Apparatus and method for opening drains

The present invention discloses an apparatus for opening drains and the like, and includes a suitable vacuum/pressure source such as a household or industrial wet/dry vacuum cleaner with a control mechanism fitted to the vacuum cleaner or an intermediate receptacle for sequentially applying vacuum/pressure pulses to a clogged drain for loosening and purging the blockage occurring in the drain.

The present invention is directed to an apparatus and method for opening 
slow and clogged drains in commercial, industrial and household 
applications and for purging any type of radiator cooled engines such as 
cars, trucks, etc., and cooling systems for marine inboard and outboard 
motors. 
It is a common problem that drains of various kinds such as household 
plumbing drains including bathtubs, showers, and so forth, periodically 
become clogged and need to be opened to restore normal usage. Typical 
methods for clearing drains call for the use of chemicals including 
caustics and acids which are highly detrimental to plumbing systems and 
plumbing fixtures. Chemical treatments tend to destroy metal fittings 
while caustics attack ABS pipes, and acids attack porcelain. These 
chemicals are dangerous to handle and are pollutants. In other techniques, 
high pressure drain opening systems tend to rupture plumbing joints and 
snakes tend to damage the finish of plumbing fittings and fixtures. 
Accordingly, there is need for a safe, nondestructive, nonpolluting way of 
dealing with clogged plumbing drains. 
Motor vehicle radiators over a period of time accumulate rust scale and 
other deposits which impede cooling efficiency and require periodic 
flushing to remove accumulated materials and to restore the radiator to 
full heat exchange efficiency. Typically, high pressure devices or acids 
are used for cleaning automobile radiators and are detrimental to the 
structural integrity of the radiator. 
Marine inboard and outboard motors ordinarily have cooling systems using 
ambient water and tend to become coated with foreign materials carried 
along in the cooling water. It is desirable periodically to flush the 
cooling systems to remove such materials which substantially interfere 
with heat transfer of the cooling system and also when winterizing an 
engine. 
When winterizing swimming pools, the filter system is secured and it is 
desirable to purge the filter lines of water and debris which remain in 
the lines. 
There is a need for an apparatus and method which can quickly and 
effectively deal with clogged drains and flushing radiator and cooling 
systems and aid in cleaning or winterizing swimming pools. 
SUMMARY OF THE INVENTION 
The present invention provides a method and apparatus for conveniently and 
effectively opening drains in plumbing systems which is applicable to 
other opening/flushing operations such as cleaning motor vehicle radiators 
and marine engine cooling systems. According to the invention, a series of 
pressure pulses both positive and negative are applied in rapid succession 
effectively to move and clear away debris blocking drains or to aid in 
purging and flushing cooling systems. 
In one form of the invention the drain opener includes an ordinary 
household wet/dry vacuum cleaner fitted with a pressure reversing header 
for quickly applying a repetition of negative and positive pressure pulses 
to the plugged drain. The header includes a manually operable valve member 
which when manipulated causes the wet/dry vacuum cleaner to apply 
alternate pressure and vacuum pulses to the drain in rapid succession 
effectively to clear the drain. In a modification of the invention, 
pressurized water and/or detergent cleaners can aid in drain opening. 
In another form of the invention, the drain opener is suitable for use with 
household canister-type dry vacuum or wet/dry vacuum cleaners having a 
vacuum port and an exhaust port. The drain opener includes a wet canister 
fitted with a pressure reversing header connected to a dry vacuum cleaner 
by suitable hose connections. In this form of the invention the household 
vacuum cleaner whether dry or wet/dry are used for supplying pressure and 
vacuum pulses while the wet canister serves as receptacle for effluent 
form clogged drains. 
OBJECTS OF THE INVENTION 
It is an object of the invention to provide a drain opener for rapidly 
cleaning clogged drains, motor vehicle radiators, marine engine cooling 
systems and the like, and purging filter system lines when winterizing or 
cleaning swimming pools. 
Another object of the invention is to provide a fitting for a typical 
wet/dry vacuum cleaner which effectively applies alternating pulses to 
open drains. 
A further object of the invention is to provide differential pressure 
pulses of a low magnitude which will not overpressure and damage household 
plumbing fittings or engine cooling systems. 
Another object of the invention is to provide a drain opener suitable for 
use with canister-type dry and wet/dry vacuum cleaners in which the 
effluent form a slow or clogged drain is collected in a separate 
receptacle. 
