Valve containment bag

A containment bag for installation over a fluid control valve is provided. The valve containment bag is configured to contain leaks emanating from fluid control valves connected in line between an associated first inlet pipe and a second outlet pipe. The inlet pipe and the valve form a first junction and the outlet pipe form a second junction which are to be housed, along with the valve itself, within said bag so that fluid leaking from the junctions leaks into the containment bag. The containment bag is formed of an impermeable fabric which encloses an internal volume sufficient to accommodate the control valve and the associated junctions. The impermeable fabric defines first and second openings between the internal volume and the external environment, the first opening has a diameter substantially equal to the outer diameter of the inlet pipe, and the second opening has a diameter substantially equal to an outer diameter of the outlet pipe. A re-sealable seam extends between the said first and seconds openings so that the bag may be opened and installed over a previously installed control valve. The re-sealable seam may then be re-sealed to close the containment bag, with said first pipe protruding from said first opening and said second pipe protruding from said opening.

BACKGROUND OF THE INVENTION
 The present invention relates to an apparatus for containing fluids leaked
 from control valves, thereby preventing such fluids from contaminating the
 surrounding environment.
 Modern industry abounds with examples wherein liquid chemicals are
 transported, stored, mixed, and otherwise manipulated via interconnected
 networks of pipes, storage tanks, mixers, and the like. Often the flow of
 such chemicals is controlled by the opening and closing of large fluid
 controls valves interposed between sections of pipe.
 In the petroleum industry, for example, oil, gasoline, or other chemicals
 are often stored in large above ground storage tanks. The tanks are filled
 and the chemicals withdrawn via large pipes attached to the sides of the
 tanks. The flow of liquids into and out of the tanks is controlled by
 large shut off valves connected in line with the pipes attached to the
 sides of the tanks.
 A problem with this arrangement and similar arrangements, is that leaks
 often form within the valves and at the joints between the valves and the
 pipes. In many cases, the chemicals leaking from such facilities will have
 a detrimental effect on the surrounding environment. Therefore, it is
 desirable to contain such leaks in order to prevent contamination of the
 surrounding environment. Containment, however, must be achieved in an
 economical manner. Further, because many of the facilities requiring some
 form of valve containment are already in existence, an apparatus for
 containing leaking fluids must be capable of being retrofit onto existing
 facilities. Another desirable feature of a containment apparatus is that
 it allows for visual inspection of the valve in order to determine whether
 or not a leak is present. Finally, an apparatus for containing leaks must
 allow unrestricted operation of the valve being contained. In other words,
 the valve actuator must be accessible for manual and/or automatic
 operation as required by the particular application. Such accessibility
 must be provided without compromising the containment function of the
 containment apparatus.
 SUMMARY OF THE INVENTION
 In light of the background given above, a primary object of the present
 invention is to provide an apparatus for containing fluids that may
 potentially leak from control valves and the piping connected thereto.
 Another object of the present invention is to provide a sealed containment
 apparatus to prevent the collection of rain, snow and other materials
 commonly collected in open containment systems.
 Still another object of the present invention is to provide a valve
 containment bag that may be installed over a valve that has been
 previously installed.
 Still another object of the present invention is to provide a valve
 containment bag wherein the valve actuator protrudes from the bag, and the
 bag forms a liquid tight seal therewith to maintain the leak proof
 integrity of the containment bag.
 All of these objects as well as others which will become apparent upon
 reading the detailed description of the preferred embodiments, are met by
 the valve containment bag and leak containment system herein disclosed.
 In a preferred embodiment of the invention, an apparatus for containing
 fluids leaked from a fluid control valve is provided in the form of a
 bag-like structure formed of an impermeable synthetic fabric. Individual
 fabric panels are joined along a plurality of seams to form an enclosed
 space. In the preferred embodiment the bag has the general shape of a
 short-sided cube, with a pair of large square front and rear panels and
 narrower rectangular panels forming the sides therebetween.
 Each large square panel defines an opening communicating between the
 interior and exterior of the bag. In general, the circular openings are
 chosen to match the perimeter of the pipes attached to the valve, or their
 associated connecting flange. In the preferred embodiment, the openings
 are circular with short fabric collars extending around the perimeters of
 the openings. The collars form an axial surface which may be clamped to
 the outer circumference of a pipe or a pipe's connecting flange. Other
 shaped openings may also be employed in those cases where the associated
 piping has other than a circular cross section. The top of the bag defines
 a third opening. This opening, rather than having a short collar, includes
 a much longer tapered sleeve.
