Bulletin 61: Hydrometers, Thermometers, & Accessories

The symbols on the left side of the charts below may help you to select the hydrometers you should order. Hydrometers and thermohydrometers marked with these symbols have special ranges that avoid the need to purchase two instruments to cover the range for aviation fuels. ASTM has assigned special numbers and has officially approved them. For example, most jet fuels have an API gravity range that requires ASTM S555HL but there are some fuels that need ASTM S554HL to reach 37° API. So the new ASTM S561HL, with a range of 37-49°, covers all jet fuels. ASTM S562HL covers Avgas. Each symbol also indicates additional qualities as described below:

GTP-1857 is shown. Other models may vary in appearance.

These hydrometers are thermometers have been shortened so they will fit in Aljac JM-3001 samplers when the lid is closed. Graduated spacings remain the same as ASTM instruments but the ranges have been shortened in some cases.

GTP-3312-1GB is shown. Other models may vary in appearance.

Graduated to 0.01, 320mm length. No thermometers are included.

Any of the hydrometers in this brochure may be furnished with a NIST Traceable Certificate of Calibration at extra cost, upon request. This certificate shows actual data at three test points as required by ASTM E-100 (for hydrometers) or the test points required by ASTM E-1 (for thermometers). Actual readings are resolved to 1/10 of the smallest scale division. The test methods and NIST standards that are used, as well as uncertainties of measurement and all other necessary data to maintain full traceability are provided.

This calibration is performed by an independent calibration laboratory which is accredited to the international standard ISO/IEC 17025. Copies of the laboratory’s ISO 17025 Accreditation are available upon request for your qualified vendor files. To order this certificate, add the suffix “C” to our GTP number. There is an additional charge for this service.

These circular calculators eliminate the need for books of tables for making gravity or density corrections to standard temperature. Easy to use and very fast – about half a minute.

There are two methods that you can use. The best way is by cooling. The more difficult way is by using heat. The object of both methods is to get the broken pieces of mercury into a chamber where they can rejoin. The bulb at the bottom is large enough to hold all of the mercury in the capillary when it is cooled in dry ice. If there are pieces of mercury left in the capillary after cooling, carefully tap it vertically on a padded surface. Allow the thermometer to warm naturally (do not heat it) in a vertical position, and observe the mercury column as it ascends into the capillary to be certain it is intact.

If dry ice is not available, you must use heat. Thermometers and thermohydrometers that are offered by Gammon Technical are made with an “expansion chamber” at the top of the capillary tube. The purpose of this chamber is to provide over-range protection in case the thermometer is heated beyond its scale range. This chamber may be used to rejoin separations provided that the amount of separated mercury is very small (not more than a few scale divisions in length). The thermometer should be heated in water that is warmed only slightly higher than its maximum reading. The objective is to apply only enough heat to urge the broken pieces of mercury into the expansion chamber, followed by a small portion of the main (intact) column. DO NOT USE FLAME! Great care must be taken to not fill the expansion chamber more than halfway, because the developed pressure can break the glass. Remove the thermometer from the heat, maintain it in a vertical position, and observe the mercury column as it retreats into the capillary to be sure it is intact.

CAUTION: When installing a floating suction, do not enter the tank until all fuel vapors are cleared.

HORIZONTAL TANKS
In most cases it will be necessary to remove the float assembly before installation is attempted. This simply requires removal of one stainless steel cotter pin. If an attempt is going to be made to install a floating suction without someone working inside, we recommend Style 5 with the riser flange bolted to a spool piece welded into the cover of the manway. Style 6 is another option. Assembly can be inserted through the manway until the cover comes to rest on the top of the manway. Care must be taken to insure that the swivel turns in the right direction so that the float is located above the suction arm. Also, a special provision must be made for attaching the test cable by threading it through a special port in the manway cover. The minimum manway inside diameter to permit installation of Style 5 without removing the float is shown in the following chart for each size:

This chart does not apply to Styles 1, 2, or 3 because the limiting factor on being able to insert these long suction arms is whether or not the arm will contact the bottom of the tank before it can pass through the manway. We have developed simple charts for each size of floating suction for a wide range of tank diameters, manway diameters, and manway lengths so that we can quickly determine the maximum suction arm length that can be inserted in your tank. This is why you must give us the dimensions of your tank when you place an order. It should be understood that it will be necessary in most instances to remove the float and swivel before installation if Styles 1, 2, or 3 are selected.

SUCTION ARM LENGTH for our standard designs of Styles 1, 2, and 3H is based on the assumption that the fitting in your tank is positioned so that the arm will operate freely without contacting the end of the tank. The customer is expected to inform us if he wants a non-standard suction arm length. We do not recommend allowing the arm to rise to an angle greater than 45°.