A further object of the invention is to provide a drain opener which is 
safe to use, does not damage plumbing fittings and fixtures, and does not 
result in chemical pollution of plumbing systems, septic systems, 
underground sewers, and so forth. 
Another object of the invention is to provide a valve to alert the operator 
when effluent fills the receptacle. 
A further object of the invention is to provide fittings for applying the 
method and apparatus to specific drains. 
Other and further objects of the invention will become apparent on an 
understanding of the following detailed description or will become 
apparent to one skilled in the art upon employment of the invention in 
practice.

Referring to the drawing, a preferred embodiment of the apparatus 10 for 
opening drains includes a suitable pressure/vacuum source, as for example, 
a wet/dry vacuum cleaner 12, a pressure/vacuum control manifold 14, and an 
operating hose 16 for opening a drain 18. 
The vacuum cleaner includes an upright receptacle 20 having a motor driven 
fan 22 for drawing vacuum through an inlet port 24 to the interior 26 of 
the recepticle or canister 20 and for exhausting air from the canister 
through an outlet port 28. In this description these ports are referred to 
as vacuum port 24 and pressure port 28. 
The wet and dry vacuum cleaner operates in the usual fashion to draw debris 
into the canister through vacuum port 24 while exhausting or evacuating 
the interior of the canister through pressure port 28. This basic manner 
of operation applies with respect to the present invention. The 
pressure/vacuum control manifold regulates the drain opening apparatus so 
as selectively to apply pressure or vacuum through operating hose 16 to 
drain 18. 
The control manifold 14 includes an upright block shaped housing 30 formed 
of any suitable material such as rigid plastic or cast aluminum. The 
manifold includes interior vacuum 32 and pressure 34 ducts and exterior 
conical vacuum 36 and pressure 38 sleeves for connection to the vacuum 24 
and pressure 28 ports of the vacuum cleaner. The vacuum and pressure ducts 
merge into an upwardly extending two-way pressure/vacuum duct 40 with an 
access port 42 located in the top surface 44 of the manifold. The front 
wall 46 has openings 48, 50 communicating with the interior vacuum and 
pressure ducts respectively for the purpose of drawing air into or 
exhausting air from the canister during operation as more fully developed 
below. 
The control manifold further includes a control mechanism 52 for directing 
pressure/vacuum flow within the operating hose 16. The control mechanism 
includes a pivot shaft 54 extending horizontally through the manifold and 
lying along the top of a partition 56 separating the interior vacuum 32 
and pressure ducts 34. The shaft is pivotally mounted between the front 46 
and rear 50 walls of the manifold and includes a projection 60 extending a 
short distance from the front wall. 
A blade-shaped valve or damper 62 is supported by and projects radially 
from the surface of pivot shaft 54 for directing flow through two-way duct 
40 and operating hose 16 by blocking either interior vacuum duct 32 or 
pressure duct 34. The contour of blade valve conforms to the interior wall 
surface of vacuum duct and pressure duct at their places of confluence 
with two-way duct in an air tight fit to avoid pressure loss during 
operation. The control mechanism further includes a movable cover 64 for 
selectively closing openings 48, 50 in front wall 46. The cover is 
connected to pivot shaft 54 by means of extension rod 66 for pivoting 
movement between the openings. A suitable knob 68 is fitted to the cover 
for ease of manipulating the cover. It is to be observed that blade valve 
62 and extension rod 66 are coplanar so that when the blade valve covers 
the pressure duct 34, for example, the pressure opening 50 will be 
uncovered and vice-versa for vacuum duct 32 and vacuum opening 48. 
In operation, the control mechanism is set in one position as for example, 
the solid line position of FIGS. 2 and 3 in which case exhaust air is 
expelled from the vacuum cleaner through the pressure duct 34 and pressure 
opening 50 while the external cover 64 closes vacuum opening 48 and opens 
vacuum duct 32 drawing air into the vacuum cleaner through hose 16. The 
position of valve 62 assures draw of partial vacuum through operational 
hose 16 and application of vacuum to the blocked drain. By reversing the 
position of the handle and control mechanism (to the dash line position of 
FIG. 3), pressure is now applied to the operating hose and drain. As shown 
in the dash line portion of FIG. 3, air is pushed into the operating hose 
through pressure duct 34 and into the drain while open vacuum port 48 
provides for inflow of ambient air into the system. 
