, 5, and 8) 
around the passage opening junction 93; comprised of passage openings 21, 
fluid barrier opening 28 and passage opening 22; is formed by space 85 on 
base module 12, space 89 on conditioning component module 11 and the 
segment 103 of fluid barrier 30 which is sandwiched directly between space 
85 and 89. The first fluid barrier 96 is surrounded by segments of groove 
81 and groove 82 on base module 12 and grooves 83 and 84 on conditioning 
component module 11. 
The second fluid barrier 97 around passage opening junction 93 is formed by 
space 86, 87, 88, and 90 and the segment of fluid barrier 104 material 
sandwiched directly between spaces 86 and 90; and segment of fluid barrier 
material 105 between space 87 and 88. Passage grooves 81, 82, 83, and 84, 
in combination, surround passage opening junction 93 on both sides of 
fluid barrier 30, in a manner that divides the first fluid barrier 96 and 
second fluid barrier 97 of passage opening junction 93. In the event that 
sample fluid breaches the first fluid barrier 96 encircling passage 
opening junction 93, on either or both sides of fluid barrier 30, passage 
grooves 81, 82, 83, and 84 will capture the fluid and transport it to 
passage junction 95; comprised of passage opening 49, passage opening 51, 
and fluid barrier opening 50; into passage 48 then into horizontal passage 
47 where it will be subsequently vented to an external disposal site as 
previously described. The second fluid barrier 97 in the event of a leak 
contains fluid within the passage grooves 81, 82, 83, and 84 preventing it 
from leaking to the surrounding environment or into adjacent passage 
junction 94. 
The first fluid barrier 98 around passage junction 94; comprised of passage 
opening 24, fluid barrier opening 29, and passage opening 23, is formed by 
space 86 on base module 12, space 90 on conditioning component module 11, 
and the segment 104 of fluid barrier 30 which is sandwiched directly 
between space 86 and 90. 
The second fluid barrier 99 around passage junction 94 is formed by space 
85, 87, 88, and 89 and the segment of fluid barrier 105 sandwiched between 
space 88 and 87; and segment of fluid barrier 103 sandwiched between space 
85 and 89. Passage grooves 81, 82, 83, and 84 in combination surround 
passage opening junction 94, on both sides of fluid barrier 30 in a manner 
that divides the first fluid barrier 98 and second fluid barrier 99 of 
passage opening junction 94. 
In the event that sample fluid breaches the first fluid barrier 98 
encircling passage opening junction 94, on either or both sides of fluid 
barrier 30, passage grooves 81, 82, 83, and 84 will capture the fluid and 
transport it to passage junction 95, into passage 48, then into horizontal 
passage 47 where it will be subsequently vented to an external disposal 
site as previously described. 
As an alternate means, collection passage grooves may be formed in the 
fluid barrier material in special cases. However, in the preferred 
embodiment collection passage groves are formed on the surface of the 
conditioning component module and base module as previously described. 
Fluid barrier 100 prevents fluid communication between the external 
environment and passage junction 95; and between the external environment 
and groove 81 and 83. Passage junction 95 is comprised of passage opening 
49, fluid barrier opening 50, and passage opening 51. Fluid barrier 100, 
is formed by space 87 on base module 12, space 88 on conditioning 
component module 11, and the segment 105 of fluid barrier material 30 
which is sandwiched between space 87 and space 88. Seal barrier segment 
105, when conditioning component module 11 is mounted to base module 12 
and fluid barrier material 30 is inserted between, surrounds passage 
groove 83 of the conditioning component module 11, passage groove 81 of 
base module 12, and vent passage junction 95. 
Effects of Fluid Barrier Thickness and Clamping Force on Prevention of 
Fluid Barrier Breach 
It can be seen in FIG. 10 that by turning screws 34 and 35 in a direction 
which will increase thread engagement, that an increasing amount of force 
can be applied to the opposite sides of fluid barrier material 30 by 
conditioning component module 11 and base module 12. In the preferred 
embodiment the combined force applied by screws 34 and 35 is sufficient to 
overcome the opposing force resulting from the internal fluid pressure in 
conditioning component module 11 and base module 12 plus apply 
approximately 2000 pounds per square inch additional clamping pressure to 
their surface which is in contact with the opposite sides of fluid barrier 
material segments 103, 104, and 105. The absolute amount of clamping force 
applied to fluid barrier material segments 103, 104, and 105 to effect 
containment of sample fluids as previously described will depend upon the 
type of fluid barrier material 30 utilized and its thickness, and the 
range that the temperature of the fluid barrier 30 is cycled during the 
course of its service life. 
