US2974071A

US2974071A - Line cleaning process

Info

Publication number: US2974071A
Application number: US399492A
Authority: US
Inventors: Frank E Morris
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-12-21
Filing date: 1953-12-21
Publication date: 1961-03-07
Anticipated expiration: 1978-03-07

Description

March 7, 1961 F. E. MORRIS 2,974,071

LINE CLEANING PROCESS Filed Dec. 21, 1953 3 Sheets-Sheet 1 FRANK E. MORRIS 90 Di sy H G 7 9/ ATTORNEY.

March 7, 1961 Filed Dec. 21, 1953 F. E. MORRIS LINE CLEANING PROCESS 3 Sheets-Sheet 2 FRANK E. MORRIS INVENTOR.

vBY 5/ ATTORNEY.

March 7, 1961 F. E. MORRIS LINE CLEANING PROCESS 3 Sheets-Sheet 3 Filed Dec. 21, 1953 m oE . mowmwkoiou on FRANK E. MORRIS SUPPLY Ll/Vf J 1 V TOR. I BY ATTORNEY.

Unitgd SW68 P ent LINE CLEANING PROCESS Frank E. Morris, 4435 NE. Prescott St., Portland, Oreg.

Filed Dec. 21, 1953, Ser. No. 399,492

8 Claims. (Cl. 134-21) My invention relates to providing improvements in line cleaning and freeing process for use in cleaning fuel oil supply, return and vent lines, plumbing waste lines and lines of all categories and uses which are subject to clogging by reason of the accumulation of residues formed from the intermingling of oil products, gasoline, water or vapor or condensation Within said lines which gradually create a sludge format-ion resulting in a blocking and restriction of said lines.

One object of my invention is to provide a method of cleaning and freeing fuel oil supply, return and vent lines and plumbing waste lines which are ordinarily buried beneath earth, concrete or in other ways inaccessible without the necessity of uncovering said lines or opening the fuel supply tank in the case of fuel supply, vent, or return lines.

Another object of my invention is to use portable equipment that may be taken from location to location which is capable of cleaning and freeing more than one line at a time without the necessity of attaching the device to and removing it from each line as it is to be cleaned or to work on another line of'a fuel oil system.

A further object of my invention is to use portable equipment and means for cleaning and freeing fuel oil supply, return and vent lines and plumbing waste lines in a relatively short period of time without necessity of taking the fuel oil supply system or waste lines out of service for a long period of time.

Referring to the drawings:

Fig. 1 is a side elevation of the pressure tank and oil and solvent heating receptacle with a portion of the side broken away, so as to show the steam heating coil therein. This view also shows three of the multiple heads in position, the air suction ejector attached for use, the air pressure line running into the upper multiple head, the till pipe, temperature gauges, pressure gauges and operating valves, etc.

Fig. 2 is a top plan view of the heating and pressure reservoir tank, showing three of the multiple heads in position, the pressure gauges, the air suction ejector in position, the automatic safety valve, and the operating valves of the multiple heads.

Fig. 3 is a plan view of a portion of the heating and pressure reservoir tank, showing thetandem arrangement of two of the multiple heads set up with the attachment for shooting chemical into a fuel oil supply tank on one of the multiple head outlets and also the suction and return lines of a fuel supply system attached thereto,.the reversible, variable speed pump and the second of the multiple heads showing parts of lines going to threeseparate sources of deposit for chemical, fuel oil and dissolved sludge withdrawn fromthe lines.

Fig. 4 is a side elevation View ofatypical steamer with a preheating device coupled to the steam outlet thereof, said preheating device being designed for insertion through the fill pipe into a fuel oil tank.

' Fig. 5 is a sectional view of the tank preheating device taken in the directionof the arrows along the-line'5 5 p of hose 36 is coupled to the oppositeend of the valve 35,

of Fig. 4, showing the generally spiral design of the end of said preheating device. The steam return pipe is not shown in this view.

Fig. 6 is a side elevational view of a portion ofa fuel supply tank with part of said tank broken away, so as to reveal the suction line and foot valve on the end thereof and the return line of a fuel supply tank. This view also shows a vent line with a portion thereof broken away.

Fig. 7 is a side elevational view in section of a pre' heating or reheating receptacle showing the water jacket, the oil compartment, the steam heated coil within the oil compartment and a drain outlet for the oil-compartment.

