US3390580A

US3390580A - Sample systems

Info

Publication number: US3390580A
Application number: US522757A
Authority: US
Inventors: L B Taylor
Original assignee: L.B. Taylor
Current assignee: Lb Taylor
Priority date: 1966-01-24
Filing date: 1966-01-24
Publication date: 1968-07-02
Anticipated expiration: 1985-07-02

Description

July 2, 1968 L B TAYLOR 3,390,580

SAMPLE SYSTEMS Filed Jan. 24, 1966 2 Sheets-Sheet l INVENTOR.

LECTQ lor BY July 2, 1968 B TAYLOR 3,390,580

SAMPLE SYSTEMS Filed Jan. 24, 1966 2 Sheets-Sheet 2 INVENTOR.

3,390,580 SAMPLE SYSTEMS L. B. Taylor, Rte. 3, Box 145, Snyder, Tex. 79549 Filed Jan. 24, 1956, Ser. No. 522,757

14 Claims. (Cl. 731-422) ABSTRACT F THE DISCLOSURE A sampling system for withdrawing fluid samples from a conduit consisting of a double acting solenoid operated pump and a flask for storing the fluids sampled., In addition another smaller llask may be utilized for transporting the sampled lluid to an analysis location. The pump features two solenoids, one for moving the armature in each direction the armature being provided with two suitably located magnets. The two pump pistons extend beyond the armature into the two pump cylinders. The receiving ask is constructed of nonmagnetic material in the form of a cylinder closed at both ends save for suitable filling and emptying ports. A magnetized piston in the cylinder separates the sampled material from that there before. The magnetic properties of the piston are utilized to either provide an indication of its position or for driving it to one end of the cylinder or the other. A perforated piston can likewise be moved magnetically for stirring purposes. The second flask is similar in construction to the first but is smaller.

This invention relates to an apparatus for sampling fluids and pertains more particularly to an app-aratus for automatically collec-ting, over a predetermined time period, a continuous composite or average fluid sample from a pipe line or the like. The time interval between each integral of sample, as well as the quantity of the sample, may be set at a predetermined rate to provide a composite sample of the flowing stream so as to enable a laboratory determination of the quality and composition of the sampled iiuid.

Another aspect of this invention relates to a sample receiver with a novel mixing device that is arranged in conjunction with the sample receiver that will overcome any possible settling out of heavy components. The mixing device is magnetically actuated through external means so as to enable the laboratory to withdraw a small quantity of sample from the receiver that is accordingly representative of the entire contents of the sampled fluid contained within the receiver. The novel receiver further provides a unique magnetic indicating means that enables one to determine the fluid content level of the receiver when the sample being taken is a liquid.

This invention further provides a novel sampling method that embraces the steps of collecting a predetermined number of integral sample portions over a predetermined interval of time and subsequently transferring a portion of the sample into a smaller size flask for laboratory analysis.

Also of importance is the provision of a novel valve arrangement used in conjunction with the receiver that enables one to readily charge or withdraw a sample from the container with a minimum of effort while avoiding contamination.

It is accordingly an object of this invention to provide a novel pump such as before mentioned that will move a predetermined amount of fluid during a predetermined time cycle.4

Another object of this invention is to provide a novel sample receiver that precludes purging prior to sampling.

Another object of this invention is to provide a novel nited States Patent O ice means of determining the iluid contents of the novel sample receiver.

Another object of this invention is to provide a novel mixing device that may be used in conjunction with the novel sample receiver,

Another object of this invention is to provide a novel combination of a pump, receiver flask, and laboratory ask arranged in a novel manner that permits a predetermined amount of metered sample to be rapidly obtained from the system for laboratory analysis.

Still another object of this invention is to provide a novel method of obtaining a representative sample from a tluid system.

A still further object of this invention is to provide a unique method of sampling that includes transferring a predetermined amount of fluid sample at predetermined time intervals into a main sample receiver that may subsequently deliver a uniform portion of the sample to a smaller receiver for laboratory analysis.