It is highly desirable in a sample conditioning system that its material of 
construction are inert. Therefore and ideal fluid barrier material 30 is a 
sheet of TEFLON.TM. plastic. It is well known in the prior art that fluid 
barriers constructed from TEFLON.TM. plastic are susceptible to leakage 
due to plastic displacement, especially when its temperature is cycled 
through a wide range at elevated temperatures. 
This is overcome in the present invention by several means. First, in the 
preferred embodiment, fluid barrier material thickness is minimized and 
preferably less than 0.040 inches and more preferably less than 0.010 
inches. By minimizing the thickness of fluid barrier material 30, 
compensation for its plastic displacement can be more easily effected. 
Although many means exist to compensate for fluid barrier material 30 
plastic displacement, the preferred means are by pre-loading bolts 34 and 
35 to produce a strain of a value equal to or exceeding the maximum 
potential reduction of thickness of fluid barrier material 30 resulting 
from plastic displacement. 
It has been well established by prior art that bolts may be safely torqued 
to produce a stress equal to approximately 60% of the bolts tensile 
strength. In the preferred embodiment 304 stainless steel is utilized, 
however, many other types of material may be used for this purpose. The 
tensile strength of 304 stainless steel is approximately 92,000 pounds per 
square inch. At 60% of this value, which is 55,200 pounds per square inch, 
the strain is approximately 0.0018 inches per inch of free bolt length. 
The free bolt length is defined as the portion of bolt 34 and 35 which is 
not engaged in female thread. Minimizing the thickness of fluid barrier 
material 30, minimizes the plastic deformation compensation requirement 
for fluid barrier material 30. 
The minimum thickness at which fluid barrier material 30 can still 
effectively function as a fluid barrier is dependent upon the surface 
roughness of surface 92 of conditioning component module 11 and surface 91 
of base module 12. 
Through experimentation it was found that a fluid barrier material 
thickness of 0.005 inches was effective in sealing machined surfaces with 
roughness of 64 micro inches. It was also empirically determined that when 
Teflon.TM. is the fluid barrier material 30 an initial net clamping force 
of 2000 pounds per square inch applied across opposite sides of fluid 
barrier surface is required to contain or seal without leakage fluids 
which are under a pressure of 1000 pounds per square inch. The net 
clamping force is defined as the clamping force applied to the fluid 
barrier material exclusive of the opposing force resulting from internal 
fluid pressure. 
It was also determined that when Teflon.TM. is the fluid barrier material 
30, a net clamping force of 500 pounds per square inch applied across 
opposite sides of fluid barrier surface is required to contain or, seal 
without leakage, fluids which are at a pressure no greater than 50 pounds 
per square inch. From this it was concluded that a minimum of 500 pounds 
per square inch clamping force was required to effect sufficient plastic 
displacement of the Teflon.TM. fluid barrier material 30 to fill and seal 
surface irregularities of surfaces 91 and surface 92. Clamping forces were 
for the most part applied and measured by means of torque gauge at ambient 
temperatures ranging from 70.degree. F.-75.degree. F. 
When constructing a fluid barrier according to the invention observe the 
following steps for selecting and forming fluid barrier material 30 and 
also to select and tighten the bolts which apply the net clamping force to 
both sides of fluid barrier material 30. 
(a) Select a sheet of fluid barrier material 30. Preferably the thickness 
is approximately 0.005 inches. 
(b) Shape the exterior of the selected sheet of fluid barrier material 30 
to conform approximately with the exterior shape of base module 12 and 
conditioning component module 11. 
(c) Form openings through the sheet of fluid barrier material 30 which will 
provide fluid communication between corresponding passages of base module 
12 and conditioning component 11. 
(d) Select the number and diameter of bolts which will supply the required 
clamping force between opposite side of the fluid barrier material 30, 
when torqued to approximately 60% of the bolts tensile strength. ( 
e) Select bolt lengths which will, when torqued to 60% of tensile strength, 
result in a strain equal to or greater than the thickness of the fluid 
barrier material 30. 
