GB2358048A

GB2358048A - Improvements relating to hydrants

Info

Publication number: GB2358048A
Application number: GB9926488A
Authority: GB
Inventors: Mark Syrewicz Lawson
Original assignee: Glenfield and Kennedy Ltd
Current assignee: Glenfield and Kennedy Ltd
Priority date: 1999-11-10
Filing date: 1999-11-10
Publication date: 2001-07-11
Also published as: GB9926488D0

Abstract

A fire hydrant 10 a cover 14 and an outlet 16 fixed to a body 12 by means of respective resilient seals 46, 47 and retainers 48, 49. The seals are compressible to allow fitting of the retainers around the cover 14 or outlet 16 in the body. The retainers 48, 49 are visible from the hydrant exterior and may be reflective and of different sizes to allow rapid location and identification of the cover 14 and outlet 16 portions of the hydrant 10 in conditions of low visibility. A valve stem 36, for operation of a stopper 26 to open and close the hydrant 10, bears a key-operated cap 40, which is retained on the stem 36 by means of a circlip-and-groove arrangement (60 - 62, Fig.5).

Description

2358048 IMPROVEMENTS RELATING TO HYDRANTS The present invention relates to

improvements in the construction and assembly of hydrants.

Hydrants are often located at a number of points around a town or city, in order to provide ready access to a water supply for, for example, firefighters.

Conventional fire hydrants include a hollow cast body for mounting to a pipe coupled to a water main. The body defines an inlet which may be opened and closed by vertical movement of a valve stopper which engages a gunmetal valve seat around the inlet opening. The stopper, and the stopper lifting arrangement, is retained by a cast cover which is bolted to the hydrant body. A valve stem extends t-hrough the cover, the seals between the stem and the cover being retained by a gland retainer bolted to the cover.

is The lower end of the stem is threaded and engages a trapped nut coupled to the stopper, such that rotation of the stem causes the stopper to rise or fall. The upper end of the stem is f itted with a cap, typically fixed to the stem by a grub screw or bolt, the cap profile being selected to match a key provided to authorised personnel to permit operation of the hydrant.

A gunmetal outlet piece defining a coarse thread is bolted to the outlet: opening of the hydrant body, to provide a vertically extending outlet from the hydrant. In use, the lower end of a standpipe is screwed to the outlet 2 piece and extends above ground, the upper end of the standpipe being provided with a coupling arrangement for one or more f ire hoses; in the United Kingdom, hydrants are typically located in chambers below ground level and are accessed via a metal cover plate.

Existing hydrants are vulnerable to attack by vandals.

The outlet piece is of gunmetal and therefore has a relatively high scrap value. The piece is attached to the hydrant body by bolts and may therefore be removed from the hydrant using readily available tools; unfortunately, it is common for outlet -Qieces to be stolen from hydrants.

Similarly, the cast iron cover is bolted to the hydrant body, the gland retainer bolted to the cover, and the can is likewise bolted to the valve stem; these parts may be is removed by vandals without great difficulty. In addition to the expense and inconvenience of having to replace and repair these parts, it may only become apparent that a hydrant has been vandalised in an emergency situation, where the resulting delay in accessing the mains water supply may have significant and even fatal consequences.

In addition, tightening of the various retaining bolts while assembling, and then subsequently maintaining the hydrant, often damages the protective coaings of the hydrant parts, facil.itating corrosion of the exposed metal.

It is among the objects of the present invention to alleviate or obviate these and other disadvantages of conventional hvdrants.

According to a first aspect of the present invention, 3 there is provided a hydrant comprising a body, a cover for mounting on the body, a compressible seal for location between the cover and the body, and a retainer for location between the body and the cover, the retainer being locatable between the body and the cover following an initial compression of the seal by application of a force producing relative axial movement of the body and the cover and the retainer maintaining a lesser degree of compression of the seal on release of said force.

According to a further aspect of the present invention, there is provided a hydrant comprising a body, an outlet for mounting on the body, a compressible seal for location between the outlet and the body, and a retainer for location between the body and the outlet, the retainer is being locatable between the body and the outlet following an initial compression of the seal by application of a force producing relative axial movement of the body and the outlet, and the retainer maintaining a lesser degree of compression of the seal on release of said force.

