US2112641A - Safety vent valve - Google Patents

Description

March 29, 1938. A W WHEATQN 2,112,641

SAFETY VENT VALVE v Filed sept. 25, 19:56 2 sheets-sheet 1 v i 35 343 f /30 3%* f3 INVENTOR.

ATTORNEY.

March 29, 1938.

A. W. WHEATON SAFETY Filed Sept. 25, 1936 VENT VALVE 2 Sheets-Sheet 2' ATTORNEY.

Patented Mar. 29, 1938 UNETED STATES man SAFETY VENT VALVE Application September 25, 1936, Serial No. 102,486

3 Claims.

This invention relates to improvements in valves., and the invention has reference, more particularly, to a unitary combined safety and vent valve for tanks utilized to store inflammable e liquids, such as gasoline, kerosene or other more or less volatile and inflammable liquids.

This invention has for an object to provide in one unit a combined vent and safety valve which operates to normally close communication between the interior of a tank, in connection with which it is used, and the atmosphere, thus reducing tendency to evaporation of the tank content and loss of volatile gases, while nevertheless having an egress vent operative to discharge air from the tank interior as displaced by liquid entering the same during filling operations; an ingress vent operative to admit air into the tank to replace liquid withdrawn therefrom; and a safety valve arrangement operative to yield to abnormal 2;) and excessive internal tank pressure, asis likely to occur in the event of fire in the vicinity of the tank accompanied by excessive evaporation of the tank content, said safety valve arrangement providing a maximum area of free opening. The novel com- :i bined vent and safety valve therefore provides for the maintenance of suiiicient internal pressure to reduce levaporation losses to a minimum, while nevertheless providing a maximum discharge safety valve opening calculated to afford adequate 30 protection and safety as required by law.

The invention has for another object to pro-vide in the combined vent and safety valve a novel arrangement detachable flame arrester operative to protect all vent openings, which can be removed for inspection.

Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the 40 5211116.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which:

Fig. l is a Vertical cross section through the center of the valve in its normal closed condition; Fig. 2 is in part a plan View and in part a hori- Zontal sectional view of the valve; Fig. 3 is a view, similar to that of Fig. 1, but showing the operation of the egress vent and its valve means; Fig. 4 is a similar view showing the operation of the ingress vent and its valve means; and Fig. 5 is also a similar view showing the operation of the device as a safety valve. Fig. 6 is a fragmentary sectional view showing a modified cover stop means.

Similar characters of reference are employed in the above described views, to indicate corref spending parts.

Referring to the drawings, the reference character (i indicates the valve body, the same com prising, preferably, a cylindrical shelll or casing having a bottom wall l. Integral with and extending downwardly from said bottom wall l, and in axial alignmentwith said shell or casing, is a tubular neck 8, the lower portion of which is externally screw-threaded, as at 9, whereby said neck Vmay be screwed into a tank wall opening T, to thus operatively attach the valve tothe tank to be served thereby.

Provided in the bottom wall l of said shell or casing is an annular row of ingress vent openings IIJ. Vertically movable within the interior o-f said shell or casing is an annular ingress valve member iI which seats by gravity upon the inner side of said bottom wallv l so as to normally close said ingress vent openings Il). To guide the movements of said ingress valve member II Without undue friction, a plurality of vertical guide ribs I2 are formed upon and spaced around the inner sides of the shell or casing wall.

Cooperative with the upper end of said shell or casing Ii is a cover member i3, provided around its periphery with a depending annular skirt ilange ill. The diameter of said cover member I3 including its skirt ange I4 exceeds the diameter of the shell or casing I5, so as to provide an annular vent space i5 between the free margin of said skirt flange and the sides of said shell or casing. rIhe cover member thus formed is substantially in the shape of a downwardly open dome, which arches over the upper end of said shell or casing 6. Said cover member is engaged with the shell or casing by a hinge connection. This hinge connection comprises a pair of spaced hinge ears I5 which project exteriorly from the side of said shell or casing 6, with which cooperate a pair of hinge ears Il which project interiorly from the skirt flange I4 of the cover member, a

pintle or hinge pin I8 being engaged through said f adapted to cooperate with the seating ring I9 to close the safety valve port 20. 'I'his means comprises an annular wall 22 approximating in diameter that of the shell or casing 5. The wall 22 is secured to and within the cover member I3, as by bolts 23, so as to depend from the inner or under side thereof toward and in alignment with said shell or casing 6, thus defining a. chamber 24 closed at its lower end by a bottom portion 25 which constitutes a safety valve member. Formed on the underside of said bottom portion 25 is an annular seating boss 26 which cooperatesy with the seating boss 2| of seating ring I9. When the cover member I3 is' swung down to closed position, said bottom portion or safety valve member 25 is disposed over and in'closing relation to said safety valve port 20.