Reducing the effective fluid barrier area reduces the number and/or size of 
bolts required to produce the desired clamping force. This can be easily 
done by reducing the area of the surface 91 and 92 which contact and apply 
clamping force to segments of fluid barrier material 30. Forming a 
depression of 0.010 inches to 0.015 inches in the surface of 91 and 92 
where contact with the fluid barrier material 30 is not desired can be 
used as a means for reducing the effective fluid barrier contact area 
which in turn reduces the clamping force required. 
As an example in FIG. 11 a surface depression 120 is formed in space 87 of 
surface 91 and a surface depression 121 is formed in space 88 of surface 
92. Depression 120 reduces the area of space 87 which contacts segment 105 
of fluid barrier material 30 and depression 121 reduces the area of space 
88 which contacts segment 105 of fluid barrier material 30. 
If the bolt length 34 and 35 required to traverse conditioning component 
module 11 is not sufficiently long to produce a strain equal to or greater 
than the thickness of fluid barrier material 30 than the bolt length can 
be increased by use of spacers 101A and 101B as shown in FIG. 12. 
It has been determined that, as plastic displacement of fluid barrier 
material occurs thereby reducing bolt strain, the net clamping force 
required on opposite sides of fluid barrier material 30 to effect fluid 
sealing is diminished accordingly. This is probably due to filling of 
irregularities of surface 91 and 92 by fluid barrier material as 
previously mentioned. 
It was found that when the fluid barrier material 30 thickness was 0.005 
inches and the bolt 34 and 35 lengths were at least two inches long the 
first fluid barrier around the passage junctions were not breached by 
fluids at pressures in excess of 1000 pounds per square inch after 
extensive thermocycling from approximately 32.degree. F. to 450.degree. F. 
Effect of Surface Geometry on Prevention of Fluid Barrier Breaching 
Tests indicate that some of the major factors relating to fluid barrier 
blowout at high fluid pressures are the edge area of fluid barrier exposed 
to the fluid pressure, the plastic properties of the fluid barrier 
material 30, and the friction between he fluid barrier material 30 and the 
surfaces 91 and 92. With a given plastic material of construction of the 
fluid barrier material fluid pressure which causes fluid barrier blowout 
can be significantly increased by reducing the fluid barrier thickness in 
order to minimize its area exposed to fluid pressure. 
Testing also revealed that for a given fluid barrier material the maximum 
leak-free operating pressure of internal fluids could be significantly 
extended by forming a slope on one or both sides in contact with he 
opposite sides of fluid barrier material. In FIG. 13 it can be seen that 
surface segment 106 of conditioning component module 11 and surface 
segment 107 of base module 12 are sloped. When a sufficient net clamping 
force (FIG. 14) is applied between conditioning component module 11 and 
base module 12 sloped surface 106 and 107 displace a portion of fluid 
barrier material 30, thereby creating a wedge shaped fluid barrier 108 
sloped in opposition to the direction of the potential internal pressure 
applied by sample fluid 122 in passage grooves 81 and 83 and passage 
junctions 93 and 94 as shown in FIG. 14. The effect of increasing internal 
fluid pressure of sample fluid 122 is the wedging of fluid barrier 108 
thereby creating a tighter seal. Fluid 122 may be present in passage 
grooves 81 and 83 in the event of a massive passage junction fluid barrier 
failure. The forming of a wedge shaped second fluid barrier is an 
additional measure of protection against sample fluid leaking to the 
environment. 
In FIG. 15, it can be seen that a single sloped surface 106 of conditioning 
component module 11 is used in conjunction with flat surface 87 of base 
module 12. 
After sufficient clamping force has been applied between conditioning 
component module 11 and base module 12 to cause fluid barrier 30 to 
undergo plastic displacement, it can be seen that a 1/2 wedge shaped fluid 
barrier 113 was formed. The effect of increasing internal fluid pressure 
of sample fluid 122 in passage grooves 81 and 83 and passage junctions 93 
and 94 is wedging of fluid barrier 113 thereby creating a tighter seal. 
