Groundwater sampling device with a lift check value

A new lift check valve and groundwater sampling device using same is disclosed. The inventive device includes a body having a fluid flow bore extending therethrough and a first body end. A valve stem is sealingly disposed within the fluid flow bore and includes a first fluid flow bore extending from a first end and terminating at a disk integrally formed at a second end. The valve stem further includes a transverse bore extending therethrough in fluid flow communication with the first fluid flow bore and is moveable within the fluid flow bore between a first position in which the transverse bore is disposed without the fluid flow bore for fluid flow therethrough and a second position in which the transverse bore is disposed within the fluid flow bore to close off fluid flow through the fluid flow bore. A spring is provided to constrain the movement of the valve stem between the first and second positions including a first section fixedly attached to the disk and a second section extending perpendicularly from the first section and being receivable within an aperture formed in the valve stem. The second section is receivable within a peripheral recess formed in a base formed in the body opposite the first body. Alternativly a flared tab is provided to constraint the movement of the valve stem for use in single use applications.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to lift check valves for controlling flow and 
more particularly pertains to a new groundwater sampling devices with lift 
check values into and out of a groundwater sampling device. 
2. Description of the Prior Art 
Groundwater pollution including that from volatile organic compounds 
(hereinafter VOC) continues to be a widespread problem in need of 
remediation. In order that samples of groundwater can be obtained, devices 
known as bailers are employed. Bailers are designed for single, disposable 
use or to be reusable. Known bailers include a narrow elongate tube having 
a ball check valve disposed at a lower end. The tube is lowered into a 
groundwater monitoring well and the ball check valve allows the 
groundwater being sampled to enter the tube but blocks the sample's exit 
from the tube when full or upon withdrawal from the well. Standard 
groundwater sampling protocol requires that three volumes of well water be 
removed prior to removal of a groundwater sample. 
U.S Pat. No. 5,507,194 to Scavuzzo and Hawkins shows a known ball check 
valve that employs a ball and seat valve apparatus. While these valve 
apparatus are effective in allowing the sampled groundwater to enter the 
bailer tube, on many occasions particulates existent in the sampled 
groundwater interfere with the seating of the ball upon the seat and the 
sampled groundwater leaks from the tube. 
Once the groundwater sample is collected, the bailer must be withdrawn from 
the well and raised to the surface. Prior art ball check valves employed 
in bailers are prone to lose their seal it jarred. Upon withdrawal from 
the well it is common for the bailer to jar against protuberances or 
offset seams in the well casing (wall). The resulting loss of sample not 
only makes sampling more difficult but also can lead to biasing of the 
concentration of VOC in the water to be sampled due to the turbulence 
induced by the escaping water. This turbulence drives off VOC. U.S. Pat. 
No. 5,404,949 to Voss attempts to remedy this problem by providing for top 
and bottom surfaces on the bailer tube that will not lodge against 
irregularities on the surface of well walls. The patent to Voss however 
teaches the use ol a ball and seat valve apparatus prone to sample loss as 
described above. 
Another major problem encountered in groundwater sampling is low well water 
levels, for example, those that occur in the driest period of the year. 
Known prior art bailers will at most fill to the level of the well water 
surface. If this level is low, as for example only a few inches from the 
bottom, many samples must be taken to meet standard sampling quality 
control protocols. This problem together with the sample loss described 
above can compound quality control problems and make difficult the task of 
sampling groundwater. 
Once the groundwater sample has been collected from the well for analysis, 
it must be removed from the bailer. Known prior art bailers employing a 
ball and seat valve apparatus suffer the disadvantage of not being easily 
emptied. U.S. Pat. No. 5,507,194 to Scuvuzzo and Hawkins teaches a 
disposable bailer employing a ball and seat apparatus. The sample is 
removed from the bailer by means of a pour spout disposed at an upper end 
of the bailer tube. Means are provided to constrain the longitudinal 
motion of the ball while the bailer is emptied but the ball must of 
necessity move during this operation thereby allowing sample to spill from 
the tube. 
Thus it would be desirable to provide a valve for a groundwater sampling 
device that overcomes the deficiencies found in the prior art. It would 
also be desirable to provide a valve for a groundwater sampling device 
that reduces groundwater sample loss as the groundwater sampling device is 
withdrawn from the well. It would further be desirable to provide a valve 
that reduces sample loss due to the presence of particulates present in 
the sampled groundwater. It would also be desirable to provide a valve 
that can sample effectively at low well water levels. It would further be 
desirable to provide a valve which enables the sampled groundwater to be 
easily removed from the groundwater sampling device. It would further be 
desirable to provide a valve that is easily disassembled for cleaning. 
Finally, it would be desirable to provide a valve that is simple in design 
and easily manufactured as well as being reliable and of durable 
construction. 