By periodic manipulation of the control mechanism differential pressure 
pulsations are applied for effectively clearing the drain. 
In like manner, the mechanism can be applied to other fittings such as 
automotive radiators, marine engines, and so on, for cleaning the fluid 
passages of such devices. 
The invention is useful for cleaning or winterizing swimming pools 
particularly in purging water and any debris lodged in the filter 
recirculating and distribution lines. 
If desired, auxiliary drain clearing aids such as detergent or pressurized 
water can be introduced through hose fitting 17 by means of an applicator 
19 as shown in FIG. 1 and also in FIG. 4. 
FIGS. 4 and 5 present a modification to the present invention in which 
water feed accompanies the positive pressure pulses of the system as an 
aid in opening drains and the like. Here a hand-held nozzle 70 is attached 
to hose fitting 17 and has a suitable fitting 72 for receiving a water 
supply hose. The nozzle includes a suitable valve 74 and is trigger 
actuated 76 for water supply. Additionally, the trigger forms part of an 
electric circuit 78 which also includes a control manifold solenoid 80 
shown in FIG. 5. As the trigger is actuated water is applied to the drain 
and the solenoid-actuated movable cover 66 moved to the positive pressure 
mode. By releasing the trigger the water-feed is interrupted and a vacuum 
pulse applied to the drain. If desired, the nozzle may be used to feed 
detergents, degreasers, etc., to a drain. 
A further modification of the invention is illustrated in FIGS. 6 and 7. 
The modified control manifold 90 includes an upright block-shaped housing 
92 with an interior chamber 94 and a movable blade valve or damper 96 for 
directing pressure and vacuum pulses to a closed drain. The interior 
chamber includes a pressure chamber 98 through which pressurized air is 
applied to the drain or exhausted to atmosphere and a vacuum chamber 100 
through which air is drawn from the drain or from atmosphere. The control 
manifold is generally rectangular in cross-section and includes rear 102, 
front 104 and side walls 106 of integral construction preferably of 
injection molded polypropylene. The side walls taper upwardly and inwardly 
at 102a from approximately two-thirds their vertical dimension terminating 
at a inlet/outlet sleeve 108. The upper portions of the front and rear 
walls are joined to and follow the contour of the tapered side wall 
portions 102a. The inner surface 110 of both tapered side walls just below 
inlet/outlet sleeve is beveled to form a sealing surface for engagement 
with the upper sealing surfaces 112 on both sides of the blade valve. An 
operating hose 113 fitted to the inlet/outlet sleeve communicates vacuum 
and pressure pulses to the drain. 
The control manifold also includes an interior partition 114 comprising 
spaced partition walls 116 vertically oriented and extending between and 
attached to the front and rear walls. The interior partition is molded 
integral with the control manifold. The upper edges 118 of each partition 
wall are beveled to form a sealing surface for engaging the lower sealing 
surfaces 120 of the blade valve. Additionally, a stop shoulder 121 is 
located at the upper edge of each partition wall for limiting movement of 
the blade valve. The partition walls cooperate with the front wall and 
direct air into and out of a single inlet/outlet port 122 in the front 
wall. 
The lower ends of the pressure and vacuum chambers have outlet 123 and 
inlet 125 ports, respectively, for connection to the corresponding ports 
of a vacuum cleaner substantially as shown in FIG. 1. 
The generally rectangular blade valve shown in FIG. 7 comprises an 
imperforate valve plate 124 divided into major 124a and minor 124b parts 
along a pivot axis A--A defined by a hollow pivot hub 126. The pivot hub 
is generally cylindrical and is formed integral with the valve plate of 
suitable material such as polypropylene. The pivot hub receives a pivot 
shaft 128 which is assembled into the manifold at pivot openings 130, 132 
located in front 104 and rear walls 102. A handle member 134 is fitted to 
the front end of the pivot shaft for manipulating the blade between vacuum 
and pressure positions. 
As shown in FIG. 6, the control manifold has its blade valve closing the 
pressure chamber so that in operation the vacuum cleaner applies a vacuum 
pulse to the closed drain through inlet sleeve 108 and operating hose 113. 
Pressurized air from the vacuum cleaner enters the pressure chamber and is 
exhausted through outlet port 122. By reversing the valve position to the 
dash line position of FIG. 6, a pressure pulse is applied to the closed 
drain through outlet sleeve 108 and ambient air is drawn through the inlet 
port 122 into the vacuum chamber providing the source of pressurized air 
to the closed drain through operating hose 113. 
