Liquid dispensing apparatus

June 22, 1937.

R. E. RISSER

LIQUID DISPENSING APPARATUS

Filed Nov. 2, 1936

2,084,597

Sheets-Sheet 1

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June 22, 1937.

R. e. risser 2,084,597

LIQUID DISPENSING APPARATUS

Filed Nov. 2, 1936 2 Sheets—Sheet 2

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Patented June 22, 1937

2,081597

UNITED STATES PATENT OFFICE

2,084,597

LIQUID DISPENSING APPARATUS Ross E. Risser, Bonham, Tex.

Application November 2, 1936, Serial No. 108,713

Claims. (Cl. 221—95)

This invention relates to new and useful improvements in liquid dispensing apparatus.

One object of the invention is to provide an improved apparatus, particularly adapted for 5 use with the usual liquid dispenser for relieving the pressure which has formed in the dispensing system due to vaporization or thermal expansion of the liquid.

An important object of the invention is to pro10 vide improved means operating at or near the highest point in a closed liquid dispensing system, whereby abnormal pressure which may develop due to vaporization or thermal expansion of the liquid in said system, is relieved; thereby 15 eliminating the possibility of such abnormal pressure emptying the lines of said system by forcing the liquid therefrom.

Another object of the invention is to provide an improved pressure relief apparatus for the 20 usual liquid dispensing system, which is arranged to remain closed during the normal operation of the dispenser and is adapted to automatically open when the pressure resulting from vaporization and also from the thermal expansion of the 25 liquid, reaches a predetermined point.

A further object of the invention is to provide an improved pressure relief apparatus, which is connected in the system of an ordinary liquid dispenser, at or near the highest point thereof, 30 said apparatus having an outlet which is so arranged that any vapor passing through the apparatus may escape to atmosphere, while any liquid which is forced through the apparatus by an abnormal pressure is conducted back into the 35 system.

A construction designed to carry out the invention will be hereinafter described, together with othei’ features of the invention.

The invention will be more readily understood Ί0 from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a view partly in vertical section ⁴³ and partly in elevation of an ordinary gasoline dispensing pump, having a relief valve, constructed in accordance with the invention connected therein,

Figure 2 is a horizontal, cross-sectional view, taken on the line 2—2 of Figure 1,

Figure 3 is an enlarged, transverse, vertical, sectional view, taken on the line 3—3 of Figure 2 and showing the side of the valve opposite that 55 shown in Figure 1,

Figure 4 is a vertical, sectional view, taken on the line 4—4 of Figure 3,

Figure 5 is an enlarged, sectional view of the valve,

Figure 6 is an enlarged, detail view of the 5 usual check and relief valve,

Figure 7 is an elevation of the upper end of another form of gasoline pump, having the invention applied thereto, and

Figure 8 is an enlarged elevation of the visi- ΐο gauge of this pump and showing the vapor relief valve connected thereto.

In the drawings, the numeral 10 designates the casing or shell of an ordinary gasoline dispenser. The shell encloses the entire pumping 15 and metering mechanism, being mounted on a suitable base ί!. The particular mechanism of the dispenser forms no part of the present invention and, therefore, is subject to variation.

For purposes of illustration, the dispenser is ₂₀shown as including the vertical line 12 which has its lower end leading from the suction pump (not shown), which draws the gasoline from the usual storage tank, while the upper end of said line is connected to the lower end of the air separator ₂5 13. The usual air eliminator 14 is mounted above the separator and has a vent tube 14' leading from its upper end, as will be explained. From the separator, the gasoline flows through the elbow (5' and upwardly through a vertical line θθ IS. From the upper end of the line 15, the gasoline is conducted by suitable elbows and pipes (6 through the usual visigauges 17 (Figure 2) and finally to a laterally extending pipe 18, which pipe has its outer end projecting through the wall 35 of the shell or casing 10. This projecting end has the usual elbow 19, to which one end of the discharge hose 20 is secured. The opposite end of the hose is provided with the usual control valve 21 and discharge nozzle 22, the nozzle be- 40 ing adapted to be inserted in the usual inclined, cylindrical nozzle boot or sleeve 23 when the hose is not in use.