These arrangements retain the outlet or cover on the hydrant without the need for external fasteners such as bolts or the like, and make it difficult. to remove C-he outlet or cover once in place. Thus, these arrangements render the hydrant: more resistant to vandalism. The absence of bolts or other external fasteners requiring tightening also reduces the risk of damaging protect:ive coatings on the hydrant during assembly and subsequent inspection or maintenance. These arrangements also reduce 4 the time required to assemble the hydrant and the number of parts used in the manufacture of the hydrant: the body, the seal, and the cover or outlet may be placed in a press to compress the seal, and the retainer fitted before releasing the press; this may be accomplished more quickly than a conventional assembly operation requiring placement and tightening of a number of nuts and bolts.

Preferably, both aspects of the invention are combined in a hydrant, that is a compressible seal and a retainer are provided for each of c-he cover and the outlet of a hydrant.

Preferably, the retainer is in at least two parts, to facilitate assembly of the hydrant. Preferably, the retainer is circular, and may be formed of two semL circular parts.

Preferably, the retainer is located so as to be at least partly visible from the exterior of the hydrant, and most preferably the retainer is visible from above. Most preferably, the retainer i S highly reflective.

Alternatively, the retainer may be fluorescent, or vividly coloured.

According to a 4:

further aspect of t: he presen- invention, there is provided a valve seal arrangement for use with. a valve comprising a body and a cover, the valve seal arrangement comprisi-a a comnressible seal for location between a bodv and a cover, and a retainer for location between the body and the cover, the retainer being locatable between the body and L-he cover following an initial compression of the seal by application of a force producing relative axial movement of the body and the cover and the retainer maintaining a lesser degree of compression of the seal on release of said force.

According to a further aspect of the present invention there is provided a hydrant- comprising a body, an outlet for mounting on the body, and a retainer mounted between the body and the outlet, the retainer being at least partly visible from the exterior of the hydrant.

This aspect of the present invention facilitates location of the outlet by firefighters in emergency situations, as the visible retainer will allow the outlet location to be easily identified, even in poor visibility situations.

Preferably, the hydrant is provided with a cover and a retainer between the body and the cover, the cover retainer also being visible from the exterior of the hydrant. In another aspect of the invention only the cover is provided with a visible retainer.

Preferably, the retainer is highly reflective; in low light conditions the retainer will be easily identified by shining a torch or flashlight towards the hydrant.

Preferably, the retainer is substantially circular, or defines another closed or substantially closed form, such that an individual observing the hydrant from above will see a circle or the like surrounding the outlet. If both the cover and the outlet include such a retainer, preferably the two retainers are distinguishable by size 6 and/or colour.

The preferred embodiment of this aspect of the invention provides a convenient external marking on the hydrant which is easily visible even in poor conditions, and allows the hydrant cover and the outlet to be rapidly located by a firefighter; a person viewing the hydrant from above will observe a pair of circles, targeting the cover and outlet: for rapid location of outlet hoses and hydrant operating keys.

other aspects of the invention relate to the provision O-L other means for identifying the location of a hydrant outlet or cover, for example a reflective or fluorescent marking or member on the hydrant body or outlet.

According to a further aspect of the invention there is is provided a hydrant comprising a body, a valve stem extending into the body and a key-engaging cap mounted on the valve stem, at least one of ---he cap and the valve stem being provided a groove, and a sprung retainer for location in the groove and serving to retain the cap on the valve stem.

Preferably, both the valve stem and the cap define alignable grooves.

Preferably, the sprung retainer -i S a circlic).

Alternatively, sprung dogs or other ret:ainers may be used.

Preferably, the val,,,e stem has a rapered upper end, to facilitate location of the cap and the sprung ret-ainer thereon.

This arrangement facilitates rapid assembly of the cap 7 and stem, and it is then difficult to remove the cap from the valve stem without special tools, thereby protecting the hydrant against vandalism.

According to a still further aspect of the present invention there is provided a stem seal arrangement for a valve, the arrangement comprising a stem incorporating a collar portion for location within a valve body, a retaining member for engaging the stem to one side of the collar to retain the stem relative to a valve cover, and at least one seal for mounting on the stem to the other side of the collar to provide a seal between the stem and the valve cover.

Preferably, the retaining member is a clip, most preferably a spring clip.

is Preferably. the at least one seal is an 0-ring seal.

Preferably, the arrangement further comprises a thrust washer located between the collar and the seal.

Preferably, the arrangement further comprises a bearing located adjacent the seal.

Preferably, the arrangement comprises two seals separated by a spacer.

According to a yet further aspect of the present invention, there is provided a hydrant comprising a body and a valve stem extending into the body, the valve stem incorporating a collar portion for location within the body, a retaining member for location within the body and for engaging the stem to one side of the collar to retain the stem relative to the valve body, and at least one seal 8 mounted on the stem to the oth-er side of the collar for providing a seal between the stem and the valve body.

