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5 © Are tight connections at the fill adaptor important?
<br />Alserious Yes, very important! In order for any similar valve to do its job, a tight connection at the tight fill adaptor is essential. A spill may result when the valve closes, causing a hazard and environmental contamination -if the delivery elbow is
<br />not securely coupled to the fill adaptor. Delivery personnel should be trained to make certain a good positive connection
<br />between the delivery elbow and tight fill adaptor is always made. Similarly, all connections between the UST and delivery
<br />transport must be secure during delivery.
<br />6 © What about "loose fill" applications?
<br />AThe DPW 61-S0, or any other in -tank positive shut-off valve, should not be used in applications where there is not a
<br />positive, mechanical, sealed connection between the delivery fittings on the hose and tank. Serious hazard or environmen-
<br />tal contamination may result in "loose fill" or "sealing sleeve elbow" applications when the valve closes and the delivery hose is
<br />full of liquid.
<br />7 © How does the hose drain?
<br />WAfterthe valve has closed, a small bypass valve in the DPW 61 -SO remains open. This enables draining the contents of the
<br />delivery hose into the UST. The delivery attendant simply closes the valve on the transport, waits for the hose to drain,
<br />makes his disconnect atthe truck and walks the hose down, emptying its contents into the tank. By the time the delivery elbow is
<br />disconnected, the main valve will re -open, allowing the tank contents to be gauged normally.
<br />The hose drains automatically. The DPW 61 -SO has no external levers or controls that must be manually operated to drain
<br />the delivery hose. Such manual controls could accidentally or intentionally be used to defeat the purpose of the valve by keeping
<br />it open, even with an overfilled UST.
<br />80 Whatabouta "minimumflowrate"?
<br />FAI The DPW 61 -SO is activated directly from high liquid level. It does not rely on high delivery flow rates to produce a vacuum
<br />and trip a latching mechanism. Therefore, the DPW 61 -SO does not require a minimum flow rate of 150 gpm to operate
<br />properly. A partially open, throttled valve on the delivery transport may allow a flow rate lower than 150 gpm.
<br />g ©Can the UST begauged?
<br />Al Yes, the
<br />DPW 61 -SO re -opens automatically after the hose drains, to allow "sticking" of the UST.
<br />10 © Can I store mygauge stick in the riser pipe?
<br />❑No. Any mechanical obstruction in the flow path may prevent the DPW 61 -SO valve from closing properly. This could cause
<br />A► an overfill, a spill, serious hazards and environmental contamination.
<br />11© Whatif the drivers try to continue to overfill the UST?
<br />[A] Should the delivery attendant attemptto drop additional fuel once the main valve has closed, either it will be a very slow
<br />process through the bypass valve only; or each time he drains the hose to re -open the main valve, and then re -starts flow
<br />(even at reduced rates), the valve will close.
<br />However, if the attendant is persistent (or absent from the site) in putting additional fuel into this overfilled storage tank,
<br />eventually 300 gallons (in an 8,000 gallon tank) will raise the floatto LEVEL B. This is approximately 98% of tank capacity. At this
<br />level the float mechanism will act to close the bypass valve, providing a practically tight positive shut-off -- preventing further
<br />delivery into the severely overfilled UST.
<br />Only by drawing the liquid level down a minimum of about 100 gallons will the bypass valve re -open allowing the delivery
<br />hose to be drained.
<br />Once again, all this happens automatically in direct response to the rising liquid level. Manual overrides, controls, levers,
<br />etc., designed to speed the hose draining process may also serve to defeatthe purpose of the overfill prevention valve, as well as
<br />being a source of maintenance and repair costs. A properlytrained delivery attendantwill find the DPW 61 -SO easyto accept as
<br />part of the normal UST system.
<br />12 ©Does the OPW 61-SOrestrict the deliveryflowrate?