Fig. 8 is a schematic or diagrammatic view showing the connection and relation of the pressure reservoir tank and manifolds shown in Figs. 1 to 3 inclusive, the steamer shown in Fig. 4, the supply tank shown in Fig. 6, the.

heater shown in Fig. 7 and the vent, supply and return lines of a fuel oil heating system. The various gauges have been omitted from this figure for reasons of clarity.

Referring further to the drawings:

The reservoir pressure tank It] is equipped with a heat exchanging coil 11 whose inlet end 12 and outlet end 13 protrude from the end 14 of the said tank It}. A fill pipe 15 is located on the end 14 of the said tank It) and is equipped with a cap 16. Legs 17 support the reservoir pressure tank 10, and a drain plug 18 is located on the bottom side of said tank between the legs 17. A temperature gauge 19 is connected to the end 20 of said tank ill. An inlet pipe 21 is situated in the center of the upper side of said tank it) to which is coupled a short length of pipe 22; A conventional four-Way plumbing cross 23 is threaded to the top of the pipe 22. A pres sure gauge 24 is threaded to the top of the cross 23. Immediately adjacent to the cross 23 and on the left hand side thereof is coupled a screw type valve 25. A lever operated butterfly type valve 26 is then coupled to the valve 25 at-the end thereof opposite the cross 23'. A length of hose 27 is coupled to the butterfly type valve at the end thereof opposite the valve 25. Immediately adjacent to the cross 23, as shown in Fig. 1, is coupled a typical cross-head which is formed out of a conventionalplumbing cross such as the cross 23. Immediately adjacent to the cross-head and on the right hand side thereof opposite the cross 23 is coupled a screw type valve 28. Immediately adjacent to this valve and opposite the end coupled to the typical plumbing cross is coupled a butterfly type valve 29. The other end of the butterfly type'valve 29 iscoupled to a length of hose 3%) in which is situated a-constant pressure inlet valve 31. r The hose 30 is then attached to a source of compressed air. Onone side of the typical cross-head 32 is coupled a safety valve 33. On the opposite end of the crosshead 32 from the valve 33 is coupled a screw type valve 34 to which in turn is coupleda butterfly type valve 35. A length said length of hose 36 in turn being coupled to an air operated ejector 37. The end 37a of the air suctionejector deposits withdrawn oil, dissolved sludge, etc. in a Waste barrel not 'shown.-in the drawings; The leg 37b of the air suction ejector. is coupled to a butterfly valve 33 and a screw type valve 39 which is coupled to one outlet of atypical cross-head as. The opposite end of the four-Way cross-head 49 is coupled to another screw type valve 41 which in turn is coupled to a butterfly type I 42, the valve 42 being then coupled to a supply line, a

return line or a vent line, as the user may decide. In the center of the cross-head 4t) and on the top thereof is'locate'd a pressure gauge 4. 3 on the left hand side of the cross-head 4% as shown in Fig. 2 of the drawings,a

f-screw type valve 44 is, coupled. In turn a butterfly type va1ve*45iscoupled-tothe screw type valve 44. it stand.

. creating a ramming effect. 7 direction as above described, the chemical and oil soluard plumbing T 46 is then coupled to the butterfly type amen..-

valve 45. The outlet 47 on the leg of the T 46 at the operators option is coupled to a suction line, return line or vent line. On the right hand side of the cross-head 40fas shown in Fig. 2 of the drawings aserew type valve 48' is attached; to which in turn a butterfly type valve 49 is then attached, the valve 49 then beingiconpled to an outlet pipe 50 on the end 20 of the reservoir pressure and heating tank 10. The outlet 50'onthe end Ziland the outlet 51 on the end 14 of thesaid tank are located at the lowermost point of the diameter of said pressure and heating tank 10. A butterfly type valve 52 is coupled to the outlet pipe 51 on the end 14 of the reservoirpressure and heating tank 10." A screw type valve 53 is then coupled to the butterfly type valve 52. Atypical plumbing cross head 54 is coupled to the valve 53; a pressure gauge 55 is screwed into the middle of the cross-head 54. I On the opposite side of the cross-head 54 is coupled a screw type valve 56 to which is coupled a butterfiytype valve 57.: A conventional plumbing T 58 is then coupled to the valve 57; leg 59"of the T 58'may be attached to a suction line, a return line or a vent line at the operators option. To another side of the cross-head 54 is coupled a: screw type valve 60 which is coupled to a butterfly type valve 61 which is coupled to a vent, suction, or return line at the operators option. On the opposite side of the crosshead 54 is coupled a screw type valve 62 which in turn is coupled to a butterfly type valve 63. The valve 63 is then coupled to a waste line, a return line, a vent line or a suction line at the operators oplion. As shown in Fig. 3 of the drawings, a variable delivery reversible pump 64 is coupled to the T 58. To thereversible pump 64 on the side opposite the T 58 is coupled a standard cross-head 65. The remaining three outlets of the cross-head 65 are equipped with'a typical screw valve andbutterfly valve combination such as has been described in connection with cross-heads aforementionedin this specification. These outlets from the cross heads 65 enable the operator at his option to withdraw a hot oil and chemical andsludge from the line being cleaned and deposit it in a waste barrel, thepre-heating device, or the reservoir pressure and heating tank 111.

