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HomeMy WebLinkAboutDOMESTIC TANKSs.1�l :lN.11T1T►�TI r6lPROPANE edgmlion 8 research COUNCIL Ranked 41 by PERC in ovorail performance ranking for Protective Coatings applied on undergmund propane Tanks T.1711NITY ME Corim ing Our Worlds Energy"^ JERGROUND 0f1 SCANNED D BY uve coo* PROUDLY FINISHED WITH SHERVI INe WILLIAMS. Ak �L TRINITY* pi�r .- Containing Our Worlds Energy'" NFPA Rated with t tanks Applil vviu 1 n General Specifications to the latest edition of the ASME code for Vessels, Section Vill, Division 1. Complies with 1250 psig from -20' F. to 125° F. All tanks may be ad to a full (14.7 psi) vacuum. 'inish: Coated with epoxy red powder. ( Tanks coated epoxy powder must be buried). For Aboveground use, iy be coated with TGIC powder. Ile federal, state or local regulations may contain requirements for protective coatings and cathodic In. The purchaser and installer are responsible for ice with all federal, state or local regulations. -' WITHDRAWAL VALVE FLOAT OTICE�04 ` GAUGE LP' c� ANODE CONNECTION FILLER ' OVALVE SERVICE/ � NAME MULTIVALVE PLATE RELIEF VALVE FITTINGS LAYOUT UNDER DOME AGUG VESSEL DIMENSIONAL INFORMATION All vessel ', dimensions are approximate WATER OUTSIDE HEAD OVERALL OVERALL LEG LEG WEIGHT CAPACII DIAMETER TYPE LENGTH HEIGHT WIDTH SPACING 120 Wg ' 24" Ellip 5'- 5 13/16" 3' - 0" 10 1/8" 3' - 0" 245 Ibs. 454.2 L III 609.6 mm 1671.3mm 911.4 mm 257.2 mm 914.4 mm 111.1 kg. 250 wg 31.5" Hemi 7'- 2 1/2" 3' - 7 1/2" 12 3/4" 3' - 6" 472 Ibs. 946.3 L, 800.1 mm 2197.1 mm 1104.9 mm 323.9 mm 1066.8 mm 214.1 kg. 320 wg. 31.5" Hemi 8' -11 3/4" 3' - 7 1/2" 12 3/4" 4' - 0 1/4" 588 Ibs. 1211.2 800.1 mm 2736.9 mm 1104.9 mm 323.9 mm 1225.6 mm 266.7 kg. 500 wg. 37A2" Hemi 9' -10" 4' -1 7/16" 15" 5' - 0" 871 Ibs. 1892.5 L 950.5 mm 2997.2 mm 1255.7 mm 381.0 mm 1524.0 mm 395.1 kg 1000 Wg.; 40.96" Hemi 15' -10 13/16" 4' - 4 5/16' 16 1/4" 9' - 0" 1729 Ibs. 3785.0 L i 1040.4 mm 4840.6 mm 1344.6 mm 412.8 mm 2743.2 mm 784.3 kg QUANTITY FULL PER LOAD STACK 96 12 63 9 45 9 30 6 15 1 5 Rev: Jan. 27, 2016 Why Tan Corrode Undergrod steel tanks corrode due to an electrochemical reaction between "e tank and the surrounding soil. The process of corrosion occurs duto small voltage differences on the steel surface that result In the flow j f DC current from one location to another. Where current flows from a tank into the soil corrosion occurs. This location is called the anode 1 a corrosion circuit Where currentflows from the soil to the tank, no co' osfon occurs. The progress of corrosion is determined by the amount f current flowing between the anode and the cathode and whether they ocations of the anode/ cathode remain constant over time. Corrosion ra es are generally higher in wet soil environments since the conductivity, I�f the soil promotes the flow of DC current In the corrosion circuit. Corrosion g 'perally exhibits itself on underground tanks in etcher a general over i rusffng or more commonly, a pitting attack Pit locations may result f m metallurgical conditions of the steel suraface or variations su , moisture concentration, o soil concentration!, etc. xygen L r _ Preventing 9 Corrosion Protecting underground tanks from corrosion is easilyachieved bythe use of two commonly applied Protection methods: external coating and ` cathodic protection. These two methods are complementary and should b a used in conjunction with the other. An effective external Protective ating insulat the steel from the soil environment, thus Preventing s flow of corro on current from the anode to the cathode. An effective Imal coating nprotectover99%Ofthe tanksurfacearea. However, coating is perf' ct. Damage from construction or soil stresses create r defects, whit it may result in accelerated corrosion at the defect JULIIUUIU prevents osion at those )C current from an exte nalcsorurce, forcing the tank byapplying athode. Applicaff n of sufficient DC current to the tank will prevent any orrosion from oc '�rring. The two general 'stems are sacrif lal and impressed currents Sacrificials of lsystems aic re set when the am unt of current required for the protection is small, tch as in underg pund propane tanks. Impressed current systems e more common y. used for large structures such as large diameter Pellnes. Electnca isolation of the tank from metallic piping systems d electrical grout ds is critical for the cathodic protection system's `ecoveness. III W �acrificiai Cat odic Protection works crifIclal systems 1 rk by Creating a galvanic connection between two