MXPA05007398A - Apparatus for performing blocking and counterpressure tests in vapour recovery systems. - Google Patents

Abstract

The present invention refers to an apparatus for performing blocking and counterpressure tests in vapour recovery systems of service stations; the improvements of the present apparatus over prior state-of-the-art apparatuses comprise its capability to be used in any Vapour Recovery System regardless of the distance between the dispensing line thereof and a Storage tank. The inventive apparatus includes electronic fittings and design improvements, and has no distance or diameter limitations in pipe lines, the invention being also useful for facilities handling vapour or gas flows.

Description

APPARATUS FOR BLOCKING AND COUNTERPRESSION TESTS IN VAPOR RECOVERY SYSTEMS DESCRIPTION TECHNICAL FIELD OF THE INVENTION The present invention relates to an apparatus for performing blocking and back pressure tests in petrol vapor recovery systems at service stations for motor vehicle users.

BACKGROUND OF THE INVENTION The Vapor Recovery Systems (SRV's) in the Service Stations have been installed in the United States for more than 20 years, but in Mexico they are relatively recent. On January 8, 1992, the Presidential Agreement for the creation of the Commission for the Prevention and Control of Environmental Pollution in the Metropolitan Zone of the Valley of Mexico was published in the Official Gazette of the Federation, under the requirement of protection environmental with maximum efficiency. The fundamental purpose of the Metropolitan Commission is to define and coordinate the policies, programs and projects in the matter, as well as to verify the execution of the actions that the dependencies and entities of the public administration should undertake. During the year of 1995, these systems began to be installed with formality in the Metropolitan Area of Mexico City. However, the equipment installed in Mexico incorporates a series of modifications and improvements. It is also worth mentioning that, in that year, the "Rules of Operation to Install Vapor Recovery Systems in the Gas Stations of the Valley of Mexico" were established, with the support of the "Specifications for Project and Construction of Service Stations of PEMEX- 1994 reference. " Therefore, under the supervision of the Mexican Petroleum Institute (IMP), companies wishing to obtain the authorization and registration to supply and install SRVs, must comply with the requirements established in the published call SEEM-DE / SRV-1994-01 in the Official Gazette of the Federation of June 2, 1994. It should be mentioned that the IMP has evaluated the service stations before, during and after the completion of the installation works of the SRVs in order that the corresponding authorities of the Metropolitan Area of the Valley of Mexico issue the authorization to the operation of the SRV's, once all the corresponding tests have been approved. In terms of the state of the art the applicant knows that the Agency of California Environmental Protection implemented a procedure specified in the California Air Resources Board (CARB) test for vapor recovery (TP-201.4) dated July 3, 2002, which is used to verify dynamic limits applicable of the back pressure imposed before any system of vapor recovery of gasoline. The methodologies in this procedure are applicable for proof of certification and compliance. This method is only for dynamic tests, which does not give safe measurements, there are problems regarding guns, valves, connections or attachments in the vapor recovery system. Additionally, it is worth mentioning that it only has two measurement ranges. The present invention provides an apparatus that presents considerable differences with respect to the technology previously exposed, since it has equipment for flow measurement, pressure measurement and regulation of flow and pressure, which makes it possible to use it for any underground pipeline. transport vapors or gases, and has three ranges of measurement. Also, it has no restrictions, since, the method is for dynamic tests (dry) and blocking (wet), which gives safe measurements, not having problems in terms of guns, valves, connections or attachments that are installed in the Vapor recovery system according to any system need.

SPECIFICATION OF THE INVENTION Therefore, an object of the present invention is to provide a novel apparatus that verifies, by means of non-destructive testing, that the pipe or main pipes of the Vapor Recovery System in the Stations of Service: (1) No counter-present; and (2) Do not present obstructions. Another object of the present invention is to use it in all the SRV's installed in Service Stations for (1) Phase I Vapor Recovery Systems where the recovery of gasoline vapors is carried out from the tank truck when the product is unloaded into the product tank; and (2) Phase II Vapor Recovery Systems where the recovery of gasoline vapors is carried out from the product tank when the product is loaded into the vehicle tank.

BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION The figures that accompany the present invention are described below to have a better understanding of the objectives, without limiting their scope. Figure 1 shows the representation of the Installation of Vapor Recovery Systems in a service station at a gas station. Figure 2 shows the installation of the invention in the Vapor Return Line. In Figure 3 a diagram representing the instruments and connections of the present invention is shown.