A still further object of this invention is to provide a novel valve arrangement in conjunction with the receiver that simplifies obtaining the sample and enables rapid withdrawal of -portions of the sample from the receiver.

These and other objects of the instant invention will become apparent from the following description of the invention taken in conjunction with the drawing, wherein:

FIGURE l is a diagrammatic View, partly in section, of one embodiment of the sample receiver and pump means, taken along line 1 1 of FIGURE 2.

FIGURE 2 shows an end view of the pump means of FIGURE 1. i

FIGURE 3 is an enlarged sectional view of the novel valve means used in conjunction with the receiver of FIGURE l.

FIGURE 4 is a partly diagrammatic view With some parts shown in section, of another embodiment of the sample system.

In general, the drawing shows in FIGURE l a pump indicated by numeral 12. The pump 12 is operatively attached to a system which is desired to `be sampled, as for example, iluid carrying pipe line 10 at valve 14. The pump 12 is preferably connected to a sample receiver or llask 26 by inlet valve arrangement 24, and to the pipe line by the return purge valve 29.

Referring now in detail -to the drawings, there is seen connected to valve 114 of pipe line 10 a conduit having a T-connection 15 followed by a Y-connection 13 that delivers the Huid sample into

inlet connectons

17 and 17 of double acting pump 12.

The pump 12 is comprised of a central motor portion including a cylindrical housing 31 that carries solenoid coils 28, 28' peripherally thereabout and an armature made up of

iron slugs

30, 30 and non-ferrous slug 32.

Couplings

23 and 23 threadedly attach each end of housing 31 to the pump heads 43 and 43', which in turn contain the valves and pistons that move the sampled iiuid.

A hollow bolt and connection 17 is connected to conduit 1l which is attached to the Y-connection 13 and communicates with pumping cavity 18 through the inlet check valve 16 located in the pumping cavity 18. The piston 34 is reciprocatingly received in close tolerance relationship within pumping cavity 18 and provides a pumping action as it reciprocates within the chamber since inlet valve 16 and outlet valve 20 are one way check valves that permit one way flow through the pum-p heads 43, A hollow nut 19 leads into outlet connection at conduit 22 which is essentially identical to the similar nut at fluid connection 17 except for being larger in diameter to permit assembly of the two check valves. Conduit 22 3 joins conduit 22 in a Y-connection indicated by number 21.

The motive power for piston 34 is provided by the before mentioned iron slugs 30 in conjunction with the non-ferrous portion 32 which jointly make up an armature comprised of

elements

30, 32, and 30'. The armature is moved or actuated by solenoids 28 and 28' which are essentially a wire wound coil peripherally surrounding the non-magnetic cylinder 31. Energization of the solenoids at a predetermined time cycle will accordingly impart a movement to the armature to provide a pumping action having a cycle of operation that will coincide with that of the energization of the solenoids.

Control unit 4 provides the solenoids 28 and 2S with the above mentioned timed cycle or impulse of electrical energy. The control unit may be conveniently located in proximity to the pump 12 and provided with a source of

current S. Conduits

2, 3, 2', and 3' electrically connect the solenoid coils to the control unit.

Rigidly attached to each armature slug 30 and 30' is the before mentioned

pistons

34 and 34 which carries a grooved end portion to accommodate O-ring 37 to fluid seal the piston 34, pumping cavity 18, and void 38 from each other.

The void 38 is filled with fluid and communicates with a similar void in the ,opposite action or pump through adjustable passageway 36, to thereby provide for a cushioned stop which accordingly eliminates bumping or shock as would occur should the armature abut the main body or

pump heads

43, 43 of the pump 12. This second void is not seen since the armature is at the extreme end of its travel or in abutting relationship with the pump head 43', hence this second void has been displaced or filled by the armature, as will be void 38 upon travel of the armature to the opposite extreme end .of its stroke. Thus it is seen that the fluid contained within the voids is transferred from one void to the other with each stroke of the armature.

