Valve having integrity assurance means

#Butterfly type valves have long been known and are commonly used in industry. With a butterfly or any other type valve it is frequently desirable to expeditiously determine the integrity of the valve when it is in the closed position, that is, to determine as a certainty whether or not the valve is permitting leakage of fluid or gases past it.

#In many industrial applications integrity of valve closure is assured by placing two valves in series. The valve closure members may be coupled together for simultaneous action. When the coupled valves are closed a line between the valves can then be tapped and by measuring pressure or otherwise it can be determined as a certainty that no fluid flow is taking place past the valves.

#The use of series valves is an expensive procedure. Not only does it double the valve cost to provide this leakproof assurance, but the coupling of the valve for simultaneous action is an additional expense.

#FIG. 1 is an end view of a butterfly valve embodying this invention, the valve being shown in the fully opened position.

#FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1 but showing the valve in the closed position.

#FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2.

#A valve having integrity assurance means including a valve body having a flow passageway therethrough, a disc mounted in the flow passageway, means extending through and externally of the body to controllably position the disc so that in one position it is open to permit flow of fluid through the valve to either side of the disc and in the other position it contacts the valve body around the full circumferential periphery to close against fluid flow, the disc having spaced apart parallel circumferential sealing means around the periphery thereof engaging the valve body to provide two separate spaced apart sealing engagements with the valve body, and the body having a small diameter test opening extending externally of the valve and communicating with the area between the sealing contacts when the disc is in the fully closed position providing means to indicate that the valve is not leaking.

#Referring to the drawings and first to FIGS. 1, 2 and 3, a butterfly valve embodying the principles of this invention is illustrated. The valve includes a body 10 usually made of metal, the body having a flow passageway 12 therethrough. Integrally formed with the body is a top stem housing 14 and a lower stem housing 16.

#Positioned in the valve flow passageway 12 is an elastomeric seat member 18. Rotatably positioned within the seat member 18 is a valve disc 20 having a circumferential sealing surface 22. Positioned on the sealing surface 22 is a first increased diameter circumferential sealing ridge 24 and a second, spaced apart, paralleled, increased diameter circumferential sealing ridge 26. The spaced apart sealing ridges 24 and 26 provide a circumferential valley 28 therebetween.