As will be more fully appreciated from the description that follows, the 
valve of the present invention has several advantages ever prior art check 
valves. A major advantage is the reduction of sample loss. This is 
accomplished by means of a first seal formed between a valve stem wall and 
a fluid flow bore. The contact surface between the valve stem wall and the 
fluid flow bore is of much greater dimension than that of the ball check 
valve and is thus less likely to leak sample if jarred upon withdrawal 
from the well during sample recovery. 
Another major advantage of the valve of the present invention over prior 
art valves used in bailers is its ability to collect adequate samples even 
in situations where the water surface in the well is near the well bottom. 
This can be accomplished by alternately raising the bailer to shut the 
valve and then rapidly lowering the bailer below the water surface, 
thereby opening the valve and allowing liquid to enter the bailer. Thus, 
low water level wells can be quickly emptied with few withdrawals of the 
bailer from the well to achieve standard quality control protocols. 
The valve of the present invention allows for controlled emptying from the 
bottom of the recovered bailer with a minimum of agitation, turbulence or 
likelihood of spills. This minimizes loss of VOC due to agitation that 
maintains sample integrity as well as exposure of personnel to spills of 
hazardous material. 
Another advantage provided by the valve of the present invention is that 
cleaning and reuse of the valve can be easily accomplished if desired by 
removing the valve stem from the valve by simply removing a spring, pin or 
clip used as a stem retaining means. In addition the valve is sturdy, 
durable and easy to fabricate without sacrificing maximum potential flow 
rate into the bailer. 
Finally the valve of the present invention reduces problems posed by 
particulates in the sample. A disk has a machined tapered edge that 
sealingly mates with a body tapered edge to prevent most particulates from 
being lodged in a second seal formed between the tapered edges. The 
machined surfaces are formed to direct particulates away from the second 
seal. 
SUMMARY OF THE INVENTION 
The present invention is a lift check valve for controlling the flow into 
and out of a groundwater sampling device. 
The valve includes a body having a fluid flow bore extending therethrough 
and a first body end. A valve stem is sealingly disposed within the fluid 
flow bore and includes a first fluid flow bore extending from a first end 
and terminating at a disk integrally formed at a second end. The valve 
stem further includes a transverse bore extending therethrough in fluid 
flow communication with the first fluid flow bore. The valve stem is 
moveable within the fluid flow bore between a first position in which the 
transverse bore is disposed at least slightly above the fluid flow bore to 
allow for fluid flow therethrough and a second position in which the 
transverse bore is disposed within the fluid flow bore to close off fluid 
flow through the fluid flow bore. 
A means for constraining the movement of the valve stem within the fluid 
flow bore between the first and second positions is provided including a 
spring having a first section fixedly attached to the disk and extending 
through the first fluid flow bore and a second section extending 
perpendicular to the first section and extending through an aperture 
formed in the valve stem. Alternate means include a pin extending 
perpendicularly through the valve stem at the first end, a clip disposed 
at the first end and a flare or tab formed at the first end. The body 
further includes a base of greater peripheral dimension than the body 
disposed opposite the first body end and having a peripheral recess formed 
therein, the peripheral recess adapted to receive the second section of 
the spring, the pin, the clip or the flare or tab. Alternatively, the 
means for constraining the movement of the valve stem includes a stopping 
member disposed within a bailer tube interior, the stopping member 
determining the first position and obviating the need for a peripheral 
recess. 
The body further includes a body tapered edge extending downwardly and 
outwardly, the body tapered edge being formed at the first body end. The 
body tapered edge matingly and sealingly receives a tapered edge extending 
downwardly and outwardly formed on the disk. 
A means for sealingly mounting the lilt check valve to a groundwater 
sampling device is provided. The groundwater sampling device includes a 
tube having an open end and a bottom end. The bottom end includes a 
threaded bore formed to threadingly and sealingly receive the lift check 
valve. 
These together with other objects of the invention, along with the various 
features of novelty which characterize the invention, are pointed out with 
particularity in the claims annexed to and forming a part of this 
disclosure. For a better understanding of the invention, its operating 
advantages and the specific objects attained by its uses, reference should 
be had to the accompanying drawings and descriptive matter in which there 
is illustrated preferred embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference now to the drawings, and in particular to FIGS. 1 through 3 
thereof, a new lift check valve embodying the principles and concepts of 
the present invention and generally designated by the reference numeral 10 
will be described. Materials typically include stainless steel or 
Teflon.TM. and similar cholofluorocarbons for reusable applications or 
plastics such as polyethylene for single use applications. 
More specifically, it will be noted that the lift check valve 10 comprises 
a body 11 having a fluid flow bore 23 extending therethiough and a first 
end 18. A valve stem 13 is sealingly disposed within the fluid flow bore 
23 and includes a first fluid flow bore 14 extending from a first cnd 15 
and terminating at a disk 12 integrally formed at a second end 16. The 
valve stem 13 further includes a transverse bore 17 extending therethrough 
in fluid flow communication with the first fluid bore 14. The valve stem 
13 is moveable within the fluid flow bore 23 between a first position in 
which the transverse bore 17 is disposed without the fluid flow bore for 
fluid flow therethrough and a second positioin in which the transverse 
bore 17 is disposed within the fluid flow bore 23 to close off fluid flow 
through the fluid flow bore 23. 