 A first re-sealable liquid tight seam, preferably in the form of a plastic
 zipper, extends between the first opening in the front panel and the
 opening at the end of the tapered sleeve attached to the top of the
 containment bag. A second re-sealable liquid tight seam, similar to the
 first, extends between the second opening in the rear panel and the
 opening at the end of the tapered sleeve. The re-sealable seams extend
 through the tapered sleeve, through the front and rear panels, and through
 the collars surrounding the first and second openings. Thus, when both
 re-sealable seams are opened, a single large opening is formed at the top
 of the bag extending all the way between the first and second openings in
 the front and rear panels. When the re-sealable seams are closed, three
 distinct openings are defined.
 The valve containment bag of the present invention may be installed over a
 fluid control valve that has already been installed between associated
 inlet and outlet pipes. The re-sealable seams are both opened and the bag
 is simply pulled over the valve with the actuator protruding through the
 opening. The bag is oriented such that the inlet pipe extends through the
 first aperture in the front panel, and the outlet pipe extends through the
 second opening in the rear panel. Once the bag has been pulled over the
 valve, the main body of the valve as well as the joints between the valve
 its associated inlet and outlet pipes, are enclosed within the bag. The
 re-sealable seams are then closed over the valve and around the pipes.
 With the re-sealable seams closed, the collars around the first and second
 openings encircle the inlet and outlet pipes, and the tapered sleeve
 encircles the valve actuator. Clamps are then tightened around the collars
 and the tapered sleeve. Gasketing material and caulk may be employed to
 ensure an effective seal between the containment bag and the inlet and
 outlet pipes, and the valve actuator in order to seal the openings around
 the inlet and outlet pipes and the valve actuator.
 In an embodiment of the invention, a system for containing leaks from
 control valves comprises a valve containment bag and a plastic insert
 provided to be placed around an irregularly shaped valve actuator. The
 insert provides a smooth, more regular outer surface for clamping the
 tapered sleeve to form a more reliable seal. Further, a sight glass may be
 installed through one of the panels of the bag to allow an inspector to
 visually determine whether fluid has leaked from the valve. The sight
 glass may be field installed so that it may be placed in the most
 accessible position possible. The sight glass may also be advantageously
 employed as a drain whereby fluid that has leaked into the bag may be
 safely removed and properly discarded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 In FIG. 1 a typical fluid control valve is shown at 100. Valve 100 is
 typical of the type of valves with which the present invention is to be
 employed. Valve 100 is shown installed between an inlet pipe 102 and an
 outlet pipe 104. The valve comprises a main body 106 and an actuator 108.
 The actuator shown includes a manually operated hand-wheel 124, and
 hand-wheel support 126. The manual hand wheel shown in FIG. 1 represents
 only one of many types of actuators that may employed. Many other style
 actuators are available, and the present invention is in no way limited to
 use only with hand wheel type actuators. The actuator 108 is mounted to
 the main body 106 by an actuator receiving flange 122 formed on the main
 body of the valve and a corresponding actuator connecting flange 120
 formed on the actuator itself. The two flanges are mounted together and
 rigidly connected by a series of bolts 114 extending through both flanges
 and secured by nuts 115 on the opposite side.
 Inlet pipe 102 and outlet pipe 104 are connected to the main body 106 in
 similar fashion. Inlet pipe 102 is formed with connecting flange 110, and
 outlet pipe 104 is formed having connecting flange 116. On the main body
 of the valve, the inlet and outlet ports are formed with an inlet port
 connecting flange 112, and an outlet port connecting flange 114,
 respectively. The inlet pipe connecting flange 110 is placed against the
 inlet port connecting flange 112 and the two are joined by bolts 114
 extending through both flanges, and secured by nuts 115. Similarly, outlet
 pipe connecting flange 116 is placed against the outlet port connecting
 flange 118, and the two flanges are bolted together. If leaks develop in
 the valve, they most likely will occur at the joints between the valve and
 the pipes, or between the main body 106 and the actuator 108.
