1、 Stage II Vapor Recovery System Operations however, theInstitute makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or m
2、unicipal regulation with which thispublication may conict.Suggested revisions are invited and should be submitted to the standardization manager,American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.iiiCONTENTSPage1 EXECUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . .
3、 . . . . . . . . . . . . . . . . . . . . . . . 12 STAGE II PROGRAM BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 STAGE II SURVEY ASSUMPTIONS & APPROACH . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Survey Assumptions . . . . . . . . . . . . . . . . . . .
4、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Survey Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 STAGE II DATA COMPILATION AND ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . 55 CLOSING SUMMARY . . . . . .
5、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Table1 API Stage II Cost Study Survey Data Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Figures1 Balance Vapor Recovery System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6、 . . . . . 42 Passive Vacuum Assist Vapor Recovery System. . . . . . . . . . . . . . . . . . . . . . . . . . 43 Active Vacuum-Assist Vapor Recovery System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5v1Stage II Vapor Recovery System Operations & System Installation Costs1 Executive Summa
7、ryStage II vapor recovery is a well-known air quality controlmeasure that reduces ozone precursors from gasoline dis-pensing facilities (GDFs). As a result of its relative high-visual prole, Stage II vapor controls are sometimes proposedas a part of a regional air quality attainment strategy without
8、adequately comparing its overall cost effectiveness to otheravailable control measures. Changes in equipment technol-ogy and system testing techniques continue to raise newissues associated with installing, operating and maintainingcompliance of Stage II systems.The purpose of this Stage II costs st
9、udy partially comes fromthe U.S. EPAs more stringent ozone standard that will bringadditional metropolitan areas into non-attainment status. Theseadditional metropolitan non-attainment areas may considerStage II controls as a priority air quality control measure. As afurther consideration, the U.S.
10、EPA has also implemented anon-board refueling vapor recovery (ORVR) requirement fornew vehicles. It is designed to capture gasoline vapors at thenozzle/vehicle gas tank interface during refueling. Adding to the complexity of the matter, the California AirResources Board (CARB), a nationally-recogniz
11、ed leadagency in the certication of Stage II equipment and systems,has recently promulgated major changes to the CaliforniaStage II vapor control program. This is important becausemany states have linked their Stage II programs to the CARBequipment and system certication process. However, thispaper
12、is focused on the current average cost of installing StageII vapor controls to meet the requirements of pre-EVR CARBapproved systems. This study considered three different types of retail gaso-line outlet (RGO) vapor recovery systems:1. vapor balance, 2. passive vacuum assist,3. and active vacuum as
13、sist. The vapor balance system, congured with a corrugatedbellows over the nozzle spout designed for capturing vapor, hasbeen in use since vapor recovery was rst required. The systemhas been rened and upgraded with improving technology. A more recent technology initially pioneered in the Midwestis t
14、he passive vacuum assist system. Initial versions of thissystem used reciprocal vacuum pumps for each active nozzlepowered by the ow of gasoline to the vehicle fuel tank. Subse-quent versions of this type of dispenser-based approach useelectrical pumps to return the collected vapor back to the gaso-
15、line storage tanks, using electronic signals from the dispensermeters to regulate the vapor pump speed. Finally, the active vacuum assist system has also under-gone many improvements since it was rst used. This systemmaintains a vacuum on the entire Stage II recovery systemand processes the excess v
16、apor collected through a centralvapor processor or burner. A survey of API members and several other sources ofinformation produced average Stage II installation cost datarepresenting company-specic typical Stage II system cong-urations for the three targeted vapor recovery system types.The collecte
17、d data was adjusted to conform to a consistentrefueling system conguration that should not be consideredtypical for the industry. The equipment conguration used inthis paper were an equalized number of nozzles, hoses, dis-pensers and refueling positions for all three types of vaporrecovery systems e