In the preferred embodiment the depth of the sloped surfaces 106 and 107 is 
approximately 50% of the fluid barrier material 30 thickness and the fluid 
barrier material 30 thickness is less than 0.010 inches. In any case 
however, it is preferred that the depth of sloped surfaces 106 and 107, 
the depth of surfaces depressions 110 and 111, and he thickness of fluid 
barrier material 30 in combination, after sufficient clamping force has 
been applied between conditioning component module 11 and base module 12 
to effect plastic displacement of fluid barrier 30, permit sloped surfaces 
106 and 107 to make physical contact (FIG. 16). Depending on many factors 
such as the type and thickness of fluid barrier material 30, the initial 
clamping force between conditioning component module 11 and base module 12 
may not result in plastic displacement until some period of time has 
elapsed. 
The passage junctions between adjacent base module's in a Sample 
Conditioning System can be prevented from leaking fluid to the environment 
and to other passage junctions in a manner similar to that previously 
described by forming two fluid barriers and a leak containment passage 
around the passage junctions which are between a conditioning component 
module and base module. An example of this can be seen in FIG. 17 where 
passages 192A, 193A, 194A, and 195A of base module 187 form junctions with 
corresponding passages 192B, 193B, 194B, and 195B of base module 188 and 
opening 192C, 193C, 194C, and 195C of fluid barrier material 189. 
Collection grooves 190, 191, and 192 and passages 195A and 195B in 
concert, provide two series fluid barriers separated by a fluid collection 
passage in conformance with the invention and as previously detailed for 
conditioning component module 11 and base module 12. Therefore, 
hereinafter, when base modules are assembled side by side it must be 
assumed that the resulting passage junctions are rendered leak-free by the 
aforementioned methods. 
Function and Attributes of Passages 
In a manner similar to that in which corresponding vent collection passages 
47, 70,71, 72, 73, 74 and 75 of a plurality of base modules shown in FIG. 
6 form a continuous passage 76 comprising a Sample Conditioning System 
fluid containment network as aforementioned, other continuous Sample 
Conditioning System passages can be formed for various purposes. As an 
example in FIG. 6 passages 114A, 114B, 115A, 115B, 116A, 116B, 117A, 117B, 
118A, 118B, 119, and 123 comprise a passageway 124 in which sample fluid 
may flow through the desired component modules whereon sample conditioning 
occurs. Sample fluid in this example is conditioned in the manner required 
by the aforementioned first and second fluid circuits of the diagram of 
FIG. 3. A second example in FIG. 6 are passageways 125, 126, 127, 128, 
129, 130A, 130B, and 131A, and 131B comprising passageway 132. In this 
example passages 130A, 130B, 131A, and 131B provide fluid communication 
among the component modules required by the aforementioned third fluid 
circuit of the diagram of FIG. 3. Passages 125, 126, 127, 128 and 129 
serve as a conduit for sample fluid flow to an external destination not 
shown. 
A third example is shown in FIG. 6 where corresponding passages of the 
assembled base module comprise a forth Sample Conditioning System passage 
133 which in a preferred embodiment may function as a fluid transport 
passage for auxiliary fluids. Examples of auxiliary fluids which are 
anticipated for use in the Sample Conditioning System constructed by the 
methods of the invention are inert fluid for purging or cleaning the 
interior of the Sample Conditioning System and pressurized fluid for 
actuation of mechanical components such as automated valves. 
Although not shown in FIG. 6, the passage junctions between adjacent base 
modules are sealed by the same method as previously described to seal 
passage junctions between conditioning component module 11 and base module 
12, and between base modules 187 and 188, including the two fluid barriers 
with passage grooves formed in exterior surfaces for the purpose of 
collecting fluids which may breach the first fluid barrier of a passage 
junction. 
Sample Conditioning System passages such as passages 76, 124, 132, and 133 
seen in FIG. 6 formed and sealed in accordance with the methods of the 
invention are substantially better suited for transport of sample fluid 
within a Sample Conditioning System then the fluid transport passages of 
prior art. It can be seen in FIG. 18 that prior art use of pipe fittings 
in forming transport passages results in dead volume and tends to add to 
the overall Sample Conditioning System internal fluid volume. It can be 
seen that a segment of male threads 134, with the aid of fluid barrier 
material 136, form a fluid seal in combination with a segment of female 
threads 135. The cavity 143 between male thread segment 137 and female 
thread segment 138 is not in the direct path of sample fluid 139 flowing 
between passages 141 and 142. The cavity 140, formed between the leading 
surface 145 of male pipe fitting 146 and the bottom surface 144 of female 
pipe fittings 147, forms a reservoir for sample fluid 139. 