The blade valve includes a spring member 136 (FIG. 7) fitted between the 
pivot shaft and front wall for resisting the tendency of the blade valve 
to shift (FIG. 6) under the influence of a pressure differential acting on 
the blade valve in the vacuum mode (solid line position of FIG. 6). 
Alternatively, a ball/detente arrangement between front wall 104 and the 
operating handle 134 may be used to provide positive positioning and 
holding of the blade valve in both pressure and vacuum positions. 
FIGS. 8 and 9 illustrate a modification of the pressure/vacuum manifold of 
FIG. 6. This form of the manifold 90 includes housing 92, interior chamber 
94 and damper 96 for directing pressure and vacuum pulses to a closed 
drain. The damper 96 is manipulated between vacuum (full line) and 
pressure dash line) positions by means of operating handle 138. A pivot 
shaft 140 is mounted between front 142 and rear 144 walls and receives 
damper 96 in the manner of FIGS. 6 and 7. First and second levers 146, 148 
are fitted to the ends of the pivot shaft extending along the front and 
rear walls and are joined at one end by a laterally extending gripping 
handle 150. The other ends of the levers extend away from the pivot shaft 
to provide balance to the operating handle. The outer surfaces of the 
front and rear walls are provided with abutments or stop members 152 which 
limit the movement of the operating handle without stressing the blade 
valve. The stop members 152 are conveniently molded integral to the front 
and rear walls. The operating handle is weighted for the purpose of 
counteracting the tendency of the blade valve 96 to move counterclockwise 
(FIG. 8) by reason of the pressure differential on the vacuum 96a face and 
pressure face 96b. The same pressure differential is sufficient to hold 
the operating handle in the pressure mode (dash lines FIG. 8). The handle 
itself provides a convenient and durable structure for rapidly switching 
the unit from pressure to vacuum modes. The other structural elements of 
FIGS. 8 and 9 have numerals corresponding to the same structural elements 
of FIG. 6. 
FIG. 10 is a further modification of the invention illustrating a drain 
opener including a pressure/vacuum control manifold and receptacle for 
connection to a canister-type dry or wet/dry vacuum cleaner. 
The drain opener includes a dedicated intermediate canister or receptacle 
156 for receiving effluent from a plumbing drain 18, pressure/vacuum 
control manifold 90, and a canister-type dry or wet/dry vacuum cleaner 
158. The arrangement provides for communication of pressure/vacuum pulses 
to plumbing drain 18 from pressure/vacuum source such as the canister-type 
vacuum cleaner 158 without requiring to the source vacuum cleaner to 
receive effluent from the plumbing drain. The effluent is received and 
retained by the intermediate canister 156. This modification includes a 
pressure/vacuum control manifold 90 as described above for FIGS. 8 and 9 
as reflected by corresponding reference numerals of FIG. 10. As described 
above, the pressure/vacuum manifold 90 directs pressure or vacuum pulses 
through hose 113 to plugged plumbing drain 18. 
The intermediate canister includes a bucket 160 of suitable capacity, e.g. 
five gallons, and tightly fitting top cover 162 held in place by several 
snap fittings 164. The top cover includes fittings defining a vacuum line 
166 and a pressure line 168. 
The vacuum line 166 includes a circular port 166a in the top surface of the 
cover and an upwardly directed elbow fitting 166b for connection to the 
vacuum port 158 of vacuum cleaner through a suitable hose 168. Both 
circular port 166a vacuum elbow 166b are open to the interior 170 of the 
bucket. 
The pressure line 168 also includes a circular port 168a and an upwardly 
directed elbow 168b similar to the vacuum line fittings, however, the 
pressure line further includes a conduit connection 168c directly between 
pressure elbow and pressure port so that pressure pulses are sent from 
pressure source 158p through hose 172, pressure line 168, manifold 90 to 
plumbing drain via hose 113. In other words, the interior of the bucket is 
not subjected to pressure pulses. 