different metals. The most common anode material Is magnesium, which when coupled to steel results in DC current flow from the magnesium to the steel. The open circuit potential of steel is about -0.50 volts referenced to a copper sulfate electrode. The open circuit Potential of magnesium is about -1.55V to-1.80V. By connecting the two metals together, the difference of 1 to 1.25V volts results in current flow to the tank that overcomes the natural corrosion cells that exist on the tank. With this current available to the tank, no corrosion occurs. Magnesium Anodes There are a variety of anode sizes and alloys used for cathodic Protection. The two primary alloys are designed as H-1(or AZ62) and High Potential. The H-1 alloy is produced from recycled magnesium and has an open circuit potential of approximately—1.55V. This alloy is well suited for protection of underground propane tanks. The High Potential alloy is 99% pure magnesium having an open circuit potential up to -1.8V. This alloy should be used for soil applications over 10,000 ohm -cm resistivity. The two most common anode sizes used for underground propane tanks are 9 lb. and 171b. The size designation relates to the metal weight 10' of #12 TW insulated wire is attached to the anodes. Anodes are then backfilled in a mixture of gypsum, bentonite, and sodium sulfate to lower the electrical resistance of the anode to soil. The mixture is a low cost, nonhazardous, electrically conductive backfill. The anode and backfill is then packaged In a cotton bag and either a cardboard box or Paper bag. Actual shipping weight of these anodes with backfill is 27 lb. and 45 lb. Application Recommendations Magnesium anodes can protect underground tanks In most soil conditions. The H-1 alloy is generally very effective, The following chart :.provides size and quantity recommendations forvarious sizetanks based on conservative design assumptions. This char` covers soil conditions up to 10,000 ohm -centimeter resistivity. Resistivities higher than 10,000 ohm -centimeter generally represent very dry soils. Verification of soil resistivity can be performed through soil analysis. Contact us for design recommendations in locations where soil resistivities exceed 10,000 ohm -cm, or if there is no effective external coating on the tank. considered in the cathodic protection designThe propane service line from the tank to the ho, service fine us he se also must be unlest Is plastic. All underground steel pipe should be extemthe coated with a corrosion resistant material. The service line should be electrically isolated at the house with an insulating fitting or union. If service pipe is Mess than 50' in length, the tank anodes will provide sufficient current to protect both tank and pipe. For longer lengths of pipe, an additional anode may be required at the house connections. If another metallic material such as copper is used for service piping, the pipe should be electrically isolated tram the tank at the fill pipe connection. Copper and steel create agal vaniccouple that will accelerate Corrosion of the steel tank when directly connected to copper piping. Generally, copper piping does not require cathodic protection. ll Typeennesojlslayf Sand' vel, Rocky k Cap..; to 5000 nni:,cm.' 5000 to 10000 ohm -cm jai.) rti� oi : Size • Alloy 20 9# H-1 50 50 ;i9i4 H y< 9# H-1 25 2 H-1 ' 2 H-1 e 9 2 H-1 00 t7�,^��zy 9# 4 H-1 00 #25, 2`: 4 H-1 30 'Based on J.tta. % effective extemal coating, 2 maIR2 current de~ 90- yearAnode Anode Inst Ilation 1. Deter ne size and quantity of anodes from application chart. 2. When I single anode is Installed, it should be located near the tank ce ter on either side of tank. 3. When uitiple anodes are installed, space them evenly around the tanil See examples below. ano je 2 anodes 4 anodes o 4. Anodes < papersac anode. If before ins 5. Install anc at least as in location the better. 8. After placli and extent 17. Cover the pour 5 gall backfill. W 8. Connect tt resistance tank fill pip, tank. All cc material. 