The size of the passageway 36 is controlled by reduced rod portion 40 which is adjustably mounted in the main pump head 43 by a threaded counter-bore that receives a like threaded rod portion 41 carrying a lock nut thereon. The passageway is drilled through as seen at 36 and may be 4provided with a larger counter-bore as at 39 to increase the rate of response of the armature and piston arrangement. The opposite pump head carries a similarly threaded adjusting rod 42 that extends up to or beyond the face of the armature and received in passageway 36. The rod 42 provides a second stop for the second slug 30. Except for the construction of the already discussed rod 42, the remaining features of the pump head 43', are identical to the similar pump head 43, and accordingly will not be discussed in further detail.

Return conduits

22 and 22 are interconnected at Y- connection 21. A T-connection 25 provides a bypass back to T-connection 15 and located therebetween is a one-way check valve 44 that is resiliently biased to provide flow in the direction of the arrow. A quick disconnect comprised of union 27 connects the pump outlet to the sample reservoir or flask 26.

The sample flask comprises a cylindrical container 26 made of non-magnetic material and having a valved inlet at end 50 and a valved outlet at end 51. Grooved piston 46 carries O-

ring

47 and 47 peripherally located thereabout and divides the flask into two sealed

chambers

48 and 48. The piston is adapted to slide from wall 50 to wall 51 as the chamber 48 is lled. The piston is magnetized so as to form a magnet having a polarity as indicated in the drawing. A stop 60 prevents damage to any portion of the valve 24 that may extend into the chamber 48'.

Located within sealed chamber 48 is a perforated plate 49 that is slidably received within the cylinder 26 and within chamber 48. The plate is fabricated from magnetic material and may be caused to travel longitudinally between wall 5i) and piston 46 upon application of an external magnetic field.

Conduit 77 is shown interconnecting each of the

chambers

48 and 48 through a valve 78. This conduit and valve arrangement permits the piston to be moved from wall 51 to wall 50 in order to prepare the flask for a new sample while avoiding the necessity of discharging the old sample from the container. The piston is moved by an external magnetic force, such as a large solenoid coil placed peripherally about the flask, and moved from one extremity to the other while carrying the piston 46 along with the coil through magnetic attraction.

Located externally of the flask 26 is a magnet 52 mounted for longitudinal movement along the outside of the wall of the flask. The poles of magnet 52 are opposite in polarity to the piston 46 and hence the magnet 52 will tend to follow the piston thereby giving an indication of its position and hence the relative volume of the chambers. The magnet 52 may be located on a detachable track, or permanently mounted in a low friction grooved support extending longitudinally and adjacent the flask. The specific support means employed for the magnet are not shown in the drawing.

FIGURE 3 shows the details of the valve 24 that is located in each end wall 50, 51 of the flask. The valve arrangement is comprised of a ball-check valve 70 having a sealed stem 68 that upsets the ball from the seat when engaged therewith. The Valve body 62 is threaded as at 69 and incorporates an O-ring seal 64' to provide a positive seal between the valve body and the flask. The valve body includes a threaded counter-bore that provides a chamber in which is housed the ball 70 and spring 74. The threaded keeper 72 maintains the spring in compression and forces the ball against its seat. Threadedly mounted in the body of the valve is a valve head 60' having drilled

passageways

65 and 76 provided therein. Passageway 76 is counter-bored to receive the valve stem guide plug 67 and O-ring seal 66 which maintains the stem and plug in fluidtight relationship to the remainder of the valve parts. A conventional valve 63 may optionally be provided at the end of passageway 65 in order to maintain

passageways

65 and 76 filled with sample fluid, if desired, thus eliminating the need for filling these passageways with mercury prior to withdrawing a portion of the sample for testing, as is known in the art.

Located in wall 51 of flask 26 is a second valve 24' identical to valve 24. A safety valve 63 attaches to a quick disconnect 27 which leads to sample return valve 29 in the main line 10.