In operating the embodiment of FIG. 10, the operating handle 150 is set in 
vacuum mode (solid lines) and a vacuum pulse drawn on clogged drain by 
vacuum source 158v. The bucket interior 170 is subject to vacuum 
conditions developed by the vacuum source. Effluent drawn from the drain 
in this operating mode is trapped in the bucket. By merely reversing the 
operating handle to pressure mode (dash lines) a pressure pulse is 
directed from pressure source through pressure line, manifold, hose 113, 
to drain. When the drain is clear, effluent in canister can be disposed of 
by removing the top cover. 
If desired a liner 171 (FIG. 10) can be used for collection and disposal of 
effluent received by the container 160 (FIG. 10) or 20 (FIG. 1). 
Preferably the liner is of heavy guage sheet material or of rigid material 
to maintain its shape in the vacuum mode. 
FIGS. 11a and 11b illustrate a further modification of the invention. In 
this form of the invention the pressure/vacuum manifold 180 is arranged in 
horizontal orientation within an outer housing 182 of the drain opening 
device. A motor driven fan 184 within the housing provides pressure P and 
vacuum V sources with suitable connections 186, 188 to the manifold. The 
housing includes a base plate 190 and external cover 192 and is mounted on 
a receptacle 194 for receiving effluent from a closed drain and with a 
liner 171. A control damper 196 is mounted within the manifold on a pivot 
shaft 198 dividing interior chamber 200 into pressure 202 and vacuum 204 
chambers. Preferably, the damper and its pivot shaft are integral and 
molded of suitable plastic. A U shaped handle 206 is fitted to opposite 
ends of the pivot shaft for manipulating the damper. A knob 208 attached 
to the handle through slot 210 provides for gripping and manipulating the 
damper. In operation, the damper normally assumes the position shown in 
FIG. 11a, i.e., the pressure mode where the incoming pressurized air opens 
the damper to direct pressure through the inlet/outlet port 212 to drain. 
As in the case with the embodiment of FIGS. 1-10, the damper is shifted 
from vacuum to pressure mode to provide sequential vacuum and pressure 
pulses to a drain. As shown in FIG. 11b, the operating handle may be 
restrained in the vacuum mode by a ring 214 fixed to the housing adjacent 
the slot 210. The restraining ring 214 is pivotally mounted to a base 
member 216 fixed to the housing. The ring slips over the knob and holds 
the damper in the vacuum position against the force of pressurized air 
which is directed through exhaust port 218 to atmosphere. In this 
position, the drain opening device can now be used as for wet vacuum 
operations with waste collected in the lined receptacle 194 through the 
two way duct 220 and vacuum chamber 200. 
FIG. 11b further illustrates a force cup 222 particularly adapted for use 
with the present invention. The force cup includes a hemispheric upper 
portion 224 which is truncated to define an opening 226 for communicating 
with two-way duct 220. The edge of the force cup around opening 226 is 
flanged 228 for ease in connection with the two way duct. The opposite end 
230 of the hemispheric portion includes an integral hollow neck wall 
portion 232 of gradually reduced diameter as the neck wall converges to an 
open end 234. The force cup is molded integral of rubber or a suitable 
rubber substitute with sufficient resiliency to conform to a variety drain 
contours and wall sufficient strength to withstand vacuum within as the 
drain opening device is used in vacuum mode particularly the wet vacuum 
mode of FIG. 11b. 
In operating the drain opening apparatus with a receptacle liner, it is 
desirable for the liner to maintain its shape within the receptacle and 
not to interfere with the vacuum draw from the receptacle. As shown in 
FIG. 11a, the liner is provided with a pleated sidewall 171a for 
maintaining side wall rigidity for resisting side wall collapse during 
operation. Additionally, liner bottom wall 171b is fitted with double 
coated tape strips 171c for securing the liner to the receptacle bottom 
wall 194a. As a further measure in maintaining liner shape, manifold 
connection 188 extends well into the interior of receptacle 194 directing 
air flow therefrom toward the liner bottom wall 171b. 
Manifold connection 188 preferably extends at least half the depth of 
receptacle and its length may be selected by user or manufacturer for the 
purpose of determining the volume of effluent received by the receptacle. 
When the effluent level rises to cover the lower open end 189 of 
connection 188 the air flow characteristics of the apparatus are changed 
and a change of motor pitch will alert the operator that the volume limits 
of the receptacle have been reached and the receptacle is to be emptied. 
This safety arrangement assures that no effluent will flow into the fan 
184 through vacuum intake connection 186. 
