GB1560998A - Plastics valve with positioning handle - Google Patents

Abstract

The actuating device of the valve (12) has an actuating extension (31) which is connected to the valve-closing element (16) via a connecting section (36). The connecting section is designed in such a way that it acts as a predetermined breaking point before impermissibly high forces can act on the valve-closing element, causing leaks. By means of a particular arrangement of the working surfaces of the actuating extension, which extend parallel to the axis of rotation, the valve can be operated by various tools. Towards the top, the actuating extension (31) has bevelled surfaces which serve to deflect impact forces. The actuating device is particularly advantageous for valves made of plastic installed in underground gas distribution pipes. <IMAGE>

Description

(54) PLASTICS VALVE WITH POSITIONING HANDLE (71) We, ROCKWELL INTERNATIONAL CORPORATION, a corporation of the State of Delaware, U.S.A., having a place of business at 600 Grant Street, Pittsburgh, Pennsylvania, U.S.A., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed. to be particularly described in and by the following statement: This invention relates to plastics valves.

There is an increasing demand for plastics valves to be utilized in association with plastics pipe in the gas distribution field. It is of continuing concern that these valves be designed to ensure that the system integrity will be maintained under adverse operating conditions. United States Federal operating standards, for example. require plastics pipe to be able to withstand pressures up to about 100 p.s.i. under operating temperatures ranging from - 200 F to + 1000 F. Valves utilized with this pipe should satisfy similar requirements.

Throughout this range of temperatures and pressures there is created a change in the characteristics of the plastics which complicates the basic problem of system reliability.

Specifically, it has been recognized that if the valve became jammed during efforts to open or close it, a situation could develop whereby a loss of system integrity might follow. Customarily, these valves are located underground and are operated by field service personnel with the variety of metal, torque applying tools. It is felt that if a valve became jammed, these rugged tools could be utilized to apply an excessive force to the isolation member and the body which could destroy the plastics valve or pipe, A crack or fracture in the isolation member, body or pipe could allow an uncontrolled escape of gas which would endanger personnel and property in the area.

The object of the invention is to provide a valve positioning handle which can be operated without risk of damage lo the valve or pipe.

According to the invention there is provided a valve for use in a pressurised fluid distribution pipe, said valve having a plastics body; a plastics isolation means disposed therein for rotation about a central axis; and a valve positioning handle comprising an extended fitting centrally aligned with said axis and having working surfaces thereon for rotational driving engagement by a torque applying tool, and a connecting section integrally joining said extended fitting and an end of said isolation means, said section having predetermined cross-sectional dimensions in a plane perpendicular to said axis to ensure failure of said section prior to generation of forces caused by said torque applying tool being utilised to rolate said extended fitting which would be so excessive as to cause destruction or damage of the valve body or isolation means.

A preferred embodiment of the invention is now more particularly described with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a valve positioning handle, Figure 2 is a top view of the handle shown in Figure 1, Figure 3 is a side view of the handle shown in Figure 1, Figure 4 is an end view of the handle shown in Figure 1, including one type of isolation member on which it may be mounted.

As seen in a perspective view in Figure 1, a preferred valve positioning handle 10 is utilized to open and close a valve 12. Tlle valve 12 includes a body 14 and a fluid isolation member 16 which is disposed within the body 14 for rotation about a central axis of the valve 12. The valve 12 is formed of a plastics material and is of the type which can be utilized in a pressurized gas distribution piping (not shown) which is commonly located underground and sub- jected to varying environmental conditions.

Also shown in Figure 1 in phantom are two torque applying tools most often utilized by field service personnel in the opera tion of isolation valves in this type of system. A first tool 18 is formed of heavy metal and typically includes a T handle (not shown) connected to an extended shaft 20. An inverted U-shaped wrench 22 is centrally aligned with the shaft 20 to include a parallel pair of depending, separated leg planes 24. The leg planes 24 are to be positioned at opposite working sides of a valve operating handle to enable the service personnel to rotate the tool 18 for selective positioning of a valve. A second tool 26 is also formed of metal and includes an operating shaft (not shown) which terminates at a square-shaped wrench 28 at its lower end.

The square-shaped wrench 28 has four side planes 30 of equal length, usually two inches, to be positioned about a matching square valve fitting for rotation of the valve isolation member. The tools 18 and 26 have heretofore been used on valves having different operating fittings according to size and/or manufacturer's design but are both quite commonly used in the gas distribution field.