Centrally disposed and formed in said bottom portion or safety valve member 25 is' an egress vent port 21, the margin of which is provided with a chamferedvalve seat 28. Normally engaged by gravity on said seat 28, in closing relation to said egress vent port 21, is an egress valve member 29. This valve member 29 is preferably provided with an upwardly extending stem 30, the upper free end of which is slidably guided in the interior 3I of a vertical guiderboss 32 with which the cover'member I3 is provided. Formed in 4said annular wall 22 are egress openings 33 affording communication between the interior of the chamber 24 and the vent space I5 between cover member I3 and the body shell or casing 6. The egress valve member 29 may, by the addition of suitable perforate weights 34 thereto (which are engaged over the stem 30), be arranged to withstand desired predetermined pressure within the tankbut yield to pressure in excess of said predetermined pressure.

In order to prevent unauthorized openingof cover member I3, while nevertheless permitting suflicient opening movement thereof to effect the safety valve functioning of the device in the manner subsequently described, a slotted hasp 35 is pivotally connected to a fulcrum ear 38 which projects exteriorly from the shell or casing 6 at a point diametrically opposite the location of the cover member hinge connection. Cover member I3 is provided, at a point opposite its hinged side, with an outwardly projecting and somewhat downwardly inclined tongue 31 adapted to extend through the slotway of said hasp 35. Said tongue is provided, adjacent to its extremity, with an opening or eye 38, through which may be engaged a pad-lock 39, the latter being effective to prevent withdrawal of the tongue 31 from slotted hasp 35. In order to limit the manually actuated opening movement of cover member I3 in such manner that it cannot be inadvertently left standing open, hinge ears I6 are provided with stop lugs 48, which are engageable by the cover member periphery to limit the opening movement of the cover member to less than ninety degrees from horizontal, whereby when the hand is released therefrom, the same will immediately drop back to normal closed relation to shell or casing 6.

The device is provided with flame arrester means so located and arranged as to be inside all the valve ports thereof. This flame arrester comprises one or more mesh screen members 4I. Said screen members 4I are preferably of cupshape, and are inserted within and across the passage of the neck portion 8 leading from the shell or casing interior into the interior of a tank to which the device is operatively connected. Said screen members 4I are attached to and depend from annular supporting rings or flanges 42 which bound their peripheries. If more than one screen member is employed, the same are nested together (as shown in Fig. 1), and when inserted in said neck portion 8, the rings or flanges 42 rest upon the shoulder 43 formed at the junction of said neck portion and the shell or casing 6, thus disposing the screen members within and across the passage of said neck portion. A handle strap 44 may be provided, whereby the screen members may be manipulated when inserting or removing the same from the device. When cover member I3 is fully opened, the screen members may be withdrawn and removed from the device for inspection, repair or replacement.

When the vent valve is operatively connected With a storage tank, the same functions as follows: l

The cover member I3 is closed with its tongue 31 engaged through the slot of hasp 35, and secured against withdrawal therefrom by pad-lock 39. When the cover member is thus closed, safety Valve member 25 seals the safety valve port 29, the weight of the cover member and associated parts being sufficient to hold the safety valve member closed against all but abnormally high internal tank pressures. If desired, resistance to such internal pressure may be increased or governed to a desired degree by adding weights (not shown) to said cover member, such e. g. as perforate weights engageable over the exteriorly projecting portion of boss 32. If, under these conditions, liquid is delivered into the tank, the air displaced by the entering liquid will cause the egress vent valve 29 to lift, as shown in Fig. 3, whereupon such displaced air may escape through the egress valve port 21, chamber 24, egress openings 33, and thence to the atmosphere through vent space I between the outer margins of the cover member I3 and shell or casing 6.

In the event of condensation of vapors within the tank tending to reduce pressure therein below atmospheric pressure, ingress valve member lI will lift, thereby opening ingress vent openings Il), whereby compensating air may enter the tank interior, as indicated in Fig. 4 of the drawings.

In the event of the production of abnormal pressure within the tank interior from any cause, greater than can normally be relieved by the egress vent port and its controlling valve, a maximum opening of the device to the full egress capacity of the relatively large safety valve port 28 is available. Upon the occurrence of a sudden and abnormal rise of pressure within the tank, the same is effective upon the cover member structure as a Whole and the same will swing upward about its hinge connection with shell or casing I within the limit of movement permitted by the cooperating slotted hasp 35 and tongue 31. Such movement of the cover member removes the safety valve member 25 from seat 25, thus opening the maximum capacity safety valve port 20, as shown in Fig. 5. In valves of average size the safety valve port is six inches in diameter, so that it will be obvious that the same possesses adequate capacity to assure a rapid dissipation of abnormally high and suddenly rising internal pressure.