9.Ideally, the pipe within 1 subsequent anode outpu ),Verify perfoi Procedure. shipped in either cardboard boxes or multi -wall Remove outer container and bury the cloth bagged 3de is supplied in plastic bag, remove plastic bag ling. s approximately two to three feet from the tank and ep as the center line of the tank. Anodes work best Nith permanent moisture, so generally the deeper the anode, stretch out the anode connection wire rer to a connection point on the tank fill pipe. )de with approximately six inches of backfiil and s of water on the anode to saturate the prepared r is necessary to activate the anode. anode wire to the tank with a low electrical inection. Examples are threaded stud on' the r any accessible metallic connection point to the ections should be coated with a moisture -proof c connection is made in the area of the tank fill covered dome. With access to the anode wire, Ling of the tank can include measurement of Id verification of performance. once of the anode using an appropriate test Mechanic -_ connection Under Dome Cathodic Protection Testing Procedure Equipment Needed: Digital Voltmeter, Red Test Lead Min.12' Long & Black Lead Min. 2' Long, Reference Electrode (Copper/Copper Sulphate Half -Cell) STEP 1: Using a digital voltmeter insert the red test lead into the Volt jack of the meter and select the 2 or 20 volt DC scale. Clip red test lead connector to an uncoated metallic area of the tank, preferably to the fill pipe multivalve. A good solid connection Is very important. (DO NOT connect to shroud). STEP 2: Insert the black test lead into the Common jack on the meter, and connect the opposite end of the lead to a charged reference electrode (% cell). STEP 3: Remove protective cap from the porous plug at bottom end Of electrode. Place porous plug end into native soil (remove grass if necessary) at four locations around the tank (one on each side of the tank, and one at each end of the tank). if difficulty is encountered obtaining readings, moisten soil with water or dig % cell deeper into the soil. STEP 4: Record all four meter readings on an appropriate form. The least of all four readings should be a minimum of-0.850v or more negative. {Note: If any of the four readings are below (less negative) -0.850v then the tank is not fully protected}. Charging Reference Electrode STEP 1: Unscrew and remove porous plug end of new reference electrode. Add delonized or distilled water to the copper sulfate crystals, filling electrode completely. The solution will turn blue in color and there should always be excess crystals at the bottom of the tube. DO NOT USE TAP WATER, ZTEP2: Replace porous plug end of electrode and place in an upright Position so that the porous plug end Is facing in the down position and let stand for 1 hour before use. This will allow the porous plug to become completely saturated before use. Caution: Do nntallow electrode to contact oil, road salts, or other substances that may contaminate the solution by absorption through porous plug. no not allow electrode to freeze_ for use as a first stage regulator on any domestic size ASME or DOT container in propane gas ations requiring up to 1,500.000 BTU's per hour. The regulator is factory set to reduce container ure to an Intermediate pressure of approximately 10 PSIG. ng L 403TRV9 ��' FNPT ''/2" FNPT/3z' 10 PSIG Over Outlet 9:00 1,500,000 t ' ximum DOW based) on inlet pressure 20 PSIG higher then the regulator setting and delivery pressure 20% lower than the regulator atun� g and delivery pressure 20% lower than the setting. accurate first stage regulation in two -stage bulk tank systems. Reduce tank pressure to an ate pressure of 6 to 10 PSIG. Also used to supply high pressure burners for applications like furnaces or boilers. Also incorporated In multiple cylinder installations. ing Dnaf®a ration '/2" F. NPT %" F. NPT 4 ., F. POL 10 Yes I 2,500,000 W 03TR96 I '/" F.NPT Wheni 1� Fan used for flnel stage pressure control, must either incorporate Integral relief valve or separate relief valve should be speci0ed in accordance with NFPA Pamphlel58. Maxi um flow based on Inlet pressure 20 PSIG higher than the regulator setting and delivery pressure 20% lower than the setting. Designed to reduce first stage pressure of 5 to 20 PSIG down to burner pressure, normally 11" w.c. Ideal for medium commercial Installations, multiple cylinder Installations and normal domestic loads, ®a d' ring onformatoon The L1 burner Me 16 °GN ZU � B46 '/2" F. NPT 11" W.C. 146R" #28 at 10 9" to 13" 3/" F. NPT Drill PSIG ,N c Over Inlet 935,000 ess Inlet 66R' 4" F NPT it design flow based on 10 PSIG Inlet and 9" w.c. delivery pressure. R Back Mount Regulator is designed to reduce first stage pressure of 5-10 PSIG down to ire normally 11" w.c. Designed as a second stage regulator for smaller applications with flow up to 450,000 BTU/hr. and are ideal for homes, mobile homes, and cottages. Inforlt Sfion 72 r-.rvt- t 11" W.a. At 10 9" to 13" R /" F.NPT a�Q , F NPT/az° PSIG Inlet W c Over Inlet 450,000 flow based on 10 PSIG Inlet and 9" W.C. delivery pressure.