The combination of afcross head coupled to a lower outlet of the pressure-and heating tank 10, said crossheadbeing attached to a return line, a suct on line and a vent line or achemical spraying device 66 with a variable delivery reversiblepurnp between said cross-head and an outer cross-head whose threeoutlets run to variousplaces ofdeposit for the hot oil and chemical and sludge withdrawnjfrorn the lines is intended to be used on either end of'the reservoir, pressure and heating tank 10, Hence said tank 10 "may be equipped at either end ofboth ends simultaneously with a tandem cross-head set-up with'a reversible variable delivery pump between said cross-heads. By means of the said reversible pump 64 the operator is also enabled to withdraw deposited chemical and oil from one of the places in which it has been deposited and run it back through the same or a different line from which it was withdrawn. means of the reversible pump 64 and the pressure gauges 55 the operator is enabled through his pressure readings to tell when he hashita plug in a line and then to back the hot chemical and oils up bymeans of said pump 64 causing it to be deposited in one of the receptacles serviced by the cross-head 65. He can" again reverse the pump 64 forcing the hot oil and chemical against the plugged spot in said line from which it was withdrawn,

tion tends to have a wiping or scouring efiect onthe lines to be freed; If the operator so desires, in the use of the airejector 37, a positively maintained predeterw mined pressure orsuction can be attained in'the withdrawing phase by setting the constant pressure valve 31 at the pressure reading desired The air ejector 37 is i V 4 useful only for the purpose of backing up or withdrawing the oil and chemical solution from the line or lines being freed. Thus, if it has been determined the lines are old or too weak to stand with safety more than a given amount of suction or pressure, that pressure may be established by means of the valve 31 or by controlling the speed or delivery of the pump 64, so that the operation can be carried out without the operator having to worry about rupturing, collapsing, or damaging lines.

A tank spraying device 66 for shooting theinside of a fuel storage tank at various levels with a hot chemical cleaning and deslndging solution is provided at its end 67, which is generally circular in-shape, with a plurality of holes 68 in the circular portion thereof. The terrninology shooting the inside of a fuel storage tank as used in this specification is employed in the sense of disbursing hot oil, hot chemical and/or hot oil and chemical through and upon the interior of the fuel storage and supply tank. By coupling the tank operating device 66 to one of the three outlets on one of the inner crossheads, such as cross-head 54, by means of a hose 69, the inside of a fuel tank can be shot at various levels with the hot chemical deslndging solution at a predetermined pressure which is controlled by the setting on the constant pressure inlet valve 31. The tank spraying device 66 may be inserted through the fill pipe or the manhole opening of the fuel tank. 7

A portable steamer 70 of any standard make or design, such as is shown in Fig. 4, is connected by means of a hose 71 to the inlet end 12 ofthe heat exchanger coil 11 in the reservoir, pressure and heating tank 10. The steamer 70 provides and generates the necessary heat which is transferred through the heat exchanger coil 11 to the hot chemical and oil solution in the reservoir pressure and heating tank 10. When the desired temperature, as shown by the thermometer;19 on the end 20 oi the reservoir pressure and heating tank 10, has been obtained, the line gauge 31 is set at a predetermined pressure, and compressed air is introduced through the hose 30, the valve 29, the -valve"28, the cross-head 32, the vertical cross 23, the pipe 22 and the inlet opening 21 into the reservoir pressure and heating tank 10. The operator by opening and closing the proper valves is ready to start freeing one of the lines connected to an outlet of an inner cross-head. As soon as the first line has been freed, which will be indicated bythe change in pressure registered on the pressure gauges 43 or 55, the operator is then immediately able to work on' another line by V merely opening and closing the proper valves on the oross head to make the desired outlet accessible to the hot chemical and oil solutiorr'in the reservoir, pressure and heating tank 10. Thus after the equipment has been set up and attached to;the lines, which are in need of Thus by cleaning and freeing, the operator can carry on the whole operation by merely changing the openings on valves and without the necessity of any further couplings or uncouplings until the job has been completed.