18、valuated. See Table 1. 2 Stage II Program BackgroundIn many major U.S. metropolitan areas, Stage II vapor con-trols are required at gasoline dispensing facilities (GDFs) as apart of an air quality attainment strategy or as part of an airquality maintenance program. Table 1API Stage II Cost Study Sur
19、vey Data SummaryaInitial Capital and Expense CostsRetrot Passive VacRetrot BalanceRetrot Active VacNew Passive VacNew BalanceNew Active VacNozzles/Hoses. . .Dispensers 12. . .6 12. . .6 12. . .6 12. . .6 12. . .6 12. . .6Refueling Positions 12 12 12 12 12 12Design, Engineering and Permitting $2,750
20、$1,500 $2,750 $4,000 $2,500 $4,000Equipment (Nozzles/Hoses, Dispensers, Other Ancillary Equipment)$16,340 $7,385 $14,640 $19,700 $7,625 $15,000Installationb$16,750 $12,100 $16,750 $7,400 $4,600 $8,250System Test $1,200 $750 $1,200 $1,500 $1,000 $1,500Totals $37,040 $21,735 $35,340 $32,600 $15,725 $2
21、8,750Note: aCosts do not include operational costs such as equipment replacement due to failure, periodic testing, or station shutdown for periodic testing. bNot including lost revenues, accelerated depreciation for retrot locations.2 API PUBLICATION1645Given the role that gasoline vapors (in the fo
22、rm of volatileorganic compounds VOCs) play in the formation of ozone,retail gasoline outlets (RGOs) become a high-prole target inefforts to attain the ozone standard. As an obvious source ofVOC emissions, RGOs generally receive high priority for fur-ther controls in metropolitan areas that have not
23、met ozoneattainment standards. The total emissions controlled and thecosts associated with the installation and maintenance of StageII vapor controls are not always adequately compared to otherair pollution control strategies, especially those associatedwith mobile tailpipe emissions (on-road and of
24、f-road) thatmay be less obvious but more cost effective. In December 1988, API published the API Survey ofActual Stage II Implementation Costs in the St. Louis Metro-politan Area. At the time, the average cost of installing StageII on a per-nozzle basis was $1,660. In the 14 years since thepublicati
25、on was issued, new generations of Stage II equip-ment with improvements and variations have been introducedand put into service. For example, the “vapor balance“ systemnozzle is now lighter, easier to use and more durable. A newtype of passive vacuum assist Stage II system has also beendeveloped and
26、 has become prevalent.Up-to-date average costs associated with installing Stage IIvapor recovery systems at typical RGOs are provided in thisresearch. Equipment and installation costs for the more com-monly used Stage II vapor recovery systems are also identi-ed. Signicant effort was made to ensure
27、that the Stage IIcost analyses in this research reect credible, current averages. Cost data was derived from a survey of API member com-panies and interviews with selected Stage II installation andmaintenance experts. Although information was solicited onall types of vapor recovery systems, informat
28、ion on activevacuum assist systems was not received. Other alternativesources were consulted for this information. An explanationof how the data was collected, analyzed, and reduced to a pre-sentation of ndings, is also included in the study. Although costs from several different geographical areasw
29、ere requested for the survey, cost differences between geo-graphical locations did not appear signicant relative to StageII equipment and installation costs. However, at least onerespondent noted that the cost of certied/qualied labor is pro-portional to the distance between a job site and a metropo
30、litancenter. This report does not address equipment performance oremission reduction rates related to the various equipmentcapabilities. Although collected data was API member-com-pany specic, all data was de-identied before it was com-piled and summarized for use in the report. The informationcolle
31、cted was from RGOs with throughputs ranging from100,000 gallons per month to 225,000 gallons per month. Thepaper does not intentionally reect favorably on one Stage IIsystem or equipment manufacturer over another. 3 Stage II Survey Assumptions & ApproachThis study was conceived and scoped to address
32、 the vaporbalance system and two categories of vacuum-assist sys-tems, active and passive. The vapor balance system oper-ates based on the principal of vapor displacement byproviding a vapor recovery return line to collect vapors fromthe vehicle fuel tank pushed out by the incoming liquid gaso-line.