As seen in Figures 1 through 4, the preferred valve positioning handle 10 includes an extended fitting 31 which is adapted to selectively accommodate both torque applying tools 18 and 26. The extended fitting 31 is provided a plurality of working surfaces which are generally parallel with the valve axis and specifically includes a pair of opposed surfaces 32 against which each leg plane 24 can be located for rotation by the first tool 18. Other working surfaces include a quadruplet of surfaces 34 which are properly spaced and oriented to respectively receive thereby each side plane 30 of the scond tool 26 should it be utilized for valve operation.

As discussed hereinabove, it is of concern that while the heavy, metal tools 18 and 26 are capable of properly positioning a valve, they are structurally capable of being used to generate an excessive force during rotation which could destroy a plastics valve or the plastics distribution piping extending at either side thereof. This would be equally true if some other rugged- torque applying tool, such as one with an adjustable wrench fitting, were alternatively employed.

Accordingly, the preferred handle 10 includes a connecting section 36 between the extended fitting 31 and the end 38 of the isolation member 16 on which the handle 10 is mounted. The connecting section 36 is designed to fail under torsional stress before the tool could be utilized on the extended fitting 31 to generate the undesired excessive force within the valve 12 or the pipe. It is known that the maximum torque about a given axis which a section can withstand is a function of the material and the cross-sectional dimensions of the section relative the axis in a plane which is perpendicular to the axis. For a preselected material, the ultimate shear stress can be obtained from an engineering material handbook.When the cross-sectional dimensions relative to the axis are predetermined, the polar moment of inertia and the distance from the axis to the most extreme portion of the section (the point at which shearing will begin) can be determined. The ultimate shear stress, the polar moment of inertia and this distance are used to calculate the maximum torque which the section can withstand.

By way of example, a typical valve configuration might include an isolation member 14 in the form of a plastics cylindrical plug 40 as shown in Figure 4. Preferably, the plug 40 and the handle 10 are integrally formed by molding of the same plastics material. Although not shown in the drawings, it was determined by accepted engineering analysis and calculations that both the body 14 and the piping were stronger than the plug and that neither would, in this configuration, be the first element to fail under an excessive force which might be generated by use of the tool. The plug 40 includes a port 42 which is aligned with the passages in the pipe for flow through the valve 12 when in the opened position.A pair of recesses 44 at opposite sides of the plug 40 respectively receive a pair of resiliently deformable sealing members (not shown since that would offer little resistance to torsional failure of the plug 40) which sealing members are to be aligned with the pipe passages when the valve 12 is closed to prevent fluid flow therethrough. The plug 40 therefore has its smallest cross-sectional area at an intermediate plane A where two separated, structural portions 46 join the opposite ends of the plug 40 and would fail in this region if subjected to an excessive torque. The portion of the connecting section 36 at which shearing should first occur under torsional stress is shown in Figure 4 at plane B.

Mathematical shearing analysis was conducted for a plug and handle configuration formed of plastics material having at least an ultimate shear stress of approximately 20,000 p.s.i. throughout the expected operating temperatures. The plug 40 had a diameter of about two inches and the connection section 36 has a length of about 2.35 inches and an effective width of about .25 inches. The results of the analysis indicated that the connecting section 36 would shear at plane B with a torque of about 76 footpounds but that 128 foot-pounds torque would be required to shear the plug along plane A where the reduced cross section is located.Laboratory tests were then con ducted on such a plug and handle and it was found that the average torque required to break the connecting section was about 80 foot-pounds while about 200 foot-pounds were required for the plug 40 in the region of the port 42.

While the analysis and tests above were conducted for a configuration which exemplifies the purpose of the invention, it should be apparent that a connecting section of different shape or material might be utilized to protect any number of valve configurations. For example, the valve might be a ball valve, or the valve body might be the weakest element, or the isolation member might be formed of a different plastics material from the handle. One skilled in the valve manufacture and construction art should be capable of analyzing the particular configuration to ensure that the connecting section would fail prior to destruction of the valve or pipe.

While breaking the valve handle, even if valve operation is lost, is obviously preferable to having a dangerous loss of system integrity which would allow the escape of gas, failure of the connecting section 36 is not desired unless needed for this purpose.

Unfortunately, designed weakening of the connecting section 36 to ensure failure under excessive torque, leaves it vulnerable to damage by the application of other types of force. Being located underground and being operated by heavy torque applying tools makes the handle particularly susceptible to impact force from any number of sources from above the valve, such as might occur from a dropped tool. The possibility of undesired breakage is increased at lower temperatures as the plastics becomes more brittle. It is therefore desirable to deflect any tool, rock or other object from direct impact on the handle if dropped from above.

