IntroductionAbout UsThe Relevance of JFTOT TestingThe Problem of Performance Testing

Appearance and Optical ConsiderationsASTM PoliticsMr. Heater Tube Sez:PricingContact


Welcome to Standard Heater Tube, Inc.  You’ve come to the right place if you’re a smart scientist who is ready for the finest heater tube on the planet, because that’s what we make. Here you’ll find honest information leading to smart value and the finest test coupon available today. As established over the previous decade, we are the world’s leading producer of clean, chemically-inert heater tubes for the Jet Fuel Thermal Oxidation Stability Test (ASTM D3241).


Here you’ll find basic scientific information. There is an advantage to a tube having a good surface finish. A good finish makes for an easier task seeing and rating what is otherwise a difficult-to-see fuel deposit.

 Why Choose a Standard Heater Tube?

Only a Standard brand heater tube offers the benefit of our patented roller burnishing process. It is this process which makes our tube the standard throughout the industry.


Other tubes are produced using harsh abrasive finishing processes. These begin with a coarse or raw tube containing lathe marks or tooling marks. Abrasions are undesirable because they obscure from view the subtle deposits sometimes produced during the Jet Fuel Thermal Oxidation Test, ASTM D3241.


Competing manufacturers try to compensate for the presence of undesirable machine marks by abrading or “polishing” raw tubes. However, these harsh abrasive processes only add to the problem. By incorporating many thousands of supplemental abrasions and abrasive scratches onto the surface, these processes enhance the diffraction, diffusion, or scattering of light away from the eye of the deposit rater. The overall result is troublesome; a badly scratched or harshly abraded tube obscures deposit colors and makes deposits more difficult or even impossible to see. It should be clear to everyone that you cannot correctly rate a deposit which you cannot clearly see.


Standard Heater Tube, Inc. employs a non-abrasive finishing process for producing tubes. Our patented roller burnishing process altogether eliminates abrasions, microabrasions, gouges, scratches, as well as troubling tool markings left on the tube surface by our competitors. The result is a deposit image which we make easier to see, and thus easier to rate. A burnished tube doesn’t at all change the deposit color, amount of fuel-related deposits, or the chemistry or deposition mechanism of fuels. What it does do is to make the visualization and rating of fuel deposits easier.


Why is a roller burnished tube surface important?


Rating deposits which accumulate on a heater tube is a subjective but critical step in producing a fuel that can pass aviation fuel specifications. Currently, the rating is done visually at a relatively low 3X magnification under extreme lighting conditions. Often the deposits to be rated are the result of a fuel stain which is itself similar to a faint breath mark on a fine mirror. And, you can’t confidently rate a deposit like this when it is barely visible to begin with. That’s why a superior surface is important; it helps you see deposits better. A burnished surface, being a superior finish, let’s an observer see what’s really on the tube instead of using imagination or attempting to rate a coarse reflection of a deposit or image.


A Standard Heater Tube is a product you can use with confidence.



About Us

Although we are a small family business and a niche business, we happily lead the industry in heater tube technology and price. The Company is an S-Corporation, and the Heater Tube and Filter Kit is our primary product. 

We take pride that our product Heater Tube and Filter Kit is American made. We also offer two auxiliary American made items; a Pre-filter kit made, assembled, and sold by the Company for the ASTM D3241 test, and packages of fuel filter paper obtained through another American supplier The Company is registered through our government’s Central Contractor Registry.

For more than a decade we have produced the finest Heater Tube and Filter Kit available anywhere. Another supplier is part of a multi-national conglomerate operating as a monopoly tube supplier for approximately 40 years prior to competition from our Company. Under the Competition in Contracting Act of 1984, 41 U.S.C. 253 (a)(1)(A) et seq., government Contracting Officers must act affirmatively to obtain and safeguard competition; they cannot take a passive approach and remain in a noncompetitive position where they could reasonably take steps to enhance competition. Our company is not afraid of competition. In fact, we are the competition some larger companies fear.

ASTM Alternate Equipment Guidelines mandate encouragement, adoption and use of generic equipment once such equipment “has been made available and shown to be equivalent.” And, ASTM publishes Listing Guidelines for equipment supplied for its Standard Test Methods. By policy, the D02 Alternate Equipment Guidelines (found in the ASTM Publication Facts for Members) clearly state that ASTM doesn’t endorse, certify, or authenticate equipment or suppliers. ASTM is a voluntary consensus organization. Accordingly, all voluntary users of D3241 are free to employ a tube of their choice. Our business niche is providing to them a superior product and service at an aggressively competitive price.



 The Relevance of JFTOT Testing

A common but mistaken notion is that subtle fuel deposits are somehow catalytically induced by an inert aluminum heater tube surface. Basic chemistry teaches that aluminum cannot facilitate hydrocarbon oxidation. The suggestion that a heater tube supplier is criticially important to a Jet Fuel Thermal Oxidation Test (JFTOT) result is really a suggestion that the JFTOT test itself may be unreliable or even irrelevant.