Looking now to the embodiment of FIGURE 4, there is seen therein, a sample flask arrangement adapted to be used in lieu of the before described sample flask 26 of FIGURE l. FIGURE 4 shows a safety valve 163 operatively connecting sample flask 126 to the Y-connection 25, which delivers fluid therethrough in accordance with the embodiment of FIGURE 1. Return valve 163 is operatively cannected between the flask 126 and the pipe line 10. Valve interconnects the laboratory flask 226 with the stationary sample flask 126. The stationary sample flask 126 is provided with magnetic piston 146 having a peripheral groove thereabout to receive O-rings 147 and 147' located therein in sealing relationship with the inside wall of the sample flask 126. The piston 146 divides the sample flask 126 into two

chambers

148 and 148.

Located within sealed chamber 148 is a perforated plate 149 that is slidably received within the cylinder 126 and within the chamber 148. The plate is fabricated from magnetic material and may be caused to travel longitudinally between the wall 150 and the piston 146 upon application of external electrical current to the solenoid coil 128 located about the outer periphery of the sample flask 126. The relationship of the piston 146 and the perforated plate 149 to the sample flask 126 is identical with junction with FIGURE l.

The laboratory sample flask 226 is adapted to be connected to the stationary flask 126 by the quick disconnect 116. The laboratory sample flask is comprised of an elongated tubular vessel having recessed end plates 251 and 250 integrally attached to the sidewall 226 so as to provide

tubular extensions

268, 269 in which is housed inlet and

outlet valves

263 and 264 respectively, adjacent the end walls 250 and 251. The tubular extension is apertured as at 266 and 288 to provide access to the before mentioned valve stems by inserting a suitable valve stem handle therethrough. Each valve stem 265, 267 is preferably splined at the free end thereof in order to provide a means by which a valve stem handle or tool may be inserted through the apertures to thereby mate with the Spline and accordingly actuate the valve between open and closed position. The

valves

263 and 264 are suitably recessed within the tubular extension so as to protect the valve mechanism from damage or from inadvertently being opened after the sample has been taken.

Located within the laboratory flask 226 is a magnetically actuated piston 246 slidably received within laboratory flask 226 so as to be able to reciprocate from wall 250 to wall 251, in a manner as previously discussed in conjunction with the

flask

26 and 126.

The grooved piston 246 receives O-ring 247, 247' about the periphery thereof to provide a sealed relationship between the piston and the flask wall.

The outlet valve 264 of the flask 226 is provided with quick disconnect 166 adapted to be connected to laboratory analyzing equipment.

A graduated vessel 229 may operatively be connected to the laboratory flask 226 by fluid conduit 118 when it is desired to obtain a specific sample size.

Operation Referring to FIGURE 1, the pump and receiver are disclosed as being operatively attached to each other while taking a sample from pipe line 10. The sampled fluid flows through the main sample cut-off valve 14, past T-connection 15, to Y-connection 13 where the flow splits to provide each

inlet connection

17 and 17 of the pump 12 with a fluid source. The fluid is forced into pumping cavity 18 through the hollow bolt at 17 and past one-way check valve 16 as it is moved by piston 34 past the outlet connection and hollow bolt at 19 into fluid conduit 22. The fluid entering the opposite pump head 43 at connection 17 follows the same type flow path since both pump heads are identical except for the control means 41 and 42. The

fluid return lines

22 and 22 are brought together at Y-connection 21 where the fluid then flows to the sample flask 26 through T-connection 25, quick disconnect 27, safety valve 63, and check valve 24.

The rate of response of the pump piston 34 to the applied current of solenoids 28 is regulated by the adjustable orifice 39, 40 located in passageway 36. The response rate of the armature to the current applied to

solenoids

28 and 28 is increased as the rod 40 is Withdrawn from the counter-bore 39 which forms part of the orifice or adjustable passageway. The length of the pump stroke is controlled by adjustable rod 42 which provides a cushioned stop for the armature. As rod 42 is removed from its bore, the stroke of the pump is increased, and conversely, as the rod is extended into the pump head, the length of the stroke is decreased. Hence rods 41 and 42 provide a means by which both the rate of response and the length of the stroke of the piston may be adjusted to control the pumping time during a cycle as well as the integral sample size that is transferred from the pipe line into the flask 26.