A tank preheater 72, as shown in'Fig; 4, is coupled by lengths of hose to the steamer and then inserted through the manhole of the fuel oil supply tank. The end 73 of the tank preheater 72is generally spiral indesign for the purpose of obtaining a greater heating area within the fuel oil supply tank. The spiral 73' emerges into the return pipe 74 of the tank'preheater 72. ,The return pipe 74is coupled by means of a hose 75 to the return connection of the steamer 7 0.7 The whole tank preheater '72 is constructed preferably of copper tubing;

By alternating the pumping A'portion of a typical fuel oil supply tank 76 with a part thereof broken away is shown in Fig. 6. 1A suction line 77 with a foot valve 78 at the bottom thereof is shown in place in the tank 76;. Also, a return line 79 and vent line 80 are shown in place on the tank 76,

Oftentimes the source of trouble in a blocked fuel oil supply system resides in the foot valve 78 which becomes of carbon. attaching the end of the suctionline 77,

line and rammed back and forth, as described above, until the line has been completely freed and scoured out, including the foot valve 78. This is accomplished without the necessity of entering, opening or excavating the fuel oil supply tank or of excavating or uncovering the suction line, return line or vent line of the heating system, as the case may be.

A typical vent line 80 has three 90

elbows

81, 82 and 83 inserted in such a manner as to allow for the'settling of the fuel oil tank 76 into any direction without breaking the vent line 80. Oftentimes when a tank settles the resulting angles created by the shifting of the vent line through the 90

elbows

81, 82 and 83 creates a low section in the vent line which becomes blocked by fuel oil when the tank is filled to the capacity it is supposed to hold. This results eventually in a sludge formation and a blocking of the vent line 80 so that the tank 76 is unable to breathe properly, resulting in the burner unit 'not functioning as it should. The vent line 80 may also be coupled to one of the outlets of one of the inner crossheads such as cross-head 40 and freed in the same manner as a suction line or return line without the necessity of excavating said vent line 80.

The same process using the reservoir pressure tank 10, the air pressure line 30, constant pressure inlet valve 31, inlet pipe 21, typical inner cross-heads 40 or 53, variable delivery pump 64, the air suction ejector 37, etc., may be employed to free plumbing waste lines which have become clogged from accumulation of coagulated grease and sludge without the necessity of expensive repairs, replacements or disassembly.

An oil and chemical preheater or reheater can be used in connection with my device through the medium of one of the outlets of one of the outer cross-heads 65. Said preheater or reheater has an outer jacket 84 and an inner jacket 85, the inner jacket 85 forming a container 86 for receiving oil and chemical solution. is concentrically located within the outer jacket 84, forming a water containing space 87 around all sides and the bottom of said inner jacket 85. A heat exchanger coil 88 is positioned within said space 86 of said inner jacket 85. Said heat exchanger coil 88 is provided with an inlet connection 89 and an outlet connection 9%), said ends 89 and 90 being fastened to a source of heat such as the steamer 70. A drain plug 91 is positioned at the lower Said inner jacket 85 portion of the inner jacket 85 so that the oil and chemical solution may be drained out of the space 86 without disturbing the water in the space 87.

