GB2033551A - Rotary valve - Google Patents

Abstract

In a rotary ball type valve adapters 45, 46 are removably attached to a valve body 11 and normally retain a pair of annular sealing means 40, 41 against opposite sides of the ball member 18. Snap rings 68, 69 on the body and projecting into the valve chamber prevent the ball member 18 and the upstream sealing means from being blown out of the chamber by fluid pressure if the downstream adapter and its associated sealing means is removed from the body while there is fluid pressure within the valve. The rings 68, 69 may each be replaced by a plurality of pins or an integral flange formed on the valve body. <IMAGE>

Description

SPECIFICATION Rotary valve The invention relates to rotary valves.

According to one aspect of the invention, there is provided a valve comprising a body having a valve chamber, a valve plug rotatably mounted in the chamber, an adapter removably attached to one end of the body and closing one end of the chamber, a sealing means between the adapter and plug, means defining a flow path through said valve, said means including a port through the plug, a port through the sealing means, and a port through the adapter, means for rotating the plug to open and close the flow path, and abutment means on one side of the plug engageable by the plug to retain the same within the chamber when the adapter is removed from said body.

According to another aspect of the invention, there is provided a valve comprising a body having a cylindrical bore therethrough defining a valve chamber, a spherical valve plug rotatably mounted in the chamber, first and second adaptors removably attached to said body at opposite ends thereof for closing said chamber, first and second annular sealing means between the plug and a respective one of said adapter, means defining a flow path through said valve, said means comprising a port through said plug, ports through each of such sealing means, said plug having a diameter smaller than that of the cylindrical bore, first and second abutment means mounted on the body on each side of the plug extending radially inwardly of the cylindrical bore to a diameter less than that of the plug to retain the plug within the chamber in the event either adapter is removed from said body.

Ball type valves are commonly used to control flow of high pressure fluid through pipe or tubing lines, as for example in instrumentation lines for chemical processing equipment. Such valves have a ball type plug with a port therethrough that may be rotated into and out of registry with a flow path through the valve body for controlling flow through the valve. In a known form of such valve, shown in U.S. Letters Patent 3,731,904 the ball type plug is rotatably mounted in a cylindrical valve chamber of the valve body and is normally retained in its proper position within the chamber by a pair of annular sealing means that engage the plug and which in turn are held against the plug by adapters threaded to the valve body for closing the valve chamber.

However, with such valves, the plug and sealing means are slidable within the cylindrical valve chamber and if a workman removes the downstream adapter while there is fluid pressure in the upstream adapter, the fluid pressure may blow the plug and upstream adapter out from the valve chamber through the end that was opened by removal of the downstream adapter and possibly cause damage or personal injury.

The present invention, in its preferred form, prevents blow out of the valve plug and sealing means in valves of the type described above by providing abutment means mounted in the valve body mounted on each side of the plug and project.

ing into the valve chamber to a diameter less than that of the plug and sealing means so that upon removal of either adapter and its associated sealing means while there is fluid pressure in the other adapter, the abutment means will engage the plug and the upstream sealing means as they start to move outwardly and thus retain them within the valve chamber.

A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which: Figure 1 is a cross section view of the preferred valve with the parts in their normal operating position.

Figure 2 is a cross section view of the valve with the downstream and sealing means removed and showing how the abutment means of the present invention prevents the ball type valve plug and the upstream sealing means from being blown out through the open valve chamber, and with a portion of the plug further cutaway to show a bleed slot in the abutment means.

Figure 3 is a fragmentary cross section view a pin as the abutment means for retaining the plug.

Valve 10 has a body 11 with a cylindrical bore 12 therethrough that is threaded as at 13 and 14 at its opposite ends and whose central portion between the threaded ends serves as a valve chamber designated 17.

Rotatably mounted within valve chamber 17 is a ball type plug 18 whose outer surface 19 is on a radius slightly smaller than the diameter of cylindrical valve chamber 17 so that the ball plug may readily rotate within such valve chamber and is also slidable therein so that it may be inserted and removed from the valve chamber through one of the threaded ports 13,14.

The valve plug has a port 21 therethrough and also has a groove 22 for receiving a tongue 23 on a valve stem 24. Groove 22 and tongue 23 provide a driving connection whereby the ball 18 may be rotated by stem 24.

Stem 24 has a flange 26 engagable with the top of plug 18 and whose upper surface 27 is engagable by a metal washer 28 located at the bottom of a packing bore 29. Another metal washer 30 is spaced from washer 29 and between the washers is a packing ring 31 of elastomeric or other deformable material for sealing stem 24. The upper end of packing bore 29 is threaded as at 33 to receive a threaded gland 34 for compressing and retaining packing ring 31. A handle 36 is suitably attached to stem 24 by a pin or other means 37 so that the stem may be rotated by the handle.

Slidably mounted within the valve chamber 17 on each side of valve plug 18 are sealing means generally designated 40,41. Each sealing means includes a sleeve 42 slidably mounted within a corresponding recess 43, 44 of respective adapters 45,46. Each sleeve 42 has an elastomeric sealing ring 47 attached to its inner end for sealingly engaging plug 18. Mounted between a shoulder 50 on each sealing ring 42 and the inner ends 52,53 of respective adapters 45,46 are elastomeric o-rings 56,57 which seal valve chamber 17 exteriorly of plug 18 from flow path bores 59 and 60 through adapters 45, 46. Additional elastomeric sealing rings 61,62 seal the threaded joints between adapters 45,46 and body 11.