The rate at which the armature is actuated, or the number. of strokes per minute made by the pump, is governed by control unit 4, which is adapted to energize the

coils

28 and 28 with a signal that is sent through the

electrical conduits

2, 2', 3, and 3.

When the fluid sample first begins to enter flask 2.6, piston 46 and agitator 49 will be adjacent wall 50 in order to present the smallest possible void between the piston and wall, thus minimizing contamination. As the pump fills the flask with fluid, the piston 46 will move towards the opposite wall 51 as the piston is displaced by the introduced fluid. Should the flask continue to be fllled until the piston abuts wall 51, and the pump continue to oper'a'te after the flask is completely full, the bypass at 44 will then open due to the increased pressure head to thereby recirculate the fluid back through the .pump system, thus obviating damage to the system. Furthermore, should a valve downstream of the pump inadvertently be left closed, the bypass 44 will recirculate the pumped fluid.

The magnet 52, since it is slidably placed in a track, or the like, and located longitudinally along and adjacent to the flask 26, will tend to follow the piston since the wall of flask 26 is fabricated from non-magnetic material. The location of magnet 52 along the flask 26 indicates the position of piston 46, and accordingly indicates the amount of fluid that has entered the flask. The magnet may alternatively be placed in a channel or mounted upon a non-metallic rod.

After the sample has been obtained in the flask 26, the line valves 14 and 29, and safety valves 63, 63' are closed and the flask is disconnected at 27, 27 from pipe 1f) and the pump 12, whereupon an empty flask may then be placed in service for the newly filled flask.

When the laboratory is ready to withdraw a portion of the fluid contained in the flask 26, a suitably excited coil may be placed peripherally about flask 26 and moved longitudinally up and down the flask, thereby carrying agitator 49 with it through magnetic attraction between the coil and agitator, thus mixing the sample contained in the flask.

When it is desired to return the flask 26 to service, valve '78 is opened and the excited coil (not shown) again placed about the flask and moved so as to place the piston 46 adjacent wall 59. The valve 78 is then closed and the flask is again ready to receive a sample.

ln the embodiment illustrated by FIGURE 4, the flask 126 is preferably permanently installed adjacent a system to be sampled; as for example, a fluid carrying pipe line 10. Fluid conduit 25 operatively connects the system to a pump means 12 such as seen in FIGURE l. After the sample flask 126 is filled with fluid from the conduit 10, the solenoid coil 128 may be suitably excited and moved longitudinally of the flask so as to move the perforated plate 149 between end walls 150 and 151 by the magnetic force exerted by solenoid coil 128 in order to blend the contents of the flask. Thereafter,

valves

110, 263, and 264 are opened so as to ll laboratory sample flask 226 with a homogeneous fluid sample from chamber 148. Transfer of liquid from chamber 148 into chamber 248 may be accomplished by using solenoid 128 to magnetically attract and move the barrier or piston 146 toward wall 150 thereby displacing the fluid from chamber 148 whereupon the fluid will flow through valve 110, quick disconnect 112, fluid conduit 114, T-connection at 261, quick disconnect 116, valve 263, and hence into chamber 248 thereby displacing piston 246 until it abuts wall 250. After filling sample flask 226,

valves

264 and 263 are closed by using a suitable valve handle that mates with valve stem 265, 267 through

apertures

266 and 268. Valve is then closed, valve 178 opened and piston 146 returned to wall 150 through the means of the magnetic attraction of solenoid 128. Valve 178 is then closed and

valves

163 and 163 opened whereupon the sample flask 126 begins to collect another fluid sample from fluid conduit 10 in accordance with the fluid flow from the double acting pump.

The action of the perforated plate 149 against the inside wall of the chamber 126 will remove or scrape any viscous material therefrom which will subsequently enter into solution with the remaining fluid in the chamber 148 as the uid is agitated by the mixer 149. The squeegee like action of the O-rings 147, 147' will remove any remaining uid particles from the wall to accordingly present a clean chamber to the next incoming sample.