By means of a hose from one of the outlets of a typical 7 outer cross-head 65, the preheated oil and chemical solution within the space 86 may be pumped into the particular line being cleaned by means of the reversible variable delivery pump 64, or the oiltand chemical solution may be withdrawn fromthe line being freed and redeposited in the space 86 of the perheater or reheater receptacle for reheating said oil and chemical before ramming it back into the line to be freed. This operation is carried out entirely through the medium of the reversible variable delivery pump 64. H

The preheater or reheater receptacle is provided with the water space 87, in addition to the heat exchanger coil 88, so that the preheater or reheater receptacle may be set directly on an open flame, if desired, to speed up the process of preheating or reheating the oil and chemical solution within the space 86. The preheater or reheater also serves as an auxiliary supply source for oil and chemical solution which is available in the event the lines being cleaned are so long that more solution is required than can be held in the reservoir pressure and heating tank 10, or in the event that it is more convenient to draw oil and chemical from "this source 'in connection with theing'of my device. This arrangement has been embodied in my device so that the operator will have a valve available for rapidly shutting off or opening an outlet or inlet by means of the butterfly type valve, and Will also have available a slower operating but more positively locking screw type valve. It is understood that the arrangement as shown in the drawings is the preferable embodiment of this invention, but that I am not limiting myself to this particular embodiment. It is further understood that in the use and operation of my equipment I first place the oil selected for the particular cleaning operation or the said oil in combination with a desludging chemical in the reservoir pressure and heating tank 10 and, if a greater quantity of oil and/or chemical and oil solution is required, such additional supply is placed in the space 86 of the receptacle shown in Fig. 7 of the drawings, which receptacle is a combination preheater, reheater and auxiliary heater and auxiliary supply reservoir for oil or oil and chemical solution. I

It is also understood that in connection with the operation of the reversible variable delivery pump 64 hot oil, chemicals and dissolved sludge may be returned to the reservoir "pressure and heating tank 10, the auxiliary heater and supply reservoir receptacle combination device shown in Fig. 7 of the drawings, or a waste barrel, selectively, or that said oil, chemical and/or dissolved sludge may be deposited in a waste barrel by means of the

air ejector

37, 37a, 37b. f

Having thus described my invention what I claim is: l. A process for cleaning the interior ofa plugged, inaccessible line having an accessible end consisting of drawing hot oil from an exterior source, forcing said hot oil into the accessible end of said line and against the plug therein at a controlled and predetermined pressure until said plug has been dissolved, withdrawing said hot oil and dissolved plug through said accessible end at a controlled and predetermined suction and redepositing said hot oil and dissolved plug in said exterior source.

2. A process for cleaning the interior of a plugged, inaccessible line consistingof withdrawing hot oil in combination with a desludging chemical from an exterior source, forcing said hot oil and desludging chemical combination into anaccessible end of said line and against the plug therein until said'plug is dissolved, withdrawing said hot oil and chemical combination and said dissolved plug I withdrawing the said hot oilunder a controlled and predetermined suction from within said line and away from said obstruction through said accessible end until said obstruction is dissolved and redepositing said hot oil and dissolved plug in said exterior source.

4. A process for cleaning the interior of plugged transmission ,pipe lines in a fuel oil supply system, said lines being inaccessible, consisting of withdrawing hot oil in combination with a desludging element from an exterior source, forcing said hot oil and desludging chemical combination into the interior of said lines and against the obstruction therein through accessible ends of said lines, alternately withdrawing the hot oil and desludging chemical combination until the obstruction'in the interior of cals combination under a controlled and predetermined pressure-through the accessible end of said line, 'alter- :uately withdrawing said hot oil and desludging chemicals gombinationfrom said pipe through its accessible end at a controlled and f predetermined, suction, alternately re; introducing said. hotloilinto the; interior or said .line

' through its accessible, end and withdrawing the'same and forcingsaid heated oil and desludging chemical solution combination into the interior of said transmission lines through the points of access to each of said lines and against the plug therein,:controlling'and predetermining the pressure applied to the said heated oil and de- "slud ging chemical solution, withdrawing the heated oil and desludgi ng chemical solution and dissolved sludge through the point of access of each of said transmission lines beiug cleaned, controlling and predetermining the suction influence applied to said heated oil and desludging fchemical combination and dissolved sludge while withdrawing it through the point of access of each ofsaid lines, alternately forcing'the heatedoil'and desludging chemical solution into and withdrawing it from each of said transmission lines being cleaned through the point of access of each, controlling and predetermining the pressure and suction applied to said heated oil and desludging chemical combination during the alternate forcing and withdrawing of said heated oil and desludging chemical combination, redepositing the withdrawn oil and desludg ing chemical solution and dissolved sludge in said exterior containers, inserting a heater'into the fuel supply tank through thepoint of access thereof and heating the fuel in'said fuel supply tank, withdrawing heated oil and desludging chemical combination from another exterior contaiuer, and through the point ofaccess of said fuel supply tank, dispersing said heated oil and desludging chemical solution under controlled pressure at various levels throughout the fuel in said tank, thereby dissolving sludge accumulations from the interior surfaces of said tank.