A modified safety arrangement 240 is shown in FIG. 12 for positively 
closing a manifold connection 186 for assuring that no effluent will flow 
into fan 184 (FIG. 11a). The safety arrangement includes a float valve 242 
which closes manifold connection preferably the pressure connection 186 
when effluent in the receptacle rises from below level A--A to level B--B. 
As shown, the receptacle cover or base plate 190 is open at 244 to 
accommodate manifold connection 186 which extends a short distance into 
the receptacle interior 170. 
The safety valve assembly 240 comprises an open cagelike structure 
including upper 248 and lower 250 rings interconnected by a plurality of 
tubular posts 252. There are preferably four posts equally spaced about 
the perimeters of the upper and lower rings, with just two posts being 
illustrated in FIG. 12. The rings are fabricated of suitable inert 
material such as rigid plastic. The upper ring has a central opening 254 
by which it is fitted onto the depending portion 256 of the manifold 186 
connection and retained by a suitable fastener 258. The upper end 260 of 
each post is secured by suitable means not shown to the upper ring. The 
lower ring is fitted to the lower end 262 of each post and held there by 
suitable fasteners 264. The lower ring has a central opening 266 to 
accommodate the body of a float 268 forming part of the float valve 
assembly. The float valve 242 is also in the form of a ring or disc 270 
with a central opening 272 slightly greater in size (diameter) than the 
lower end 256 of the manifold connection 186. The outer perimeter of the 
float ring includes a plurality of peripherially located openings 274 
which permit sliding or floating movement of the valve upward and downward 
of the supporting and guiding posts 252. The floating disc 270 is provided 
at its underside with a float 268 of suitable buoyant material and of 
sufficient volume for floating upwardly on the effluent surface as it 
rises from below level A--A to level B--B shown in FIG. 12. When the float 
valve 242 reaches the upper limit of its excursionary range the upper 
surface 278 of the buoyant block exposed through ring opening 272 now 
closes the lower end 256 of the manifold connection barring entry of 
effluent. As this occurs, the normal sound of the operating motor 184 
(FIG. 11a) will change pitch alerting the operator that the receptacle is 
filled and must be emptied. 
It is also desirable to provide a suitable mesh screen 280 encircling the 
float valve assembly to assure that the buoyancy of the float valve is not 
altered by accummulation thereon of debris floating in the effluent. 
The present invention further provides a set of fittings 290 for applying 
the drain opening apparatus to drains including sink drains (FIG. 13), 
shower stall drains (FIG. 14), and to automotive or marine radiators (FIG. 
15). In each case the fittings include an adapter in the form of a 
truncated cone 292 having a central bore 294 for communicating vacuum and 
pressure pulses (indicated by arrows v and p) to a drain. The upper 
surface 296 of each adapter is greater in diameter than the lower surface 
298 with an intervening outer conical surface 300 and is thereby enabled 
to seal drain openings of various sizes typically 1 to 3 inches. The upper 
surface of each adapter is recessed at 302 to accommodate the end of 
inlet/outlet duct 220. 
The fitting 290 (FIG. 14) for shower drains further includes downwardly 
extending extension tubes 304 for applying pressure and vacuum pulses 
directly to material (M) blocking the drain which normally occupies the 
gooseneck section of the drain. The extension tubes are supported from the 
adapter shoulder or recess 302 and extend through the central bore. The 
tubes may come in various lengths and be joined as desired at 306 to reach 
drain blockages. 
The fitting 290 of FIG. 15 includes a closure cap 308 affixed to the 
adapter at its conical surface 300 to provide for positive securement to a 
radiator filling opening 310. This feature is particularly useful in 
dealing with hot or steaming radiators. 
The present invention has been described with particular reference to 
utilizing a household wet/dry vacuum cleaner in usual commercial form. It 
is within the purview of the present invention to provide apparatus for 
opening drains specifically built for the purpose as would be used for 
commercial or industrial applications in which the pressure/vacuum source 
together with the control mechanism are dedicated to drain opening 
applications and are of unitary construction. In such embodiment of the 
invention, a drive motor of greater horsepower is used to achieve higher 
levels of pressure/vacuum than are available with wet/dry vacuum cleaners 
and which are appropriate and required for clearing drains in commercial 
and industrial applications. Similarly, the present invention contemplates 
embodiments of the invention specifically designed for use in purging 
motor vehicle radiators, the cooling systems of marine engines, and so 
forth where pressure/vacuum levels are tailored specifically for these 
applications.