That's because the Chemistry of a Jet Fuel Thermal Oxidation Test (JFTOT) is well known. Deposit formation, being a thermally initiated and propagated reaction mechanism, depends upon heat applied. Deposits also depend upon having a suitable oxygen concentration. It is established that in the absence of oxygen, deposit formation is nil. The result is that JFTOT fuel deterioration chemistry is dictated by heat and oxygen.

Well known and established principles of catalysis also reveal that flakes, granules, and powders would be catalytically superior to solid aluminum (like the coupon specified for this test) if catalysis was involved (it isn't). A Standard Heater Tube provides an inert solid aluminum surface upon which thermally-induced oxidation reactions can take place; all consistent with the chemical design principles for this aviation fuel test. Standard Heater Tubes are perfect for deposit visualization and rating. That's why we say our burnishing process has made competing production processes obsolete.


The Standard Heater Tube is protected through registration of U.S. Patent #7093481 issued by the U.S. Patent and Trademark Office. No other company produces or can offer such a patented Heater Tube and Filter Kit. Other tube features, including material composition, tube size, shape, and other mechanical properties are established by specification through ASTM D3241. Qinetiq, the research arm of the British Ministry of Defense, has already validated that mechanical and physical properties of Standard Heater Tubes comply with critical tube properties listed in D3241, including tube surface roughness.


The Problem of Performance Testing

For thirteen years, every Standard Heater Tube has met every ASTM tube specification. Make no mistake: our tubes have been exhaustively tested. Despite this, a residual concern for the problem of product performance testing arises from unrelated testing issues. These deserve consideration.

The issue of Performance Testing exists for two broad categories of users with very different needs: (1) those fully occupied with routine fuel performance testing, such as refinery labs, and (2) those involved in jet fuel research. Both groups have problems and issues with performance testing.

One reason is that, like all ASTM tests, the D3241 Jet Fuel Thermal Oxidation Test is empirically based or “trial and error” and a bit unscientific. Empiricism thrives in a world of un-science and even of unreality; it is a world without scientific basis. That fact tends to distress those who need a reliable pass-fail fuel stability test, where the “error” part of trial and error” is a concern or seems altogether unacceptable. The principal test result (determination of deposit color) is fundamentally subjective too. That is distressing to those engaged in scientific or statistically-based fuels research. Thus, almost all users look to performance testing, and to tube suppliers, to satisfy a hunger for statistics and for basic fuel testing information. The same test subjectivity and empirical nature of the test create difficult performance test design problems. Users of the test continue to seek solutions.

One solution is to use Standard Heater Tubes. The unique, patented application of a final tube finish guarantees that color bodies on or adjacent to the tube are readily visible for comparison and rating. In other words our tube is easier to read. (It is also easier to read the serial numbers on our tube).  In a Method where test subjectivity is known to be a serious issue, it makes sense to start with a tube which optimizes the clean, honest, image of fuel-related deposit colors that may form during a test. The finish and appearance of our tubes are highly consistent because they are burnished, and this provides an edge for users of our product.

Here are a few additional key limitations of the existing ASTM thermal oxidation test:


  The test result generated is a fuel deposit color. (This is what makes the test fundamentally subjective).


  There is no “standard fuel” or reference material for evaluating heater tubes or other Method materials, equipment, or supplies, and


  ASTM D3241 doesn’t specify a method for applying the final heater tube surface finish (which we assume would be specified as a tube property or critical test property if tube-finishing methodology was somehow critical to the test result).


  The array of color results are presented as a limited, non-continuous numerical display; one not easily interpreted by standard statistical methodologies.

Standard Heater Tubes have been exhaustively tested for suitability. Tube equivalence testing has been accomplished many times by many researchers at many companies, and even more tests are currently underway. A formal test program is available using procedures written into ASTM Research Report D02:RR-1550 for those who want to do their own testing.


Thus, despite intrinsic problems with performance testing, Tube Equivalence has been adequately demonstrated (1) through widespread commercial use over a thirteen-year period with flawless performance, (2) through a comprehensive equivalence program carried out prior to introduction and adoption of D02:RR-1550 into the Standard Test Method, (3) through testing conducted independently and privately by multiple users, and (4) through reliance on and strict adherence to ASTM policies, guidelines, and D3241 tube specifications and Critical Operating Characteristics (specifications which, incidentally, do not require specific tube performance or a performance test program). None of these testing issues have deterred general adoption and use of Standard Heater Tubes throughout the world. The U.S. government itself has purchased Standard Heater Tubes directly from The Company. Standard Heater Tubes are used in refinery and independent labs throughout the world; testing billions of gallons of jet fuel powering thousands of planes flying millions of miles around our planet.

If your technicians are having trouble or encounter difficulty making the subjective heater tube readings, try providing them with a tube which readily reveals the full, rich, colors of fuel-related deposits that form on the tube surface. After all, the determination of these deposit colors is the critical aspect of a fuel determination or rating.