Therefore, a plurality of facets 48, 50 and 52 are located at the top of the extended fitting 31 and are downwardly inclined from the valve axis for this purpose. Since an impact force might be created by field service personnel striking the handle 10 with a tool when it is not properly aligned with the working surfaces, the facets 48 and 50 are respectively aligned with the working surfaces 32 and 34 to facilitate alignment and decrease the likelihood of damage by this occurrence.

There are in the preferred valve positioning handle 10 additional features which facilitate reliable valve operation. It is not uncommon for a pair of position stop devices 54 to be provided on the body 14 to ensure the valve is in the proper opened or closed position as desired after rotation. A position indicator is usually mounted on the isolation member to make contact with the stop device 54. In the preferred handle 10, a pair of position indicating tabs 56 are provided for this purpose and are integrally formed with and extend from the connecting section 36. In Figure 1, the valve 12 is shown in the opened position as evidenced by the tabs 56 being aligned with flow direction arrows 58 formed on the body 14.It is also desirable, as with the handle 10, to prevent damage to the tabs 56 by a tool being dropped or roughly positioned around the extended fitting 31. Since a blow to the handle 10 or the isolation member 16 might cause a slight, rapid axial movement of the isolation member 16 with respect to the body 14. The tabs 56 are axially separated from the body 14, as at 60, to allow limited axial movement thereof free of contact with the body 14 which could break the tabs 56. Additionally, the tabs 56 are axially lower than the extended upper surfaces 62 of the position stop devices 54. This positioning insures that when the tool 26 is used, it will make contact with the surfaces 62 rather than with the tabs 56 during valve positioning when the tabs 56 could otherwise be damaged or broken.

The valve handle configuration referred to above, providing for actuation by either type of wrench, is described and claimed in our co-pending Patent Application No.

42995/78 (Serial No. 1560999) of even date herewith.

WHAT WE CLAIM IS:- 1. A valve for use in a pressurised fluid distribution pipe, said valve having a plastics body; plastics fluid isolation means disposed therein for rotation about a central axis; and a valve positioning handle comprising an extended fitting centrally aligned with said axis and having working surfaces thereon for rotational driving engagement by a torque applying tool; and a connecting section integrally joining said extended fitting and an end of said isolation means, said section having predetermined crosssectional dimensions in a plane perpendicular to said axis to ensure failure of said section prior to generation of forces caused by said torque applying tool being utilised to rotate said extended fitting which would be so excessive as to cause destruction or damage of the valve body or isolation means.

2. The valve as set forth in Claim 1, wherein said body of said valve includes a pair of position stop means, and said handle includes a pair of position indicating tabs aligned with said respective stop means during rotation to limit rotation of said isolation means between an opened and a closed position.

3. The valve as set forth in Claim 2, wherein said position indicating tabs are integrally formed, radial extensions of said connecting section.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   ducted on such a plug and handle and it was found that the average torque required to break the connecting section was about 80 foot-pounds while about 200 foot-pounds were required for the plug 40 in the region of the port 42.

   While the analysis and tests above were conducted for a configuration which exemplifies the purpose of the invention, it should be apparent that a connecting section of different shape or material might be utilized to protect any number of valve configurations. For example, the valve might be a ball valve, or the valve body might be the weakest element, or the isolation member might be formed of a different plastics material from the handle. One skilled in the valve manufacture and construction art should be capable of analyzing the particular configuration to ensure that the connecting section would fail prior to destruction of the valve or pipe.

   While breaking the valve handle, even if valve operation is lost, is obviously preferable to having a dangerous loss of system integrity which would allow the escape of gas, failure of the connecting section 36 is not desired unless needed for this purpose.

   Unfortunately, designed weakening of the connecting section 36 to ensure failure under excessive torque, leaves it vulnerable to damage by the application of other types of force. Being located underground and being operated by heavy torque applying tools makes the handle particularly susceptible to impact force from any number of sources from above the valve, such as might occur from a dropped tool. The possibility of undesired breakage is increased at lower temperatures as the plastics becomes more brittle. It is therefore desirable to deflect any tool, rock or other object from direct impact on the handle if dropped from above.

   Therefore, a plurality of facets 48, 50 and 52 are located at the top of the extended fitting 31 and are downwardly inclined from the valve axis for this purpose. Since an impact force might be created by field service personnel striking the handle 10 with a tool when it is not properly aligned with the working surfaces, the facets 48 and 50 are respectively aligned with the working surfaces 32 and 34 to facilitate alignment and decrease the likelihood of damage by this occurrence.