These and other aspects of the invention will now be described by way of example only with reference to the accompanying Figures, in which:

Figure 1 is a cutaway per=ective view of a fire hydrant in accordance with a preferred embodiment of the present invention; Figure 2 is a side view of the fire hydrant of Figure 1; Figure 3 is an exploded cross sectional view of the body, cover and outlet piece of the filre hydrant of Figure 11 Figure 4 is an enlarged sectional scrap view of a part is of the outlet piece and body of the fire hydrant of Figure 1; and Figure 5 is an exploded side view of the valve stem and cap of the f ire hydrant of Figure 1.

Referring first to Figures 1 and 2 of the drawings, there is shown a fire hydrant 10 incorporating embodiments of the various aspects of the present invention, as will be described in greater detail below. The hydrant 10 comprises jA hollow casr- iron body 12, a cast iron bonnet or cover 14 and a gunmetal outlet- piece 16. The body 12 defines a fluid passage 18 leading from an inlet 20 to the outlet piece 16. A flange 22 around the inlet 20 allows the body 12 to be bolted to a f langed pipe (not shown) leading from a water main.

9 The body inlet 20 is provided with a gunmetal seat 24 for cooperating with a rubbercovered stopper 26 provided on the lower end of a valve centre 28. The upper end of the valve centre 28 defines a recess to retain a valve stem-engaging nut 32, and a pair of radially extending lugs 34 which engage corresponding grooves 35 (Figure 3) on the body 12.

A valve stem 36, provided with appropriate seals and retainers 38, extends through the cover 14 to engage the nut 32, such that rotation of the stem 36 will cause the valve centre 28 and thus the stopper 26 to rise and fall and thus open and close the inlet 20. A cap 40 is fixed to the upper end of the valve stem 36 and is dimensioned to cooperate with hydrant -operating keys (not shown) as issued to authorised personnel.

The outlet piece 16 defines a coarse thread 42 for engaging the lower end of a standpipe (not shown) carried by firefighters and the like to provide an above ground coupling location for fire hoses. In Figure 1 the outlet piece 16 is shown fitted with a removable protective cover 44 for preventing ingress of dirt and debris into the hydrant body 12.

Both the cover 14 and the outlet piece 16 are f ixed relative to the body 12 by a respective resilient seal 46, 47 and retainer 48, 49 arrangement, as shown in more detail in Figures 3 and 4 of the drawings. The body 12 def ines mouths 50, 51 to receive the cover 14 and the outlet piece 16, each mouth 50, 51 defining a seal-retaining lip 52, 53 and a retainer-holding groove 54, 55. Each of the cover 14 and the outlet piece 16 define a lip 56, 57 for engaging the respective seal 46, 47 and retainer 48, 49.

The assembly of the ourlet piece 16 and body 12 will now be described, the assembly of t-h-e cover 14 and the body 12 being a very similar operation. 'I'he body 12 and the outlet piece 16 are placed in a press (not shown), with the seal 47 positioned on the lip 53. The outlet piece 16 is then pressed into the body 12, with an applied force of between two and three tonnes, to compress the seal 47. The retainer 49, which is in two semicircular narts, is then placed in the groove 55 above the outlet piece lip 57, and the press released. The seal 47 expands and traps the retainer 49 between the body 12 and the outlet piece 16.

is The assembly operation may thus be carried relatively quickly, and using relatively few parts. Further, once assembled and installed, unauthorised disassembly, for example to remove the outlet piece 16 from the body 1-2, is all but impossible. Also, as is evident from Figure 2, the assembled hydrant is physically compact and has a very low profile and thus may be accommodated within a relatively small chamber, reducing the excavation and related works necessary to install or replace a hydrant.

The retainers 48, 49 are of a reflective material and, as is apparent from -nhe Figures, are visible from above the hydrant. Thus, when a firefigh7-er opens a hydrant cover plate, the retainers 48, 49 will be immediately visible as circles surrounding the cover 14 and 11 the outlet piece 16. These circles provide easily identifiable ',targets", facilitating location of the outlet piece thread 42 (within the smaller "target") and the cap (within the larger "target").