The trapping or removing of sample fluids by cavities 140 and 143 from the 
direct sample fluid flow paths of passages 141 and 142 is highly 
undesirable. The effect of these type cavities on analytical results is 
well known in the art. The inventions method of forming, joining and 
sealing of sample fluid passages provide minimum volume passages absent 
static fluid pocket volume. An example of this is seen in FIG. 4 where 
passages 14 and 15 are joined at passage junction 93, the passage junction 
93 performs a function similar to that of the aforementioned male pipe 
fittings 146 and female pipe fittings 147. Yet the interior of passage 
junction 93 does not contain dead or unpurged cavities such as cavity 143, 
nor does it have and enlarged volume such as cavity 140. Passage junction 
93 provides near ideal characteristics for transporting sample fluids in a 
Sample Conditioning System. 
Assembly and Mounting of Modules to Construct a Sample Conditioning System 
The invention also includes a method for mounting of base modules, with 
attached conditioning component module's, that provides for proper 
alignment of corresponding passages in adjacent base modules, provides the 
clamping force between adjacent base module to form fluid barriers around 
passage junctions as aforementioned, and also provides a means for 
mounting an entire Sample Conditioning System constructed by the methods 
previously described. 
The method consist of first constructing a mounting rail 148 as shown in 
FIG. 19,20,21, and 10. The mounting rail 148 slides into grooves 149 A and 
149B formed in the sides of base modules 150A, 150B, 150C, fluid barriers 
151 A, fluid barrier 151 B, fluid barrier 151C, and termination modules 
157 and 158 as shown in FIG. 20. For sake of clarity conditioning 
component module were not shown mounted on base modules 150A, 150B, and 
150C. The mounting rail maintains alignment between adjacent modules and 
in conjunction with termination modules 157 and 158 provides a method for 
exerting a clamping force between base modules thereby compressing fluid 
barrier 151A, 151 B, and 151C as required to effect sealing of base module 
and termination module passage junctions. A specific means for exerting 
the clamping force is shown in FIG. 20 although other means are known. 
In this example a first termination module 158 is retained on mounting rail 
148 by pin 155 inserted through holes 153A and 153B. A second termination 
module 157 is retained on mounting rail 148 by pin 154 inserted through 
holes 152A and 152B. A bolt 156 is threaded through termination module 157 
with its end in contact with base module 150A. By tightening bolt 156 a 
clamping force is exerted which compresses fluid barriers 151A, 151B, and 
151C as required to effect fluid sealing of base module and termination 
module passage junctions not shown, and secures the entire assembly which 
includes base modules 150A, 150B, and 150C fluid barriers 151A, 151B,and 
151C termination modules 157 and 158 and pins 154 and 155. The assembly 
160 can be mounted to a mounting surface 159 with screws 160A and 160B 
through holes 161A and 161B. 
To remove a base module from the assembly 160, bolt 156 is loosened, pin 
154 is removed, and base modules are slid from the mounting rail 148. 
Since the base modules do not perform any sample fluid conditioning 
functions they are not likely to require removal once in service. The 
conditioning component modules however can easily be removed and/or 
replaced from a Sample Conditioning System assembly by loosening and 
removing bolts 34 and 35 as seen in FIG. 10 and 12. It should be noted 
that passages not shown, formed in termination module 158 provide fluid 
communication between the base modules and external devices through 
openings such as openings 162, 163, 164, and 165 of FIG. 20 in a manner 
similar to that described for providing fluid communication between base 
module 12 and conditioning component module 11. In a manner similar to the 
method for imposing a strain in a threaded member for compensation of 
barrier material displacement, a strain can be imposed in the mounting 
rail 148, by tightening bolt 156, which will compensate for the collective 
displacement of all barrier material disposed between base modules mounted 
on the mounting rail. 
Attachment for Fluid Transport Tube The current invention also provides a 
means for attaching fluid transport tube to a device body such as a base 
module. Tubing attachments are necessary to conduct sample fluids between 
the Sample Conditioning System and external sample fluid sources or 
disposal sites. Prior art tubing attachments are a common and frequent 
source of fugitive emissions of sample fluids. The tubing attachment means 
of the current invention provides two fluid barriers in series with a 
collection passage. A collection passage serves to transport to an 
external disposal site fluids which may breach a first series fluid 
barrier. 
