United States Patent Office
3,276,481
APPARATUS FOR CONTROLLING LIQUID FLOW
Carrell S. McNuIty, 35 Beulafa Road, New Britain, Pa.
Filed Aug. 13, 1964, Ser. No. 389,290
1 Claim. (CI. 138—93)
This invention relates to apparatus for stopping the flow of liquid in a conduit and, more particularly, to liquid flow controlling apparatus which is adapted for easy installation in and removal from a conduit through which the liquid flow is to be controlled.
There are many occasions in the design, construction and maintenance of a pipe system, such as a sewer, in which it is necessary to determine the rate of flow of liquid through the individual pipes or conduits of the system. For instance, during the initial construction the tightness of the system must be evaluated to determine whether it meets the criteria set forth in the specifications. In some instances the amount of exfiltration must be determined, while in others it is the amount of infiltration which must be measured. Furthermore, the detection of leaks in a pipe system is usually accomplished by comparing the flow rates at selected points in the system. Before such flow measurements can be accomplished, however, the individual pipeline in which the measurement is to toe made must be isolated, and so the other lines communicating therewith must be plugged.
In the past, plugs made of cast iron have generally been used to stop the flow in sewer pipes. Such prior art plugs are heavy and thus awkward to handle, and a sledge is usually required to install them in a pipe. Furthermore, if the interior of the pipe is rough, caulking is required in order to obtain a positive seal. Moreover, such plugs can only be installed at the open end of a pipe, such as in a manhole. If there is a sufficient head of liquid behind these plugs, they are dislodged and may become jammed somewhere between manholes, in which case they must be dug out at considerable expense. Finally, it is not only difficult but also unsanitary to install conventional plugs in sewer lines in which there is an appreciable flow.
Accordingly, it is an object of the present invention to overcome the above-mentioned difficulties of conventional techniques for controlling the flow of liquid in a conduit.
Another object of the invention is to provide a novel apparatus which may be easily installed in and removed from a conduit through which the liquid flow is to be controlled.
A further object of the invention is to provide a novel liquid flow controlling apparatus which may be readily installed anywhere along the inside of a conduit.
These and other objects and advantages of the invention are attained by providing an inflatable bag having a valve through which fluid from any suitable source may be introduced. The ratio of the length of the bag to the diameter of the conduit for which the bag is designed is preferably such that a relatively low pressure in the bag positively seals the bag against a rough interior surface of the conduit in the presence of a relatively large head of liquid. There are provided at each end of the bag a pair of fastening terminals, to which tie lines may be secured, so that the deflated bag may be positioned where desired in the conduit, after which the bag may be inflated from a remote location to plug the conduit.
All of the above is more fully explained in the detailed description of the embodiments of the invention which follow, this description being illustrated by the accompanying drawings wherein:
FIG. 1 is a view in perspective of one embodiment of a typical apparatus for controlling the flow of liquid in a conduit (shown in phantom) according to the present invention, the apparatus being connected to a hand pump;
FIG. 2 is a view in perspective showing the apparatus of FIG. 1 deflated and rolled up; and
FIG. 3 is a plan view of another embodiment of the apparatus according to the invention, showing an alterna
5 tive form of fastening terminals, the apparatus being connected to a pressure tank.
In the representative embodiment of the invention shown by way of example in FIGS. 1 and 2, the liquid flow controlling apparatus 10 is disposed in the open end
10 11 of a conduit 12 (shown in phantom). The apparatus 10 includes a bag 13, preferably constructed of an elastomeric material such as rubber. Mounted on the bag 13 at one end thereof is a check valve 14 (which is preferably spring biased), through which a pressure fluid such
15 as compressed air may be introduced into and maintained within the interior of the bag 13. When desired, the valve 14 may be actuated against the action of the biasing spring to deflate the bag. The apparatus 10 is shown connected through a hose 15 to a hand pump 16, toy means of which
20 the bag may be inflated in a conventional manner.
Each end of the bag 13 is formed into a tab portion 17 which is provided with a pair of spaced holes, each preferably fitted with a reinforcing ring 19 of suitable material, the reinforced holes comprising a pair of spaced
25 fastening terminals 20, to which a tie line 21 may be secured. These terminals are preferably located substantially at the lateral edges of the tab portion 17 for reasons to be explained presently. The bag 13 is preferably so shaped that when deflated
30 it assumes a generally rectangular shape, so that it may be readily rolled up into a compact size, as illustrated in FIG. 2. A .pair of elastic bands or cords 22, for example, may be used to retain the bag in the form illustrated. It can be seen that the apparatus is easily held
35 in one hand or could be carried in a hip pocket when climbing into a manhole, for example.
Another embodiment of the invention, is illustrated in FIG. 3. Like part's are designated with the same numbers used in the first embodiment, primes being added
40 in FIG. 3. The apparatus of FIG. 3 differs from the first embodiment in the form taken by the fastening terminals 20'. The bag 13' is formed with a pair of spaced tabs 23 which receive the reinforcing rings 19'. Tie lines 24 and 25 may be secured to the ends of .the bag, as il
45 lustrated, for reasons to be explained hereinafter. The bag 13' may be connected through the hose 15' to a pressure tank 26 in order to inflate the bag.
It is to be understood that the apparatus 10 or 10' could be supplied in a wide range of sizes to accommo
50 date the various size pipes of a system. Thus, a family of pipe stoppers could be provided for the standard sewer pipe diameters from eight inches to 48 inches or larger, for example. Regardless of the size of the stopper, a shape is maintained in which the ratio of the length of the
55 deflated bag to the diameter of the conduit for which the bag is designed is between about two to one and three to one, so that an inflation pressure of only a few pounds per square inch insures positive contact between the lateral wall of the bag and the interior pipe wall along a length
60 of pipe approximately twice the magnitude of the pipe diameter. As a consequence, the pipe is positively sealed even though the interior surface be rough, and an inflation pressure of less than four pounds per square inch secures the stopper in a pipe against the expelling thrust
65 of a 20 foot head of liquid.
If the open end of a pipe is to be plugged, the deflated bag is inserted into the pipe and inflated by the hand pump 16, for example. The bag may be deflated and the apparatus quickly removed from the conduit without
70 any danger to the operator of being splashed from backedup sewage. For example, .by connecting a hose provided with a valve at the free end to the valve 14 so as to
3,276,