Cylindrical valve chamber 17 has a pair of grooves 65, 66 formed therein which receive wire snap rings 68,69. In the normal position of the valve parts, shown in Figure 1, the snap rings 68,69 are on opposite sides of ball plug 18 and project radially inwardly to a diameter less than that of the plug 18 and the outer diameter of sleeves 42 and are out of contact with both the plug and the sealing elements 40,41 so as not to interfere with the valving and sealing movement of these parts.

As shown in Figure 2, the snap rings 68, 69 have a radial split 70 that is of narrow width when installed.

Snap rings 68,69 as shown are of round cross section and of a single turn. Other forms of snap rings, such as square cross section and/or of more than one full turn may be used. Other forms of abutment means, such as one or more pins, as shown at 75 in Figure 3, or flanges integral with the body or rings threaded into the body bore 17 may be used. In the latter two cases it is desirable to provide a small leak path therethrough, comparable to split 70, that will not be closed when the ball is against the abutment.

When the valve is fully assembled, as shown in Figure 1, the plug adaptors 45,46 abut against the end faces 70,71 of valve body 11 and their inner ends 52, 53 compress sealing rings 56, 57 into sealing engagement with end faces 50 of sleeves 42 and press the sleeves toward ball plug 18 so that sealing rings 47 will sealingly engage the outer surface 19 of the plug. When the plug is turned to the position shown in Figure 1 a flow path is established through the valve that includes port bores 59, 60, sleeve bores 57 and bore 21 through the bore plug 18. Upon turning valve stem 24 90 by means of handle 36, valve plug 18 is also turned 90 so that bore 21 is no longer in registry with sleeve bores 57 and thus the valve plug will prevent flow of fluid through the valve.

In the event adapter 46 is downstream in the installation and is unthreaded from valve body 11 and removed from the body along with sealing element 41, if there is any fluid pressure in upstream port 59, such fluid pressure will act upon sealing element 40 and upon valve plug 18 and blow them out through valve chamber 17 and threaded bore portion 13 unless some means is provided for restraining the same. This invention provides such restraining means, preferably in the form of snap rings 68, 69, or other abutment means described herein. Thus, as shown in Figure 2 when adaptor 46 has been removed, fluid pressure in port 59 will cause the valve plug 18 and sealing element 40 to move to the right until sealing element 40 engages snap ring 69 and plug 18 engages snap ring 68 which prevents blowing out of element 40 and plug 18 through threaded port 13.

The tongue and groove connection 23,22 permits movement of the plug toward snap ring 68 without interference. When the spherical plug engages snap ring 68 it substantially seals there against so that the only escape of pressurized fluid from port 59 through port 13 is the very small amount that may leak through split 70 in snap ring 68. This bleeds down the upstream line so that eventually there is no upstream pressure to try to blow the plug out.

Likewise, if adaptor 45 is downstream and it and sealing element 40 have been removed, fluid press ure in port bore 60 of adaptor 46 will move the valve plug and sealing element 41 in the opposite direction but they will be prevented from blowing out through threaded port 14 by snap rings 68 and 69. Thus, the snap rings provide a positive safety feature to prevent the valve plug from being blown out from the valve body when either of the adapters are removed while pressure is in the valve.

Claims (12)

1. A valve comprising a body having a valve chamber, a valve plug rotatably mounted in the chamber, an adapter removably attached to one end of the body and closing one end of the chamber, a sealing means between the adapter and plug, means defining a flow path through said valve, said means including a port through the plug, a port through the sealing means, and a port through the adapter, means for rotating the plug to open and close the flow path, and abutment means on one side of the plug engageable by the plug to retain the same within the chamber when the adapter is removed from said body.

2. The valve of claim 1 in which said abutment means is out of contact with said plug when said adapter is fully assembled to said body and said sealing means engages said plug.

3. The valve of claim 1 or 2 in which said chamber is cylindrical and said plug is generally spherical and of a diameter no larger than that of the cylindrical chamber.

4. The valve of any preceding claim in which said abutment means comprises a snap ring mounted in the body and projecting into said chamber.

5. The valve of claim 1 in which said abutment means is between the plug and sealing means and normally out of contact with each.

6. The valve of any preceding claim in which the annular sealing means is slidable within said chamber and is held in sealing engagement with said plug by said adapter when the latter is fully assembled to said body.

7. The valve of claim 6 in which said valve chamber includes a cylindrical bore that is open to said one end of the body and into which the plug and sealing means may be slidably inserted from said one end when the adapter is removed from the body.

8. A valve comprising a body having a cylindrical bore therethrough defining a valve chamber, a spherical valve plug rotatably mounted in the chamber, first and second adaptors removably attached to said body at opposite ends thereof for closing said chamber, first and second annular sealing means between the plug and a respective one of said adapter, means defining a flow path through said valve, said means comprising a port through said plug, ports through each of such sealing means, said plug having a diameter smaller than that ofthe cylindrical bore, first and second abutment means mounted on the body on each side of the plug extending radially inwardly of the cylindrical bore to a diameter less than that of the plug to retain the plug within the chamber in the event either adapter is removed from said body.

9. The valve of claim 8 in which said abutment means projects radially inwardly into said bore and are out of contact with both the plug and the sealing means when the adapters are fully assembled to the body.

10. The valve of claim 8 or 9 in which said bore is internally threaded at its ends and said adapters have externally threaded portions engaged with the internal threads and the inner ends of each of said portions engage a respective one of said sealing means.

11. The valve of claim 89 or 10 in which said abutment means also project radially inwardly to a diameter less than the outermost diameter of the sealing means, and each abutment means is mounted between the plug and a respective one of said sealing means.

12. A valve substantially as hereinbefore described with reference to the accompanying drawing.