DETAILED DESCRIPTION OF THE INVENTION The present invention is located in a Vapor Recovery System (SVR's), and consists of a flowmeter coupled to a simulator tube of the car to a bullet in which three pressure gauges are connected in series in one series of needle and gate valves and the main objective is the simulation of constant flows to verify the slope of the pipes and can be used for any underground pipeline that transports vapors or gases, and has three ranges of measurement. The equipment has a series of valves for the safety of the equipment such as pressure gauges for the performance of tightness tests on the same equipment. In order to show the main features of the apparatus of the present invention, reference will now be made to the accompanying figures. As shown in Figure 1, Gasoline Steam Recovery Systems in the Service Stations have been classified into two concepts: I) Phase I Vapor Recovery Systems, where the recovery of gasoline vapors is done from the tank truck When the product is unloaded into the product tank: the flow of the product to be unloaded (A) from the tank truck (G), is controlled through the discharge valve (C) to the storage tank (D). In order not to cause backpressure during filling, there is a vapor return pipe (E), which helps return the product that volatilizes to the tank truck (G). When blocking the valve (C), it must be airtight. The vent pipe (B) must meet the following requirements: (i) be airtight; (ii) have a minimum slope of 1%; and (iii) no obstruction. II) Phase II Vapor Recovery Systems, where the recovery of gasoline vapors is carried out from the product tank when the product is loaded into the tank of the motor vehicle: the flow of the product to be charged (G) is controlled through the pistol load (I) from the dispensary (H) to the vehicle tank (J). In order not to send the volatile vapors of the product to the atmosphere during filling, there is a vapor return pipe (K), which helps to return the product that is volatilized from the tank of the vehicle. The dispensing vapor return pipe (K) must meet the following installation requirements: (i) Specified diameter of 1 to 4 inches; (ii) Type of material; (iii) A minimum slope of 1% towards the product tanks; (iv) Do not present obstructions; and (v) Be airtight. Any of the installation features, mentioned above, that does not comply with the gas vapor return line causes the Recovery System not to work properly, and all gasoline vapors would be emitted into the atmosphere. The apparatus of the present invention verifies, by means of non-destructive tests, that the pipeline or the main pipes of the Vapor Recovery System in the Service Stations of a gas station: a) Does not present a counter-dependent; and b) Do not present obstructions. In Figure 2, the best way to use the equipment of the present patent application is illustrated, wherein: (A) represents the module of the apparatus of the present invention; (B) represents the vent pipe; (C) the dispensary of the product; (D) the vapor return line of the product; (E) the line for filling the product to the vehicle; and (F) the product storage tank. Although in Figure 2, only the application of the present invention for Phase II Vapor Recovery Systems is illustrated, it is not limiting to it, and it also applies to Phase I Vapor Recovery Systems. 3, the apparatus is constituted of a needle valve (02) where the gas flow is injected and is coupled to a rotameter (01) and controlled with a needle valve (03). The above accessories are coupled with flow meter (04) in which the injected gas flow is measured, and is regulated by gate valve (05), where, the gas flow is supplied in the vapor recovery line by the simulator tube of the flow auto (06). The gas flows supplied in the vapor recovery line generate a backpressure in the line which pass through the bale pressure equalization (014), and the pressure generated is controlled by the gate valves (08, 010, 012) and these allow that according to the pressure range of use for its measurement with range of dial gauges (09) with range of 0-10 pca (inches of water column) and (013) with range of 0-30 pca or with the inclined manometer (011) with range of 0-1 pca The gate valves (015) installed in the bala equalization pressure (014), are used when a pressure greater than the range of the dial gauges (09) with range of 0-10 pca and (013) with range of 0 is generated -30 pca of range of or with the inclined manometer (011) with range of 0-1 pca The gate valves (015) and the dial gauge (016) with a range of 10 psi; They are used when a leak test is performed at 5 psi (pounds per square inch).

EXAMPLES In order to illustrate in a better way the application of the apparatus of the present invention, examples that support the above described are presented below, which does not limit the scope of what is claimed here.

EXAMPLE 1 As seen in this example, in the following table 1, the results obtained in the back pressure test are recorded. These tests last for 1 minute for each nitrogen flow (19, 29 and 39 liters per minute), and three nitrogen streams are used for this test. The pressure values are indicated by the pressure gauges that are installed in our innovation described in figure 3; after recording the minimum and maximum pressure value, the pressure difference is calculated, this pressure difference will indicate in what condition the vapor return line is located.

Table 1. Results of the back pressure test at a service station (gasoline) * LPM = liters per minute ** p.c.a = inches of water column As can be seen in the table, during the application of the apparatus of the present invention we can say that for this case, the return pipe: (i) is hermetic; (ii) has a minimum slope of 1%; and (iii) there is no obstruction.

EXAMPLE 2 In this test, the same procedure used in Example 1 is used, but just before the nitrogen flow is injected, gasoline is introduced into the vapor return line to simulate a blocking test. The results for this example are shown in table 2.

Table 2. Results of the blocking test at a gas station (gas station).

* LPM = liters per minute ** pca = inches of water column As can be seen in table 2, during the application of the apparatus of the present invention, we can say that for this case, the line: (i) is not hermetic; (ii) has no minimum slope of 1%; and (iii) presents obstruction, by virtue of the pressure values (p.c.a) or the pressure difference are greater than those shown in table 1.

Claims (1)

1. NOVELTY OF THE INVENTION It is claimed: An apparatus for blocking and back pressure tests in vapor recovery systems, characterized in that it consists of: (a) a needle valve, where the gas flow, such as nitrogen, is injected and coupled to a rotameter where it is controls flow with needle valve; (b) the accessories of part (a) are connected to a flow meter, which measures the gas injected, in a range of 15 to 45 liters per minute; (c) a gate valve is then coupled, in which the gas flow of the vapor recovery line of the car tube simulator is supplied; (d) a bullet pressure equalization, in which the gas flows supplied in the vapor recovery line are equalized; (e) gate valves for pressure control connected to dial gauges with measurement intervals of 0-10 inches of water column (p.c.a.), or 0-30 p.c.a .; or with an inclined manometer of 0-1 p.c.a; (f) gate valves installed parallel to the bullet pressure equalization, used when a pressure greater than the range of the pressure gauges mentioned in subsection (e) is generated. An apparatus in accordance with clause 1, characterized in that the gate valves indicated in subsection (e) are also used when a leak test is performed at 5 psi (pounds per square inch). An apparatus in accordance with clauses 1 and 2, which is used for Phase I or II Vapor Recovery Systems.