 Turning to FIG. 2, a valve containment bag according to the present
 invention is shown at 150. Containment bag 150 is formed from a number of
 individual impermeable synthetic fabric panels. In the preferred
 embodiment of the invention, the impermeable fabric is formed of a high
 strength reinforcing fabric coated with an overall protective
 multi-polymer. The multi-polymer coating must be well suited for high
 temperature thermal welding, and compounded to resist attack by the
 product being carried the pipes and valves being contained. Also, the
 material must be ultra-violet stable so it will not degrade during its
 service life. In the preferred embodiment, the fabric panels comprise
 PETRO GARD.RTM. VI a high strength impermeable synthetic fabric
 manufactured by MPC Containment Systems, Ltd. of Chicago, Ill. Other
 suitable fabrics presently commercially available include PETRO GARD.RTM.
 X and CHEM GARD.RTM. 14.
 The various fabric panels are joined at impermeable seams formed by a high
 pressure thermal welding process. Adjacent panel edges are placed in
 overlapping engagement, and subsequently heated to melt the polymer
 coating of the fabric. The melted plastic bonds the panels together to
 form a strong leak-proof seam. A cross sectional view of such a seam is
 shown in FIG. 6, wherein a first fabric panel 172 overlaps a second fabric
 panel 174, and seam 176 is formed when the two overlapping sheets are
 welded together.
 Valve containment bag 150 includes a front panel 152 and a corresponding
 rear panel 153. Both the front and the rear panels define openings such as
 front opening 158 shown in FIG. 2. The front and rear openings allow the
 inlet and outlet pipes to pass through the valve containment bag 150. A
 short 160 collar formed of the same impermeable material lines the opening
 158 through front panel 152. A similar collar, though not visible in FIG.
 2, lines the opening in the rear panel 153. The front and rear panels are
 joined at seam 70. A rectangular bottom panel 155 encloses the bottom of
 containment bag 150.
 The top panel is not continuous, but rather includes two separate panels
 156, 157 adjacent the lateral sides of containment bag 150. A large
 opening bounded by the edges of the top panels 156, 157, and the front and
 rear panels 152, 153, is formed at the top of the valve containment bag
 150. A tapered sleeve 162 is attached to the top panels 156, 157 as well
 as to the front and rear panels 152, 153. The tapered sleeve 162 forms a
 flexible transition from the square or rectangular opening formed at the
 top of the containment bag, to a more circular opening 164 at the end of
 the sleeve. The sleeve 162 is thermal welded to the top, front and rear
 panels by the same method described with regard to forming seams 170.
 Two liquid-tight re-sealable seams 166, 168, preferably in the form of
 plastic zipper type fasteners, are formed in the front and rear of sleeve
 162. The front and rear re-sealable seams extend through the full length
 of sleeve 162, through the front and rear panels 152, 153 to the front and
 rear openings respectively. Thus, the first re-sealable seam extends from
 the opening 164 at the end of the sleeve 162, through the sleeve, and
 though the front panel 152 and collar 160. In FIG. 2, the front
 re-sealable seam 166 is shown in an open condition such that a single
 continuous opening is formed at the top of the containment bag. As shown,
 the opening extends all the way between the front opening 158 and the
 sleeve opening 164. The rear re-sealable seam similarly extends from the
 sleeve opening 164, through the sleeve, through rear panel 153 and the
 rear collar to the rear opening (rear collar and rear opening not shown).
 In FIG. 2, the rear re-sealable seam 168 is shown in a closed condition.
 When the re-sealable seams are closed they form a liquid tight barrier
 such that fluid leaked into containment bag 150 cannot escape through the
 re-sealable seams.
 In FIG. 5 a cross sectional view of a plastic zipper is shown. The zipper
 comprises first and second zipper members 130, 132. First zipper member
 130 is thermal welded to a first fabric panel 134, and second zipper
 member 132 is thermal welded to a second fabric panel 136. Zipper members
 130, 132 include identical opposing mating structures. The mating
 structures comprise alternating hooks 138 and grooves 140. The zipper is
 closed by an actuator (not shown) which forces the hooks of each zipper
 member into the grooves of the other. When mated in this manner the hooks
 of each mating surface are held in opposition to one another, and the
 barbed projections 142 of the opposing hooks engage one another to hold
 the zipper in a closed, sealed position.