33、 It uses the seal between the vehicle being refueled andthe faceplate of the fueling nozzle. The vapors then movethrough a bellows, which surrounds the nozzle, to pipingback to the gasoline storage tank.Passive vacuum assist systems may be distinguished fromactive vacuum assist systems by their disp
34、enser-basedapproach to vapor recovery. Passive vac-assist stations use owcontrols at the dispenser to return vapor to the gasoline storagetank, whereas active vac-assist systems use a central vacuumunit to recover vapor from the entire system to the tank, pro-cessing excess vapor by incineration or
35、by other means. The earliest version of passive vac-assist systems relied onreciprocal pumps within each dispenser housing that inher-ently varies the speed of vapor recovery based on productow through the dispenser. The greater the product ow, themore gasoline vapor is recovered. Newer versions use
36、 electri-cal pumps to return recovered vapor to the gasoline tank,where the amount of vacuum generated to recover vapors isbased on the gasoline ow rate detected electronicallythrough the dispenser meter. As the basic principal behind the passive vac-assist systemis to recover vapors equivalent to t
37、hose generated during therefueling process, passive vac-assist systems do not employvapor processors. For this reason, the ratio of product dis-pensed to the vapor recovered is important to the effective-ness of the system. Consequently, some regulators have placed increasedemphasis on A/L testing t
38、o ensure that passive vac-assist sys-tems remain within certied 95% effectiveness levels. A fewagencies demand compliance testing at greater than theannual frequency outlined in the California Air ResourcesBoard (CARB) Executive Orders certifying the passive vac-assist systems. This more frequent te
39、sting increases theannual maintenance costs borne by those operating passivevac-assist equipment. A signicant number of active vacuum processor-typesystems are in use. These systems differ from the passivevacuum assist systems chiey in the deployment of a single-unit vacuum generator applying a vacu
40、um to the whole vaporrecovery system. This application actively removes vaporsduring gasoline dispensing. Because these systems generateexcess vapors with the centrally applied vacuum, they eitheruse incinerators or other types of treatment technologies toprocess the recovered excess vapors. STAGEII
41、 VAPORRECOVERYSYSTEMOPERATIONS& SYSTEMINSTALLATIONCOSTS33.1 SURVEY ASSUMPTIONSThe assumptions used in the development of the surveyand the compilation of survey data and other informationused to formulate this paper were based on the followingdescriptions of Stage II vapor control systems. 3.1.1 Sta
42、ge II Vapor Balance System The vapor balance system is one of the original Stage IIcontrol technologies. (See Figure 1.) This system uses thenatural balance of pressures between the product drawn fromthe retail gasoline outlet (RGO) storage tank developing anegative pressure, to the positive pressur
43、e developed as fuel isdispensed into the vehicle fuel tank without the use of addi-tional motors or pumps. The net effect is the ow of vaporfrom the vehicle fuel tank back to the RGO storage tank asthe fuel is dispensed into the vehicle tank. The bellows nozzle is a key and most recognizable element
44、of the balance system. The system works when the nozzlewith its bellows over the spout with a faceplateis snuglyplaced over the vehicle fuel tank opening, thereby creating aseal.The fueling hose is typically coaxial. The gasoline owsthrough the inner hose while vapors are returned to the under-groun
45、d storage tank (UST) through the outer hose. Liquid fromcondensation or splash back may pool in the lowest part of theouter hose and block the vapor path, thereby defeating the sys-tem. For this reason, liquid collection tubes or devices are ofteninstalled in the hose for continuous removal of this
46、liquid.The installation of a pressure/vacuum (P/V) valve on theend of the tank vent pipe has been shown to improve thevapor balance systems ability to contain vapors in the totalsystem.3.1.2 Stage II Passive Vacuum Assist System Of the two types of vacuum-assist vapor recovery, the new-est systemand
47、 one gaining in popularity primarily due toconsumer preferenceis referred to as a passive vacuumassist system. (See Figure 2.)Passive vac-assist systems use a dispenser-based technol-ogy to recover vapor from the refueling process. In previousversions of the passive vac-assist system, the amount of
48、vaporrecovered may be regulated by the use of a reciprocal pumpin the dispenser, where the dispensing fuel passes throughone section of the pump and generates a vacuum in anothersection. This vacuum pulls gasoline vapor from the vehiclegasoline tank ll area to the gasoline storage tank on aroughly 1
49、:1 ratio. Over the past decade, modications to the initial concept ofthe passive vac-assist system have emerged and have proved tobe very popular among RGOs nationwide. These newer ver-sions typically use electric pumps to return vapor to the gaso-line tanks. The 1:1 ratio of the vapor recovery process of thesenewer versions is maintained by regulating the speed of the dis-penser-based electric vapor pumps by monitoring the dispens-ing rate electronically through the dispenser meter. To the customer, the passive vacuum ass
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