A second fluid barrier prevents fluids in the collection passage from 
escaping to the surrounding environment. The function of the invention's 
tubing attachment and sealing method is similar to the two series fluid 
barriers with collection passage previously described for sealing passage 
junctions between conditioning component modules and base modules. 
Multiple series fluid barriers are well known in the prior art. Examples 
are the compression ferrules utilized by Swagelock.TM., Parkers 
Hannifin.TM. and Tylok.TM.. However, the prior art does not provide means 
for preventing leakage of sample fluid to the external environment by 
collecting and transporting to an external disposal site fluids which 
breach a first fluid barrier. 
In the preferred embodiment (FIG. 22A and 22B) a circular cavity 182 is 
formed in body segment 166. Body segment 166 represents a segment of the 
body of any fluid containment device. The diameter of cavity 182 is 
reduced in four successive steps resulting in the formation of circular 
ledges 171, 172, and 174, Fluid passage 170 is in fluid communication with 
cavity 182 between ledges 172 and 174. Female threads 176B are formed in 
the inner diameter of the cavity 182 between circular ledge 174 and outer 
surface 183. A nut 168 has male threads 176A formed on its lower end. When 
assembly 186 is assembled as shown, lower ferrule 173 rest upon ledge 172, 
upper ferrule 175 rests upon ledge 174, male threads 176A of nut 168 are 
threaded into female threads 176B of cavity 182; and tube 167 extends 
through the center holes of nut 168, upper ferrule 175, lower ferrule 173 
and rests upon ledge 171. The center passage 177 of tube 167 is in 
approximate axial alignment with passage 169. 
Upper ferrule 175 and lower ferrule 173 are rigidly attached and fluidly 
sealed to tube 167. Lower ferrule 173 and ledge 172 in combination form a 
first fluid barrier for sample fluid 184. Upper ferrule 175 and ledge 174 
in combination form a second fluid barrier in series with the first fluid 
barrier. Cavity 178 and passage 170 in combination form a collection 
passage for sample fluid which may breach the first fluid barrier. Nut 168 
forces contact between upper ferrule 175 and ledge 174 and between lower 
ferrule 173 and ledge 172 which in turn retains tube 167 in the position 
shown in assembled view FIG. 22B. 
In normal service passages 170 and 169 provide fluid communication between 
body segment 166 and external fluid sources or fluid receiving sites not 
shown. Body segment 166 represents a segment of any device body which is 
utilized in the construction of a Sample Conditioning System. Should fluid 
contained in passages 169 and 177 breach the lower fluid barrier it enters 
cavity 178 then is transported by passage 170 to an external disposal site 
not shown. If body segment 166 is a segment of a conditioning component 
module, base module or termination module previously described, then 
passage 170 becomes an integral part of the Sample Conditioning System 
fluid containment network. 
Another means of operating assembly 186 is to pressurize passage 170 with 
an inert gas to a pressure equal to or slightly in excess of the fluid 
pressure in passages 169 and 177. A failure of the lower fluid barrier 
would then result in inert gas from passage 170 flowing through cavity 178 
and into passages 169 and 177 thereby preventing sample fluid contained in 
passages 169 and 177 from escaping to the surrounding atmosphere. Yet 
another means of operating assembly 186 is to evacuate passage 170 and 
cavity 178 by external vacuum means. In the event of a lower fluid barrier 
failure sample fluid entering cavity 178 will be conducted by passage 170 
to an external disposal site not shown. Should the upper fluid barrier 
fail then fluids from the surrounding environment will enter cavity 178 
and be transported by passage 170 to an external disposal site not shown. 
In any case, however, sample fluids cannot escape to the external 
atmosphere. The preferred embodiment described, assembly 186, achieves the 
desired two series fluid barriers separated by a fluid collection passage. 
While certain specific embodiments and details have been described in order 
to illustrate the present invention, it will be apparent to those skilled 
in the art that many modifications can be made therein without departing 
from the basic concept and scope of the invention. 
Further, the invention embodiments herein described are done so in detail 
for exemplary purposes only, and may be subject to many different 
variations in design, structure, application and operation methodology. 
Thus, the detailed disclosures therein should be interpreted in an 
illustrative, exemplary manner, and not in a limited sense.