A check valve 24 is connected in the vertical line 15 near the lower end thereof and this valve 45 is arranged to permit an upward flow, but not a downward flow through said line. Incorporated in the check valve 24 is a pressure relief valve 25 so that in the event that the pressure between the valve 24 and the discharge hose becomes 50 excessive, this relief valve opens to permit the gasoline in the lines thereabove to flow back to the separator.

As above described, it is obvious that the gasoline is pumped into the separator (3, through 55

2,084,597 an elbow 15', line i5, past the valve 24 which is unseated upwardly, through the elbows and pipes IS, visigauges 17, and finally through the pipe 18 to the discharge hose 28. As soon as the dispensing of the gasoline is stopped and the control valve 2i at the nozzle 22 cut off, the check valve 24 is seated to trap gasoline in the system between said valve 24 and the nozzle. This gasoline cannot escape unless the pressure becomes excessive above the pressure relief valve 35, at which time the valve is forced open and the gasoline forced back into the separator. The above parts are all of the usual construction and are, therefore, subject to variation.

It has been found that pressure is formed by vaporization due to high atmospheric temperatures and also by thermal expansion of the gasoline which is trapped in the system between the check valve 24 and discharge nozzle. This pressure is, of course, built up when the pump is not operating and the vapor rises to the highest point of the lines in which it is trapped, such point being adjacent the elbow S 8 to which the hose 20 is attached. The pressure continues to build up in the elbows and pipes (6, line !5 and hose 20. If the control valve 21 at the nozzle holds, then the pressure relief valve 25 is opened. Many times, however, the excessive pressure causes the control valve 2 J to leak.

The opening of the relief valve 25 causes the pressure to force the gasoline from the piping ί 3 and visigauges (7 downwardly through the line 15 and back to the separator 13. From the separator, the liquid is forced into the eliminator 14 and through the vent tube 14' thereof. The outer end of the tube 14' is vented to atmosphere, whereby the gasoline forced from the system is wasted, running down the exterior surface of the shell 10 and creating a fire hazard. Eventually, the pressure will entirely empty the visigauges 17 and line 15. Further, the excessive pressure against the hose 28 and control valve 2I is undesirable. Thus, it will be seen that the relief valve 25 will relieve abnormal or excessive pressure, but due to its location, is disadvantageous because it not only permits the system to be emptied of gasoline, but also permits a waste of gasoline.

For relieving the pressure of the vapor trapped between the hose 28 and check valve 24, a vapor relief valve 30 is connected in the lateral pipe 18 and is substituted for the usual relief valve 25, which is eliminated from the valve 24. The valve 30 is preferably mounted at the outer end of said pipe, being located just within the shell or casing 10. The valve includes a valve body 3' (Figure 5) which has its upper end curved upwardly at its central portion, as shown at 3!', whereby this portion is in a plane above the pipe 18 and elbow 19. A collar 32 is formed at the lower end of the valve and this collar is internally screw-threaded. An elongate sleeve 33 is inserted through the collar to extend vertically within the valve body, the lower portion 33' of said sleeve being externally threaded so as to screw into the collar 32.

The upper end of the sleeve 33 is closed except for a reduced axial port or opening 34. A conical valve member 35 is located within the sleeve and is adapted to engage in the opening 34 to control the same. The member is normally held in its seated position by a coiled spring 30 which is mounted within the bore of the sleeve, being confined between the lower end of the member 35 and a plug 37 which is threaded into the lower end of the bore of said sleeve. The plug is formed with an axial bore or opening 33, which extends entirely therethrough, whereby communication between the bore of the sleeve above the plug and that portion of the bore of 5 said sleeve below the plug, is established.

The extreme lower end of the sleeve 33 is formed with an enlarged head 39 provided with internal screw threads for receiving one end of an elbow ¢8 (Figure 3). The other end of the 10 elbow is connected to the upper end of a vertical conductor 4 ί, which has its lower end connected to the upper end of and depending downwardly through the vertical ’eg of a T connection 42 (Figure 4). The opposite end of said leg is con- 15 nected to the upper end of the vent tube 14' of the air eliminator, and the conductor 4! is of sufficient length to extend axially within the upper portion of the tube 14'. It is noted that both the tube and T have a greater diameter 20 than the conductor, as clearly shown in Figure 4.