In connection with the above described construction I have referred to the pivoted slotted hasp 35 and cooperating tongue 31 as one form of means suitable for limiting the upswing of the cover member structure as a Whole, when the latter is moved by abnormal pressure withv connection between the cover structure and the shell or casing' 6. In this modified arrangement, slotted hinge ears I6 are provided to project from the shell or casing E for cooperation with hinge ears il' connected with the skirt flange I4 of the cover member, the latter ears carrying a pintle or hinge pin I8 which is journaled in said slotted hinge ears I6. Projecting from the hinge ears i6 are downwardly stepped stop lugs fill'. Integral with and projecting externally from said skirt iiange i4 of the cover member is a lug 45, having, adjacent to its lower end, a perforation 45'. Pivotally suspended from said lug 45 are stop-tongues 46, which, in their down-swung positions, have their free ends 41 in spaced opposition to said stop lugs 40. Said stop-tongues 46 are normally maintained in such relation to the stop lugs d' by engaging a padlock 48 or the like through the perforation of said lug 45. When the stop tongues are so disposed, the cover member structure may swing upward about its hinge connection for a limited distance until the movement is arrested by abutment of the stop tongues 46 upon the stop lugs 40', whereby the cover member structure opens sufficiently relative to the safety valve port 20 to permit of the desired maximum venting effect. If it is desired to swing the cover member structure to full open position, pad-lock .48 is removed and stop tongues 46 are out-swung to clear the stop lugs 40'.

From the above it will be apparent that this invention provides a very efficient and yet simplev and consequently comparatively low cost Vent valve capable of serving storage tanks under the various conditions requiring automatic communication between its interior and the atmosphere.

It will be understood that various changes may be made in the above described constructions, and many apparently widely different embodiments of this invention may be made without departing from the scope thereof as defined by the following claims. It is therefore intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

1. A safety vent valve comprising a main casing having a downwardly extending tubular neck of reduced diameter for communicating connection with a tank to be served, said casing having, in its bottom outwardly of said neck, yieldable ingress vent means, means at the upper end of said casing to provide a maximum capacity safety valve port, .a freely movable annularly open cover member movably connected with said casing to extend over its upper end, safety valve port closing means carried by and within said cover member, said closing means having yieldable egress vent means aligned with said safety valve port and of substantially smaller area than the latter, said egress vent means being adapted to communicate with the .annularly open portion of said cover member and being responsive to normal tank pressure uctuation, and releasable means to limit opening movement of said cover member by which the closing means is carried into open relation to said safety valve port under sudden abnormal tank pressure conditions.

2. A safety vent valve comprising a main casing having a downwardly extending neck f reduced diameter for communicating connection with a tank to be served, said casing having, in its bottom outwardly of said neck, yieldable ingress vent means, means at the upper end of said casing to provide a maximum capacity safety valve port, an annularly open cover member cooperative with the upper end of said casing, safety Valve port closing means carried by said cover member, said closing means having yieldable egress vent means aligned with said safety valve port and adapted to communicate with the annularly open portion of said cover member, a hinge connection between said cover member and main casing, a slotted hasp pivotally connected with said casing at a point diametrically opposite said hinge connection, and said cover member having a perforate tongue to engage through said slotted hasp and adapted to receive lock means to prevent manual opening of said cover member, movement of said tongue along said slotted hasp permitting limited opening movement of said cover member sufficient to carry the safety valve port closing means thereof to open relation under sudden abnormal tank pressure conditions.

3. A safety vent valve comprising a main casing having a downwardly extending neck of reduced diameter for communicating connection with a tank to be served, said casing having, in its bottom outwardly of said neck, yieldable ingress vent means, means at the upper end of said casing to provide a maximum capacity safety valve port, an annularly open cover member cooperative with the upper end of said casing, safety valve port closing means carried by said cover member, said closing means having yieldable egress vent means aligned with said safety valve port and adapted to communicate with the annularly open portion of said cover member, .a hinge connection between said cover member and main casing, a slotted hasp pivotally connected with said casing at a point diametrically opposite said hinge connection, said cover member having a perforate tongue to engage through said slotted hasp and adapted to receive lock means to prevent manual opening of said cover member, movement of said tongue along said slotted hasp permitting limited opening movement of said cover member sumcient to carry the safety valve port closing means thereof to open relation under sudden abnormal tank pressure conditions, and said hinge connection including stop means whereby manually attained opening movement of said cover is so limited as to render the same self-closing when the hand is removed therefrom.

ABRAM W. WHEATON.

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