 Referring now to FIGS. 1, 2 and 4, installation of a valve containment bag
 150 according to the present invention over a control valve that has
 already been connected between corresponding inlet and outlet pipes will
 now be described. With both re-sealable seams 166, 168 open, a single
 continuous opening is formed at the top of the bag, extending from opening
 158 in the front panel 152 to the corresponding opening formed in the rear
 panel 153. This single large opening may be pulled over the valve and pipe
 assembly so that the inlet pipe extends through the front opening 158, and
 the outlet pipe extends throughout the rear opening. The valve actuator
 protrudes through the yet to be closed opening at the top of the
 containment bag. The re-sealable seams 166, 168 may then be closed around
 the valve and pipe assemble. As shown in FIG. 4, the collar 160 lining the
 front opening 158, encircles the inlet pipe connecting flange 110. Though
 not shown, the rear collar lining the rear opening similarly encircles the
 outlet pipe connector flange 116. Beyond the front and rear openings the
 re-sealable seams 166, 168 entirely close and seal the front and rear
 panels, and tapered sleeve 162. Sleeve 162 encircles the actuator
 connecting flange 120, with the actuator itself extending above the
 opening 164 formed at the end of the sleeve.
 Once the valve containment bag has been closed, circular clamps 194 formed
 of metal bands are tightened around the front and rear collars and sleeve
 162. The clamps seal the openings to containment bag 150. Thus, the entire
 valve including both the inlet and outlet joints and the actuator joint,
 are enclosed within the bag. The closed bag forms an impermeable membrane
 completely enveloping the valve and adjacent portions of the inlet and the
 outlet pipes. Any fluids leaked from the valve or the connecting joints
 will be contained within the bag.
 It should be noted that though the preferred embodiment describes front and
 rear collars being clamped to the inlet and outlet pipe connector flanges,
 alternately the collars may be clamped directly to the outer surfaces of
 the pipes themselves. Thus, the containment bag of the present invention
 will function equally well with valves that are connected to their
 associated inlet and outlet pipes in a manner different than that herein
 described.
 An alternate embodiment of the invention comprises a system for containing
 leaks emanating from fluid control valves. The system comprises a valve
 containment bag as previously described, coupled with an insert to be
 placed around the valve's actuator support member. This system is
 especially well adapted for use with valves having actuators with
 irregular surfaces around which it is difficult to clamp and seal the
 impermeable fabric comprising tapered sleeve 162. With valves of this
 type, the insert must be placed around the valve actuator in order to
 provide a smooth, more regular surface for clamping the sleeve. In FIG. 3,
 a valve insert is shown at 180. The insert comprises two similarly shaped
 pieces 182, 184. Each half of the insert includes an internal cavity 186
 configured to receive irregular protruding aspects of the valve actuator.
 The insert pieces further include machined throat portions 190, 192 that
 closely match the contours of a section of the valve actuator. This can
 best be seen in throat portion 192 which includes an internal groove 194
 configured to receive a corresponding ridge formed on the valve actuator.
 Thus, when the two insert halves 182, 184 are placed around the valve
 actuator, a liquid-tight seal is formed between the inner throat portion
 of the insert halves and the valve actuator. A gasket material may be
 included within throat portions 190, 192 to provide a better seal with the
 actuator. The outer perimeter surfaces 196 of the inserts are smooth, with
 no irregular projections or depressions, such that a circular clamp 198,
 similar to those employed in sealing the collars to the inlet and outlet
 pipe connector flanges, may be employed to seal the sleeve around the
 outer surfaces of the insert.
 Finally, as shown in FIGS. 2 and 4, a sight glass 200 may be installed
 through one of the fabric panels comprising valve containment bag 150.
 Sight glasses are known in the art, and many different models are
 commercially available. Any model that provides a liquid tight seal with
 the surrounding fabric, and resists attack by the chemical being contained
 will suffice for the present application. The sight glass allows an
 inspector to visually inspect the contents of the valve containment bag in
 order to assess whether the valve assembly contained therein is leaking.
 The sight glass further provides a port through which leaked fluids may be
 drained from the containment bag without need of removing the bag. The
 sight glass is best installed in the field after the containment bag has
 been properly installed on a valve assembly. By waiting to install the
 sight glass after the bag is in place, the sight glass may be placed in
 the most advantageous position with respect to the surrounding equipment.
 It should be noted that various changes and modifications to the present
 invention may be made by those of ordinary skill in the art without
 departing from the spirit and scope of the present invention which is set
 out in more particular detail in the appended claims. Furthermore, those
 of ordinary skill in the art will appreciate that the foregoing
 description is by way of example only, and is not intended to be limiting
 of the invention as described in such appended claims.