TEST CABLE INSTALLATION should be arranged so that the cable will not be bent at a sharp angle when the yardman pulls upward. Ideally, the opening through which the cable is installed should be as close as possible to the point where the center of the float contacts the top of the tank (see typical arrangement for Style 4). The cable may be attached to the lower face of a pipe cap that will close the top of the access port.

All connection flanges for all styles are 150# ANSI-RF unless otherwise specified.

VERTICAL TANKS
Floating suctions for vertical tanks must be disassembled during installation. The purchase order must specify the manway diameter so that a float can be selected that will pass through. If the arm length/diameter ratio is very great, we add intermediate legs as necessary, especially if the outlet flange is lower than the inlet, causing the arm to remain full when the tank is empty.

If the height of the tank is greater than 75% of the diameter, the arm will rise to such a steep angle that it may hang up. One option is for us to add a restraining cable and let the fuel rise as far above the float as necessary (see Style 3VR). The other option is to add swivel joints and use multiple arms (see style 3VA); we have had to use as many as four in very tall, small-diameter tanks. Special provisions are made to guide the float and arms.

At Gammon Technical Products, we have sold grounding clamps and millions of feet of cable over the decades, but we have never made our own unique clamp – until now. The Gammon Gator is designed to surpass all previous clamp designs in every way. It is easier to use, inexpensive, and 100% made in the USA.

Includes hex end cap to secure cable

Heavy-duty Mueller type clips. 1 dozen minimum order.

NFPA requirement, you must bond before removing cap on aircraft

Static Bonding Reels provide the automatic retraction and compact storage of 50, 75, and 100 foot cable and clamp assemblies. Designed to function under extreme environmental conditions, the 50 and 75 foot cable length models meet USAF MIL-R-83232B and U.S. Government specification A-A-50696.

A patented latching mechanism holds the cable at any desired length. A slight pull on the cable releases the mechanism causing retraction. Retraction need not be attended. The retraction speed is automatically governed by a special brake assembly designed to limit the retraction speed from two to seven feet per second. Steel components and a cantilever-type frame, which support the reel assembly, are designed to function under the most adverse conditions. Baked-on MIL spec red finish and gasketed drum construction protect operating parts from corrosion. Bearing surfaces are permanently lubricated.

There is no question in our opinion: these are the most reliable air eliminators money can buy. Stainless steel float and mechanism, Viton A seal, 3/4” NPT in and out. (1/2” on special order), 1/16” air outlet orifice operates up to 208 psi. Air release rate at 150 psi is 6.04 cfm. Larger orifice sizes: 3 available on special order but operating pressures decrease. Structural pressure rating is 250 psi on all models. Repairable replacement parts are available.

STAINLESS STEEL MODEL – High Air Flow
Non-repairable. At 150 psi, releases air at 9.44 cfm. Maximum operation pressure 400 psi. Structural pressure rating 500 psi.

Designed to fit threaded bottom coalescer elements. The socket is 1/2” square drive for torque wrenches and extensions. This adapter is needed to attach a torque wrench to coalescer elements.

Prevents drain-back

To be installed above the air eliminator

Viton seal – all stainless steel

Designed to fit threaded bottom coalescer elements. The socket is 1/2” square drive for torque wrenches and extensions. This adapter is needed to attach a torque wrench to coalescer elements.

Relieves excess pressure caused by thermal expansion of the fuel. Be sure to specify relief pressure setting.

Note: 150psi is our standard pressure relief valve setting. Other settings are special order and are non-refundable.

Connect the suction and discharge hoses as desired. Attach cable clips to battery. Turn on the switch. Open filter vent.

Note: The DC pump has a permanent magnet motor and must be connected correctly or it will run backwards.

The versatile Jet Test QD® has many uses other than those shown on Bulletin 14. This permanently installed, impact resistant, quick disconnect is unique because only its stainless steel hex is exposed.

Standard Jet Test QD®s require the long actuator. Refueling nozzles such as those made by Avery Hardoll (now known as Meggitt) use a shorter actuator because the long version would interfere with the nozzle strainer. Short versions have suffix S or AH in the model number.

See below for components and variations of these two assemblies.

Viper Additive Injectors are designed to accurately and reliably inject a wide range of additives into a flowing stream of fuel or other hydro-carbon liquid. All fluid-wetted components are 300 series stainless steel. For maximum accuracy, temperature range, and durability, we have a wide range of custom rubber seals available.