The lateral leg 42' of the T is connected to an opening 43 which is provided in the side of the nozzle boot or sleeve 23, which boot is open to the atmosphere. A suitable screen 44 covers 25 the opening 43 to prevent dirt and other extraneous matter, entering the T 42 and tube 14'. With this arrangement, it will be seen that air rising from the air eliminator 14 may pass through the tube !4', upwardly around the lower 30 end of the conductor 41 and outwardly to atmosphere from the T connection 42 through the boot or sleeve 23. Vapor passing downwardly through the conductor 4i is released from the lower end thereof into the upper end of the tube 35 !4', from which it escapes to the atmosphere through the T 42. and boot 23. Any gasoline which may escape through the conductor will, of course, drop downwardly into the eliminator i 4, from where it can be conducted by a return 40 line 45 (Figure 1) back to the suction pump (not shown).

During the normal operation of the dispensing pump, the valve member 34 remains in its seated position, because the pressure of the coiled 45 spring 3S is sufficient to· resist this pump pressure. Therefore, the valve 39 is inoperative during the normal operation of the pump and does not in any way interfere with the dispensing of the gasoline, said gasoline passing around the 50 sleeve 33 and out through the hose 28. When the pump is not operating, the nozzle 22 is placed within the nozzle boot or sleeve 23, the outer end of the hose being supported by the usual bracket 16' provided for this purpose. At this 55 time, as has been explained, the control valve 21 at the nozzle and the check valve 24, are closed, Whereby gasoline is trapped therebetween.

When the atmospheric temperature is sufficiently high, vaporization of the gasoline occurs ⁶⁰and the vapor will, of course, rise to the highest point in the lines wherein said gasoline is trapped. This highest point is the upwardly extended top of the valve body 31 adjacent the valve member 35. The vaporization, together ⁶³with the thermal expansion of the gasoline, will build up a pressure in the lines between the nozzle valve 2! and check valve 24, and when a predetermined pressure in the valve body 3! is reached, the valve member 35 is moved down- ‘ wardly under tension of the spring 3S, whereby the axial opening 34 in the sleeve 33 is uncovered and the pressure relieved. Any vapor which may have formed is permitted to escape down- 75

2,084,597 wardly through the bore sleeve 33, port 38 in the plug 37, and into the conductor 41. As has been explained, the vapor released from the lower open end of the conductor rises into· the 5 T 42, from where it escapes to atmosphere through the screened opening 43 and boot 42. Any gasoline which is expelled through the sleeve 33 merely falls from the conductor 41 into the vent tube 14' and is thereby conducted to the 10 eliminator 14, and then through the return 45 to the suction pump (not shown).

Therefore, it will be seen that the vapor is taken from the system at its point of accumulation and an abnormal pressure, due either to Irf vaporization or thermal expansion of the gasoline, which otherwise would entirely empty the piping 16, visigauges 17, and line 15, and result in a waste of gasoline, is prevented. It is noted that although it is preferable to mount the pres20 sure relief valve at the highest point in that portion of the system wherein gasoline is trapped when the pump is not operating, it is not absolutely essential. So long as said valve is located sufficiently close to prevent forcing the gasoline ²⁵ from the lines of the system, the purposes of the invention are accomplished.

In Figures 1 to 6, the invention has been shown as applied to an ordinary dispenser including the usual air eliminator and separator. Many dis³⁰ pensers do not have these parts and, obviously, they form no· part of the invention per se. If an eliminator is not employed, then the conductor 41 could have its lower end entering any suitable tube, which would conduct the gasoline ³⁵ entering the same back to the suction pump or the original source of supply.

The dispenser shown in Figures 1 to 6 is one wherein the visigauges 17 are located in the wall of the shell 10. In many instances only a single ⁴θ exterior visigauge is provided. Such a structure is shown in Figures 7 and 8, wherein an exterior visigauge 50 is; substituted for the elbow 19, which is secured to the extending end of the lateral pipe 18. With this arrangement, the up⁴⁵ per end of the visigauge 50 is the highest point of that portion of the system wherein gasoline is trapped, and, therefore, the valve 30 is preferably mounted thereabove. In this instance, the structure of the valve is exactly the same and ⁵⁰ has one end connected by an elbow 51 with the top of the gauge. The opposite end of the- valve is closed by a plug 52, while the conductor 41 leads from the lower end of the valve body, as in the other form. The operation of the valve is ⁵⁵ exactly the same as hereinbefore described, the valve 30 opening when the pressure reaches a predetermined point.