P 6., Aprocess for cleaning sludge from the interior of plugged, inaccessibletransmission lines and vent lines for oil heating equipment and from other inaccessible lines in which sludgeaccumulates, each of said lines having one accessible end, consisting of withdrawing hot oil from oneoflseveral exterior sources, forcing said hot oil into the accessible end of each of said lines under a controlled and predetermined pressure, alternately withdrawing said hot, oil through the accessible end of each of said lines ata controlled and predetermined. suction, repeating betweenforcing the hot 'oil into theaccessible end of each "of said lines and withdrawing it through the accessible end .of' each of said lines under controlled pressure andsuction until the sludge accumulation therein is dissolvedand each of said lines is clean, relieving the prescessible end, consisting oi withdrawing hot oil in combination with desludging chemicals from one of several exterior sources, forcing said hotoil and desludging chemithrough said end at predetermined and controlled pressures andsuctions until said line is clean and then withdrawingsa'id' hotoil, and desludging chemicals combination from said line through its accessible end and redepositing said oil and desludging chemicals combination and dissolved sludge into any of said several exterior sources.

:8. A process for cleaning the interior ofplugged, inaccessible.fuel'transmission lines and of fuel supply tanks connected therewith, each of said lines and said tank having only one point of access, consisting of heating a desludging chemical solution in exterior containers, withdrawing said heated desludging chemical solution from said exterior containers and forcing said heated desludging chemical solution into the interior of said transmission lines through the point of access to each of said lines and against the plug therein, controlling and predetermining the pressure applied to the said heated desludging chemical solution, withdrawing the heated dcsludging chemical solution and dissolved sludge through the point of access of eachof said transmission lines being cleaned, controllingand predetermining the suction influence applied to said deslhdging chemical solution and dissolved sludge while Withdrawing it through the point of access of each of said lines, alternately forcing the heated desludging chemical solutioninto and withdrawing it from each of said'transrnission lines being cleaned through the point of access of each, controlling and predetermining' the pressure and suction applied to said heated desludging chemical solution during the alternate forcing and withdrawing of said .desludgirig chemical solution, redepositing the Withdrawn desludging, chemical solution and dissolved sludge'in said exterior containers, inserting a heater into .the-fuelsupply tank through the point of access thereof and heating the fuel in said fuel supply tank, withdrawing heated desludging chemical solution from another exterior container, and through the'point of access of said fuel supply tank'dispersing' said heated desludging chemical solution under controlled pressure at various levels throughout thefuel in said tank, thereby dissolving sludge accumulations fromthe interior surfaces of said tank.

References Cited in the file of this patent UNITED STATES PATENTS "1,198,045 Miller Sept. 12, 1916 1,757,035 Beckman- May 6, 1930 2,078,740 Stahl Apr. 27, 1937 2,092,321 McFadden Sept. 7, 1937 2,222,516 Powell Nov. 19, 1940 2,324,804 Van Gelderen' July 20, 1943 2,338,586 Keller Jan. 4, 1944 2,399,205 Campbell Apr. 30, 1946 2,399,267 Szatyn Apr. 30, 1946 32,454,585, Alderman Nov. .23, 1948 2,494,380 Ellig Jan. 10, 1950 2,598,963 Armstrong June '3,

2,685,347 7 Busby Aug. 3,

Claims

1. A PROCESS FOR CLEANING THE INTERIOR OF A PLUGGED INACCESSIBLE LINE HAVING AN ACCESSIBLE END CONSISTING OF DRAWING HOT OIL FROM AN EXTERIOR SOURCE, FORCING SAID HOT OIL INTO THE ACCESSIBLE END OF SAID LINE AND AGAINST THE PLUG THEREIN AT A CONTROLLED AND PREDETERMINED PRESSURE UNTIL SAID PLUG HAS BEEN DISSOLVED, WITHDRAWING SAID HOT OIL AND DISSOLVED PLUG THROUGH SAID ACCESSIBLE END AT A CONTROLLED AND PREDETERMINED SUCTION AND REDEPOSITING SAID HOT OIL AND DISSOLVED PLUG IN SAID EXTERIOR SOURCE.