<br />[A] Yes, very modestly depending upon the configuration of the UST, delivery connections, productflow rate, etc. Some
<br />operators may experience a slight reduction in deliveryflow rate, e.g. 10-15%. This is true with the DPW 61 -SO, and other
<br />shut-off valves available today. However, in delivering for example 3500 gallons of product at 350 gpm average, the expected
<br />deliverytime would be 10 minutes. The use of an overfill prevention valve may add 1-11/2 minutes to the process. Considering the
<br />total"on-site" time, this is a small operational price to payfor overfill prevention, and environmental protection.
<br />-2-
<br />• •
<br />•
<br />Liquid
<br />OPW 1
<br />Spill Container, typical
<br />a 5 o Grade Level
<br />OPW 61 -SO OVERFILL 6" or per",Typical UST
<br />PREVENTION VALVE local requirements
<br />13 © How is the OPW 61 -SO packaged?
<br />The DPW 61 -SO may be shop or site assembled. No special skills ortools are required. Complete, detailed instructions are
<br />[Alprovided with each unit.
<br />The DPW 61 -SO is furnished unassembled, with all the parts necessaryto install in a UST buried a maximum of 5 feet and
<br />having a diameter of no more than 8 feet. Complete instructions including a list of parts supplied is furnished with each unit. The
<br />installer should contact his DPW distributor or DPW directly (800-422-2525) if there are parts missing. Other models of the DPW
<br />61 -SO to accommodate deeper bury depths or larger diameters may be available; contactyour DPW Distributor or DPW directly.
<br />• 14©"at about replacementparts?
<br />It is imperative for the proper operation of the DPW 61 -SO that only the parts supplied with the unit, or by DPW as
<br />replacements, be used in assembly of the valve.
<br />The upper drop tube is a special heavy wall design. A standard drop tube must not be substituted! If you need a special
<br />length or have other problems call us on our toll-free number.
<br />No internal replacement parts forthe valve are available.
<br />15 © Whatdolneed toknowaboutmy UST?
<br />All. Only 2 measurements on a UST are required to properly assemble an DPW 61 -SO for an installation: The distance from the top of the riser to the top inside of the UST. This locates the valve properly inside the tank to
<br />achieve initial shut-off at about 95%. Installing the valve closer to the top may prevent it from operating properly.
<br />2. The distance from the top of the riser pipe to the bottom of the tank. This determines the overall length of the DPW
<br />61-S0. Consideration must be given to local codes or operating practices that dictate how close to the bottom of
<br />the tank the lower tube should be.
<br />With these 2 dimensions the DPW 61 -SO maybe site or shop assembled for installation. Since all tanks are different, take
<br />care to install an OPW 61 -SO only in its corresponding tank.
<br />16 ©What about ball float vent -valves?
<br />[AlAnother assembly consideration is the presence of a ball float vent valve similar to the 0 P 53V series. The DPW 61 -SO
<br />may be used in conjunction with a ball float vent -valve, however, this is optional. A properly assembled and installed DPW
<br />61 -SO will function as an overfill prevention valve, making a ball float vent -valve used for this purpose redundant. If a ball float
<br />vent -valve is present, the DPW 61 -SO must be installed such that its initial shut-off is below the seating of the ball float vent -valve.
<br />This will ensure proper operation of the OPW 61-S0. This is covered in the instructions provided with each OPW 61 -SO.
<br />17 © Does the OPW 61 -SO fit in a 4"riser pipe?
<br />• Yes, the OPW 61 -SO was designed to slip easily into a standard schedule 40, 4" riser pipe. Difficulty in removing the existing
<br />Alfill tube (if there is one) means there maybe an obstruction in the riser pipe. Look for burrs, deformations, excess tank
<br />lining material or other projections that may interfere with easy insertion of the DPW 61-S0. If welded, seamed pipe has been
<br />used for the riser, the internal weld bead may interfere with the DPW 61 -SO and prevent installation. If the DPW 61 -SO won't slip
<br />in easily Don't Force It! Damage to the valve may result if excess force is used. Examine the riser pipe carefully, determine the
<br />nature of the obstruction and take appropriate steps to remove it.
<br />-3-
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