   There are in the preferred valve positioning handle 10 additional features which facilitate reliable valve operation. It is not uncommon for a pair of position stop devices 54 to be provided on the body 14 to ensure the valve is in the proper opened or closed position as desired after rotation. A position indicator is usually mounted on the isolation member to make contact with the stop device 54. In the preferred handle 10, a pair of position indicating tabs 56 are provided for this purpose and are integrally formed with and extend from the connecting section 36. In Figure 1, the valve 12 is shown in the opened position as evidenced by the tabs 56 being aligned with flow direction arrows 58 formed on the body 14.It is also desirable, as with the handle 10, to prevent damage to the tabs 56 by a tool being dropped or roughly positioned around the extended fitting 31. Since a blow to the handle 10 or the isolation member 16 might cause a slight, rapid axial movement of the isolation member 16 with respect to the body 14. The tabs 56 are axially separated from the body 14, as at 60, to allow limited axial movement thereof free of contact with the body 14 which could break the tabs 56. Additionally, the tabs 56 are axially lower than the extended upper surfaces 62 of the position stop devices 54. This positioning insures that when the tool 26 is used, it will make contact with the surfaces 62 rather than with the tabs 56 during valve positioning when the tabs 56 could otherwise be damaged or broken.

   The valve handle configuration referred to above, providing for actuation by either type of wrench, is described and claimed in our co-pending Patent Application No.

   42995/78 (Serial No. 1560999) of even date herewith.

   WHAT WE CLAIM IS:- 1. A valve for use in a pressurised fluid distribution pipe, said valve having a plastics body; plastics fluid isolation means disposed therein for rotation about a central axis; and a valve positioning handle comprising an extended fitting centrally aligned with said axis and having working surfaces thereon for rotational driving engagement by a torque applying tool; and a connecting section integrally joining said extended fitting and an end of said isolation means, said section having predetermined crosssectional dimensions in a plane perpendicular to said axis to ensure failure of said section prior to generation of forces caused by said torque applying tool being utilised to rotate said extended fitting which would be so excessive as to cause destruction or damage of the valve body or isolation means.
2. 2. The valve as set forth in Claim 1, wherein said body of said valve includes a pair of position stop means, and said handle includes a pair of position indicating tabs aligned with said respective stop means during rotation to limit rotation of said isolation means between an opened and a closed position.
3. 3. The valve as set forth in Claim 2, wherein said position indicating tabs are integrally formed, radial extensions of said connecting section.
4. 4. The valve as set forth in Claim 2 or

   3, wherein said position stop means extend axially above said position indicating tabs to protect said position indicating tabs from undesired contact with said torque applying tool during engagement thereof with said extended fitting.
5. 5. The valve as set forth in Claim 4, wherein said body of said valve is axially separated from said position indicating tabs to allow limited axial movement of said isolation means without said body making contact with said position indicating tabs,
6. 6. The valve as set forth in any one of the preceding claims, wherein said extended fitting includes a deflection formation thereon to minimize the effect of an impact force in a generally axial direction being applied to said valve positioning handle which might result in undesired failure of said connecting section.
7. 7. The valve as set forth in Claim 6, wherein said deflection formation has a plurality of facets located at the top of said extended fitting and inclined with respect to said axis.
8. 8. The valve as set forth in Claim 7, wherein said facets are aligned with said working surfaces to facilitate alignment of said torque applying tool with said working surfaces as said torque applying tool is being engaged with said extended fitting.
9. 9. The valve as set forth in any one of the preceding claims wherein the types of torque applying tool which can be used include an inverted U-shaped wrench having a pair of parallel leg planes, and a square-shaped wrench having four side planes; and said working surfaces of said extended fitting include a pair of opposed surfaces parallel with said axis and each other for engagement by parallel leg planes of said inverted U-shaped wrench. and a quadruplet of surfaces each parallel with said axis and disposed with respect to each other for engagement by said side planes of said square-shaped wrench.
10. 10. A plastics valve substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
11. 11. The combination of a plastics valve as set forth in any one of the preceding claims and a plastics pipe for pressurised fluid distribution into which said valve is connected, said cross-sectional dimensions of said connecting section ensueing failure of said section prior to generation of said forces which would be so excessive as to cause destruction or damage of said body, isolation means, or said plastics pipe.