Where a predetermined quantity of iiuid is desired to be transferred from flask 126 of FIGURE 4 into the laboratory iiask 226, a graduated cylinder or burette 229 may be attached to quick disconnect 166 to enable a measured quantity of iiuid to be displaced from chamber 24d' by the equivalent quantity of sampled liuid entering chamber 24S. Hence, the volume of iiuid transferred to the burette is substantially equal to the volume of liuid transferred to laboratory flask 226.

Accordingly, while particular embodiments of this invention have been shown and described in detail herein, it will occur to those skilled in the art that various changes and modifications can be accomplished without departing either in spirit or scope from the invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A sampling device including a double acting pump and a ask, iiuid conduits adapted to interconnect said pump and said flask to a liuid system to be sampled, said liask having opposed inlet and outlet ends connected by a flask wall, barrier means slidably located within and in sealing relationship with said ask wall and being movable from one to another said opposed ends, a check valve located in each said end having a spring biased ball check valve that normally permits ow in a single direction, means for selectively foncing said valve open to permit tlow in an opposite direction to enable extraction of said sample, said fluid conduits including a branched inlet conduit for delivering uid from the system to each action of said pump, a `branched return outlet conduit for delivering fluid from said pump to said flask, and overload bypass means interconnecting the last said conduit with said inlet conduit.

2. The device of claim 1 wherein said flask is cylindrical, movable magnetic sensing means adjacent the outer container wall, said barrier means including a piston comprised of a magnet, said flask being fabricated from a nonmagnetic material, whereby; said sensing means locates said piston to thereby gauge the amount of sample in said flask.

3. The device of claim 2 wherein said opposite end Walls are connected together by a fluid carrying conduit having a valve therein, whereby; said piston is magnetically movable from one to an opposite said end wall in response to a magnetic force applied externally of said wall.

4. The device of claim 2 further including a magnetic perforated plate mounted for movement inside said wall and between said piston and said inlet end, whereby; said plate may be moved from said piston to said inlet wall in response to an external magnetic force to thereby agitate and mix the contents of said ask.

5. The device of claim 1 wherein said double acting pump includes a non-magnetic cylinder having opposite ends and an armature slidably located therein, solenoid coils located peripherally about said cylinder to impart translatory motion to said armature longitudinal of said cylinder upon energization of said coils, a pump head carried by each end of said cylinder and including an inlet check valve, an outlet check valve, a pumping cavity, and a piston sealingly and movably located in said cavity and operatively attached to said armature, said branched inlet conduit adapted to be connected at said inlet valve, said branched outlet conduit adapted to be connected at said outlet valves, whereby; alternate energization of said coils impart reciprocating motion to said pistons to move liuid from said system to said flask.

6. The apparatus of claim 5, and further including means forming an aperture through said armature, means forming an adjustable `rod mounted in each pump head and aligned with the first said aperture, each said adjustable rod extending into said armature aperture 'at an extreme end of travel of said armature to thereby provide a iluid Icushioned stop.

7. The apparatus of claim 6 wherein one said adjustable rod has a reduced end portion so as to provide an adjustable orifice in conjunction with said armature aperture.,

8. The invention of claim 1 wherein said check valve further includes a threaded base including a first passageway for housing said ball and spring, a body having a second passageway and received in said threaded base, a valve stem retainer received in said body and having means forming a centrally located aperture, a valve stern mounted for movement in and aligned with said iirst and second passageway and said aperture, uid sealing means between said base, body, retainer, and stem, and a lateral passage-way connecting said second passageway and forming an inlet means under normal operation as a check valve and forming an outlet means when said ball is upset by said stem.

9. A sampling system including iluid moving means connected to a liuid source to be sampled in a flask, iiuid conduits adapted to connect said ask to said uid movin-g means, said liask having opposed ends connected by a non-magnetic cylindrical wall, inlet means located in one said end and outlet means located in an opposed said end, magnetic piston means slidably located within and in sealing relationship with said cylindrical wall to form a first and second chamber, and means `for movin-g said piston from one to the other said opposed ends to thereby enable said iiuid moving means to ll said lirst chamber with liuid while displacing said piston from the inlet end to the -outlet end; magnetic sensing means slidably located adjacent to and externally of said flask and movable in the same plane and direction as said piston for indicating the displacement of said piston from said inlet end, a perforated agitator slidably received in said first chamber whereby movement imparted to said agitator between the limits of said piston and said inlet wall will mix the iiuid contents of said lirst chamber, and magnetic means for moving the agitator.