Available with or without controls, these injectors can be directly controlled by the new advanced LC, TCS, and other meter computers for simplicity and record keeping. Made in USA.

The Viper pump is a simple concept. A double-acting, positive displacement, solid stainless steel piston pump, tested to provide a long life on clean additive before seal change of 30,000,000 gallons. All rubber (check valve) and PTFE (shaft and piston) seals, for reliability and accuracy. Self-cleaning check valve design, inlet strainer and main seal leakage detector. Compressed air powered, electronically controlled.

Our Heavy Duty mechanical adjuster is linear so if you change the adjuster 10%, the additive output changes 10%, unlike some competitors. Tested to -50° F. Viper pumps in service as long as 15 years have never needed adjustment, just occasionally new seals or a strainer cleaning. Checking is simple, flow volume into a test jar is the same as flow into the fuel stream.

Flow rates up to 1,200 gpm, additive rates up to 1,500 ppm. Includes a special test valve, high-visibility flow indicator, and atomizing injector nozzle.

The Viper Scorpion is a smaller version of the Viper. Flow rates up to 500 gpm at 100 to 1,000 ppm. Compact and less expensive, but just as accurate and reliable.

The Viper Scorpion Mini is a simplified additive injection system without mechanical adjustment. Developed for use specifically with a meter computer such as the TCS or LC system. Additive meter required.

The Viper Concord was developed long ago to inject CI/LI additive for the Concord SST. Designed to accurately inject additive at as low as 20 ppm at flow rates up to 1,000 gpm, the Concord was “brought out of retirement” to join the Viper line. Interestingly, the Concord has no Piston seal, utilizing a clean “return” design to prevent leakage.

The “brain” is a simple control, preset before shipment. No programming needed! The Digital Viper takes a pulse from your existing meter, and paces the additive flow rate to match the fuel flow. When interfaced with an on-board meter computer, can inject additive at different ratios for different customers, simply! A very simple system, using robust parts specifically built for this purpose.

The Viper Eclipse builds on the Digital Viper. It has a more advanced brain and a digital display. But don’t worry about programming, we do it all, no field programming needed. It has self-checking and self-adjusting ability, as well as a digital display with ppm, percent, gallons (or liters) of fuel and gallons (or liters) of additive displayed. It has warning and shutdown modes if additive concentration falls out of the set range. Includes additive meter calibration and priming modes. The Eclipse adds an additive meter and an intelligent “permissive” control system. The operator cannot dispense fuel without first telling the Viper Eclipse to inject, or not to inject additive. No more “forgetting” to turn the injector on or off. Maintaining a 1,000 operation memory of additive and fuel dispensed, date and time.

The Viper Eclipse Control System can be used with any of the Viper pumps.

Order the GTP-9076, with additive type Q (Stadis 450/corrosion inhibitor). Fill out all other boxes on the chart above as necessary for your application.

To meet API-1581, you should have a 3-way valve. Our 3-way valve meets this requirement and is used to check calibration as well as to check free movement of the piston.

1. Establish flow in the system. The gauge should indicate a pressure drop.
2. Push the test button. The piston should travel to the bottom of the scale.
3. Release the button and stop flow in the system. The piston should return to zero.

If the piston returns to zero, you have not only calibrated the gauge, you have checked it for free moment across its entire range. If the piston moves slowly, the filter (located in the top of the gauge) may be clogged and need replacement. This calibration technique is accepted by all major oil companies, all major airlines, and military services worldwide. Gammon Gauges™ have been in service in virtually every major airport in the world for as long as 30 years and we have never heard of or seen a single gauge go out of calibration. Occasionally a piston will stick after many years in service, but hand cleaning with “Scotch Brite” plastic abrasive will make it as good as new (Note: Do not clean with sandpaper or steel wool). Replace the o-rings and reassemble.

If differential pressure suddenly increases or a facility is operated without personnel monitoring the differential pressure, filter element failure can occur. This new switch is unique. It adds differential pressure control at a low cost using a non-powered proximity switch. This simple double-sealed switch is ideal for use in PLC (miniature computer) and relay controlled systems. The connection box is rated NEMA 4X.

Control operations are also available if you don’t plan to use an external control. We have weather-tight and explosion-proof versions.

We strongly recommend a 3-way test valve for properly testing the Gammon Gauge™ and Proximity Switch and/or system.

Any Gammon Gauge™ can be converted to include the new proximity switch.

Note: To meet IATA JIG Bulletin 58, order one of the “KS” options for key switch reset and test functions. The ATA-103 does not require this. For vehicle mounting, we recommend the weather-tight housing.