US1243592A - Pressure and vacuum relief valve. - Google Patents

Description

D. CRAIG. PRESSURE AND VACUUM RELIEF VALVE.

APPLICATION FILED JULY 13. I914- Patented Oct. 16,1917.

r C W p 24, WZ'Z776J886. F 2

DAVID CRAIG, OF PEABODY, MASSACHUSETTS.

PRESSURE AND VACUUM RELIEF VALVE.

Specification of Letters Patent.

Patented Oct. 16, 191:1.

Application filed July 13, 1914. Serial No. 850,810.

To all whom it may concern:

Be it known that 1, DAVID CRAIG, a citizen of the United States, and resident of Peabody, county of Essex, Commonwealth of Massachusetts, have invented an Improvement in Pressure and Vacuum Relief Valves, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts in each of the several views.

This invention relates to a relief valve device adapted for use with fluid containers and pressure systems, and is particularly, though not exclusively, designed for domes tic boiler installations. A prime object of the invention is to provide a simple, compact, unitary valve device adapted to relieve the boiler and system of eiicessive or dangerous pressure, and also to protect and relieve the boiler from crushing or crumpling in due to vacuum or unduly diminishing pressure. To these ends in the preferred embodiment shown, I provide a valve with provision for holding it to its seat with variable predetermined spring pressure and form said valve so as to serve also as a valve seat member for another valve adapted to control flow of fluid in the opposite direction. The above and other objects and features of the invention will be better understood from the following detailed description taken in connection with the accompanying drawings and will be thereafter pointed out inthe appended claim.

Referring to the drawings:

Figure 1 is an elevation showing my improved device applied to a pipe connection that may communicate with a boiler; and

Fig. 2 is a central vertical section through my improved valve, the central smaller valve and the spring being shown in elevation.

A barrel housing is indicated at 10 with a threaded nipple 11 at one end to engage with a pipe connection such as one branch 12 of a T, while the other end of the barrel has a long threaded nipple 13 to which is fitted an adjustable cap 14. The passage through the barrel is reduced at one end, shown as through the nipple 11 as seen at 15 and where this reduced portion begins it is beveled off to form a valve seat 16 to which is fitted a plug valve 17 This valve is yieldingly pressed to its seat with a predetermined variable pressure by a coil spring 18 having backing against the cap 14. Thus by adjusting said cap the tension of the spring may be varied and hence the point at which the valve 17 will open to relieve excess pressure can be varied and set as required. The valve 17 has a reduced neck 19 extending through the reduced passage 15 with clearance and a central passage 20 extends through this valve and its neck. This passage is controlled by a valve 21 fitted to a seat 22 on the end of the neck 19 and equipped with a long stem 23 extending through the passage 20 with clearance and as shown most of the way through the barrel 10; thus serving to guide and steady the action of the valve 21. The cap 14 is provided with a port 24 to permit passage of the fluid in either direction. In practice the active face of valve 21 is preferably made of lead and as the valve 17 with its neck 19 are usually of brass, there is no likelihood or danger of the cementing or stickin of the valve to its seat. It is also to be noted that the neck 19 of valve 17 and the valve 21 thereon extend up some little distance above the end of the nipple 11. The branch 12 of the T connection is also made relatively short as shown and in this way the valve 21 and its seat 22 extend up into the current of flowing water so that they are kept clean and free from sediment.

Thus the valve 17 is adapted to guard the system from excess pressure by proper adjustment of the cap 14 according to the conditions of service while the valve 21 will at once open freely as soon as the pressure in the system drops materially below atmospheric pressure relieving the boiler from danger of buckling or crumpling in from partial vacuum. I am aware that the invention can be embodied in other specific forms without departing from the spirit of the invention and I therefore refer to the .appended claim rather than to the foregoing description to indicate the scope of the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

A combined pressure and vacuum relief valve, comprising a barrel housing having a reduced portion formed with an internal tapering seat at one end portion thereof and externally threaded at the other end thereof, a cap fitted to the last named end of said housing with a central hole therethrough, plug valve to close the passage therethrough, a plug valve having a larger inner end having an elongated stem extending through 15 oosely fitting the interior of said housing the passage of said plug valve, the end of With a smaller outer end projecting outward said housing to Which said plug valve is 5 a substantial distance beyond the end or" said fitted being externally threaded for fitting housing, and With an intermediate conical to a pipe connection. portion constituting a valve to fit said taper- In testimony whereof, l? have signed my 20 ing seat in the housing, a spring reacting name to this specification, in the presence between said end cap of said housing and of two subscribing Witnesses.

.10 thelargenend of said plug valve, said plug DAV 1D CRAIG.

valve havlnga central lengthwise passage Witnesses therethrough, and a valve fitting the pro C. L. ROGERS,

jecting end or" the smaller portion of said Louise A. JORDAN.

Images