10. The device of claim 9 including a valve and a second flask;

means, including the last said valve, connecting said second flask to the first recited ask;

said second liask having end walls interconnected by a flask wall;

barrier means slidably located in sealing relationship Iwith said second iiask to thereby reciprocate between said end walls, whereby;

a laboratory sample may be transferred from said rst ask into said second iiask by moving the first said barrier means in a direction to provide flow through the last said Valve and into said second iiask.

11. A pump for use in sampling system comprising:

a non-magnetic housing having spaced detachable pump heads at each extremity; a pair of spaced solenoid coils peripherally wound about the outer periphery of said housing; an armature slidably received inside said housing and including two magnetic slugs spaced apart and integrally attached to a non-magnetic slug to thereby form a unitized armautre body; said armature having a length that is less than the length of the housing portion separating said pump heads from each other; one said magnetic slug being mis-aligned with one nearest adjacent said solenoid;

a pumping cavity centrally aligned with said pump head and said armature to form a cylinder that is adapted to receive a piston;

a piston slidably received in sealed relationship with said cylinder and adapted to reciprocate therein, means rigidly fastening said piston in each pump head pumping cavity to the nearest adjacent said magnetic slug; inlet and outlet check valve means arranged in each said pump head and in Huid communication with said cavity to provide for one way flow through said pumping cavity at the free end of said piston;

a passageway longitudinally through said armature Huid connecting each extremity of said housing at said pump head; a rod adjustably mounted in each said pump head andaligned with said passageway, said rod having a diameter to permit close tolerance lit with said passageway; whereby: electrical energization of said solenoids causes longitudinal movement of said armature to thereby impart reciprocal motion to said piston and to thereby move a fluid through said pump heads, and; said rods cooperate with said passageway to form an adjustable fluid cushioned stop therewith.

12. A method of transferring a fluid from a pipeline or the like into a sample ask comprising:

(a) transferring a predetermined amount of fluid sample at a predetermined rate from said pipeline into a first flask;

( b) magnetically moving an agitator thus agitating the transferred sample to thereby provide a homogeneous fluid sample representative of the average fluid conditions of said flask;

(c) magnetically moving a piston to move a portion of the fluid from said first flask into a second flask to thereby provide a sample size suitable for laboratory determination;

(d) magnetically moving a second piston thus removing the contents of said second flask for laboratory analysis.

13. The method of sampling a fluid system, the steps comprising:

(a) transferring a predetermined amount of sample at alconstant rate from said system to a irst flask;

(b) agitating the accumulated sample in said flask to provide a homogeneous fluid sample representative of the average fluid contained in said system during Step (21);

(c) withdrawing a portion of the fluid from the flask to provide a sample for laboratory analysis,

(d) providing said flask with an internal magnetically movable wall to thereby form a chamber Ihaving a variable volume equal to the volume of sample accumulated at a given time interval;

(e) transferring said withdrawn accumulated sample from said flask to a second flask;

(f) providing said second flask with a movable wall that maintains the volume of said second flask equal to the volume of the withdrawn fluid, whereby;

(g) said second ask may be used to obtain a sample from said first ask for laboratory determination.

14. The method of claim 13 and further including the steps of magnetically moving the movable wall of said first and second flask by an external magnetic field.

References Cited UNITED STATES PATENTS 2,260,419 10/1941 Wrightsman 73-422 2,446,657 8/1948 MacLeod et al 92--5 2,636,387 4/1953 McKinney 73-422 2,637,211 5/1953 Norman 73-422 3,282,219 1l/1966 Blackwell et al. 103-53 DAVID SCHONBERG, Primary Examiner.

S. C. SWISHER, Examiner.