With reference to FIG. 1 the groundwater sampling device 30 includes a tube 
31 having an open end 41, a bottom end 42 and an interior 43. The lift 
check valve 10 sealingly and threadingly mounts to the bottom end 42 that 
includes a threaded bore 32. 
With reference to FIG. 2 the valve stem 13 is shown disposed within the 
body 11. The lift check valve 10 includes a valve stem 13 having a first 
end 15 and a disk 12 disposed at a second end 16. The body 11 includes a 
base 22 having a greater peripheral dimension than the body 11. The body 
also includes threads 24 formed thereon between the base 22 and a first 
body end 18. Also shown is a tab 34 formed from the valve stem first end 
15 by cutting a section of the valve stem first end 15 and bending it out 
and away from the valve stem first end 15. 
With reference to FIG. 3 the valve stem 13 includes a first fluid flow bore 
14 that extends from the first end 15 and terminates at the disk 12 
disposed at the second end 16. A transverse bore 17 extends through the 
valve stem 13 and is in fluid flow communication with the first fluid flow 
bore 14. In a first position the transverse bore 17 is disposed without 
the fluid flow bore 23 and fluid flow therethrough is allowed In a second 
position the transverse bore 17 is disposed within the fluid blow bore 23 
to close off fluid flow through the fluid flow bore 23. 
With continued reference to FIG. 3 an alternative means for constraining 
the movement of the valve stem between the first and second positions is 
shown including a spring 35 including a first section 36 fixedly attached 
to the disk 12 and extending through the first fluid flow bore 14. A 
second section 37 extends perpendicularly from the first section 36 and 
extends through an aperture 38 formed in the valve stem 13. A peripheral 
recess 33 formed in the base 22 receives the second section 37. 
With further reference to FIG. 3 the first body end includes a body tapered 
edge 21 that extends downwardly and outwardly and matingly and sealingly 
receives a tapered edge 19 formed on the disk 12. 
In use the groundwater sanipling device 30 is lowered into a well to 
collect a sample of groundwater. When liquid is encountered buoyant and 
other forces move the valve stem 13 to the first position thereby allowing 
for entry of groundwater into the tube interior 43. When fluid forces 
equalize, the valve stem 13 moves to the second position thereby closing 
off fluid flow. Valve stem 13 cannot be unseated by lateral forces due to 
the close tolerance between valve stem 13 and fluid flow bore 23. 
Furthermore a large upward force exrted upon the valve stem 13 is required 
before the transverse bore 17 is disposed above the tapered body edge 20 
and fluid flow from the tube interior 43 is allowed. 
As the tapered edge 19 matingly and sealingly meets the body tapered edge 
21, fluid velocity increases between the two surfaces and moves any 
existent particulates away from the mating surfaces. Additionally, 
particulates are directed away from the valve stem 13. The particulates 
thus directed reside in a volume of the tube interior 43 formed by the 
elevation of the lift check valve 10 from the bottom end 42 and away from 
the seal formed by the body 11 and the valve stem 13. 
Upon being withdrawn from the well the groundwater sampling device 30 is 
emptied by pressing the valve stem 13 onto the inside wall of a receiving 
container such that transverse bore 17 rises above the body tapered edge 
21 to establish fluid flow communication In this manner the groundwater 
sampling device 30 can be partially or totally emptied. The flow is 
controlled by the position of the valve stem 13 relative to the transverse 
bore 17 and can be shut off at any moment to fill multiple sample 
receiving containers. 
To clean the lift check valve 10 the second section 37 of the spring 35 is 
wholly fit into the first fluid flow bore 14 and the valve stem 13 is 
removed from the groundwater sampling device 30. In the case of the valve 
comprising the tab 34, it is contemplated that the sampling device would 
be designed for single use and thus there would be no need to remove the 
valve stem 13 from the first fluid flow bore 14. 
As to a further discussion of the manner of usage and operation of the 
present invention, the same should be apparent from the above description. 
Accordingly, no further discussion relating to the manner of usage and 
operation will be provided. 
With respect to the above description then, it is to be realized that the 
optimum dimensional relationships for the parts of the invention, to 
include variations in size, materials, shape, form, function and manner of 
operation, assembly and use, are deemed readily apparent and obvious to 
one skilled in the art, and all equivalent relationships to those 
illustrated in the drawings and described in the specification are 
intended to be encompassed by the present invention. 
Therefore, the foregoing is considered as illustrative only of the 
principles of the invention. Further, since numerous modifications and 
changes will readily occur to those skilled in the art, it is not desired 
to limit the invention to the exact construction and operation shown and 
described, and accordingly, all suitable modifications and equivalents may 
be resorted to, falling within the scope of the invention.