Reference is now made to Figure 5 of the drawings, which illustrates the valve stem 36 and cap 40. Both the stem 36 and cap 40 define circumferential grooves 60, 61 which, in the assembled hydrant, are aligned and occupied by a circlip 62. The upper end of the stem 36 is tapered such that the circlip 62 and cap 40 may simply be pushed downward onto the stem until the circlip 62 snaps into the groove 60. once in place, the cap 40 may only be removed by means of a specially adapted tool, thus rendering the cap 40 resistant to unauthorised removal.

The figure also shows the seals and retainers 38 of the stem 36 in greater detail. The stem 36 includes an integral collar 64, below. which is mounted a sprung retainer clip 66, which serves to retain the stem 36 in the body of the hydrant. Mounted above the collar 64, from bottom to top, are a thrust washer 68, first 0-ring seal 70, a spacer 72, second 0-ring seal 74, and a bearincr 76.

The whole arrangement enables the stem 36 to be mounted and secured in the hydrant from below, so reducing the risk of unauthorised access and removal from above.

It will be understood that the foregoing is for illustrative purposes only, and that various modifications and improvements may be made to the apparatus and methods herein described without departing f rom the scope of the invention.

12

Claims

1 - A hydrant comprising a body, a cover for mounting on the body, a compressible seal for location between the cover and the body, and a retainer for location between the body and the cover, the retainer being locatable between the body and the cover following an initial compression of the seal by application of a force produCing relative axial movement of the bodv and the cover and the retainer maintaining a lesser degree of compression of the seal on release of said force.

2. A hydrant comprising a body, an outlet for mounting on the body, a compressible seal for location between the outlet and the body, and a retainer for location between the body and the our-let, the retainer being locatable is between the body and the outlet following an initial compression of the seal by application of a force producing relative axial movement of rhe body and the outlet, and the rezainer maintain-Ing a lesser degree of compression of the seal on release of said force.

3. A hydrant according to claim 1 or claim 2 wherein a compressible seal and a retainer are provided for each of a cover and an outlet of the hydrant.

4. A hydrant according to any preceding claim wherein the 13 retainer is in at least two parts.

5. A hydrant according to claim 4, wherein the retainer is circular, and is formed of two semi-circular parts.

6. A hydrant according to any preceding claim wherein the retainer is located so as to be least partly. visible f rom the exterior of the hydrant.

7. A hydrant according to claim 6 wherein the retainer is visible from above.

8. A hydrant according to claim 6 or claim 7 wherein the retainer is highly reflective.

9. A hydrant according to claim 6 or claim 7 wherein the retainer is fluorescent.

10. A valve seal arrangement for use with a valve comprising a body and a cover, the valve seal arrangement comprising a compressible seal for location between a body and a cover, and a retainer for location between the body and the cover, the retainer being locatable between the body and the cover following an initial compression of the seal by application of a force producing relative axial movement of the body and the cover and the retainer maintaining a lesser degree of compression of the seal on release of said force.

14 11. A hydrant comprising a body, an outlet for mounting on the body, and a retainer mounted between the body and Ehe outlet, the retainer being at least partly visible from the exterior of the hydrant.

12. A hydrant according to claim 11 wherein the hydrant is provided with a cover and a retainer between the body and the cover, the cover retainer also being visible from the exterior of the hydrant. 13- A hydrant according to claim 11 or claim 12 wherein 10 the retainer is highly reflective. 14. A hydrant according to any one of claims 11 to 13 wherein the retainer defines a closed or substantialIv closed form. 15. A hydrant according to claim!2, having an cutler15 retainer and a cover retainer, wherein the two retainers are distinguishable by at least one of size and colour. 16. A hydrant comprising a body, a valve stem extending into the body and a key-engaging cap mounted on the valve stern, at least one of the cap and the valve stem being 20 provided with a groove, and a sprung retainer for location in the groove and serving to retain the cap on the valve stem. 17. A hydrant according tO claim 16 wherein both the valve is stem and the cap define alignable grooves.

18. A hydrant according to claim 16 or 17 wherein the valve stem has a tapered upper end, to facilitate location of the cap and the sprung retainer thereon.

19. A stem seal arrangement for a valve, the arrangement comprising a stem incorporating a collar portion for location within a valve body, a retaining member for engaging the stem to one side of the collar to retain the stem relative to a valve cover, and at least one seal for 10 mounting on the stem to the other side of the collar to provide a seal between the stem and the valve cover. 20. A hydrant comprising a body and a valve stem extending into the body, the valve stem incorporating a collar portion for location within the body, a retaining member for location within the body and for engaging the stem to one side of the collar to retain the stem relative to the valve body, and at least one seal mounted on the stem to the other side of the collar for providing a seal between the stem and the valve body.