By policy, ASTM doesn’t endorse or certify equipment. ASTM merely provides a courtesy listing of available tube sources in its Method. Listing is not a testing issue. Users know where to find us, and only the test user has “jurisdiction” to conduct tests necessary to determine or decide “fitness for service.”

So in summation, wise users resolve their performance testing problems by:

· Using product fully meeting all ASTM specifications,
· Which are demonstrably easier to read and rate,
· Whose solid positive test results were long ago delivered to ASTM (new final testing essentially complete), and
· Which enjoy more than a full decade of successful commercial use, and with 
· The complete absense of published negative findings by anyone, and
· Only tube users can ultimately determine fitness for service.

Contact us for a complete copy of currently available performance test results.


Appearance and Optical Considerations

The Jet Fuel Thermal Oxidation Test, ASTM D3241, calls for a visual examination and assessment of the color of a fuel-related deposit which is or which may be produced. Conventional thinking has held that the backdrop against which the assessment is made (a heater tube) may be important or even critical. Careful research calls such a belief into question.

The notion that tube appearance is "critical" is logically and demonstrably false. If that premise were true, the test would in fact be measuring something about a tube or its appearance or manufacturer. So for starters, that would not be much of a test. We think the test reveals something about fuels.

In addition, a tube supplier cannot influence fuel properties or the mechanism of deposit formation. Fuel degradation simply cannot, and does not, depend on an inert aluminum substrate . Remember that Aluminum is chemically inert. An effort to focus on heater tube manufacturer may be meant to detract from known test repeatability and reproducibility issues; problems which a new, easily-read tube (with a fine consistent finish) could begin to address and help resolve.

Experiment 1. Take a piece of colored foil paper and place it inside a visual tuberater (VTR), along with fresh new tubes of two manufacturers. Observe the result.

Now if the foil paper chosen is, say, red, and one tube appears more “red” than another, do we conclude that the tube surfaces are equally “red?” Of course not. The color is not coming from a tube. We conclude that one tube is easier to read colors with.

The evidence in this figure clearly shows that when using a competing product, you can’t rate what you cannot see. With our product, you can clearly see, and then clearly rate, the deposit color. The most powerful advantage attributed to Standard Heater Tubes is this ability to enhance the accurate determination of fuel deposit colors. Such a color determination is the undisputed and fundamental purpose of testing via ASTM D3241. 

Incidentally, if you had a “camera” rather than a person making the color determinations, and the camera showed one tube as revealing more “red” than another, would you conclude that a camera is more trustworthy than a real person to evaluate tube deposits? Moral: beware of anyone proposing use of a video camera to evaluate tubes, deposit colors, or fuels. The judgment of an objective scientist in this matter is both essential and indespensible.

Experiment 2: To prove out the equivalence of surfaces of various tube manufacturers, use the NBS-certified Surface Roughness Comparator available to top-notch machinists and metallurgists. This device, calibrated to National Bureau of Standards requirements, is based on an association between surface roughness and visual acuity, plus physical feel. It recognizes the reality that surface evaluation is fundamentally subjective. In short, you can “see” and you can “feel” different surface qualities (roughness) by comparing visually and tactually among surfaces. Using a set of such standards, it is easy to conclude that tubes of viable manufacturers are at or below a “2 microinch” finish (The tube surface finish required of a new tube by D-3241). That modern suppliers easily meet this requirement should surprise nobody.

Attempts to evaluate tube features by using surface profilometers have been made. British researchers compared tubes of the two equivalent manufacturers using surface profilometry, and more work is currently underway in the USA. However, a critical limitation of surface profilometry (applied to heater tube surfaces) is to only assess a surface in and along two-dimensions (length and height). The researcher confused actual surface quality with abstract surface-generated statistics. We need to use the correct tool to evaluate surface roughness. The Surface Comparitor is a tool for subjective roughness comparisons; it is one that is also standardized and calibrated for the purpose of making direct comparisons. The VTR is not.

Fuel-associated deposits are rated using an arbitrary color scale. A rating of 0 or 1 represents a clean tube surface with essentially no deposits. At the other end of the scale, a rating of >4 represents the darkest, heaviest fuel deposits possible. If you are lucky, your fuel will fall cleanly at one of these extremes and make for an easy rating job. This is the purposeful nature of a pass-fail test. However, some fuels are more difficult to categorize. For these more difficult fuels, optical considerations and a Standard brand heater tube become even more important.


In this situation a 3X magnification, as employed in the tuberater commonly used to evaluate fuel deposits, is often considered to be a crude, low, or poor magnification. Consequently lathe marks, (disguised by millions of supplemental abrasion marks which you also can't see at the poor 3X magnification), plus reflected images, dust, dirt, glare, and a variety of streaks and smudges can make viewing and rating the tube deposit --- if one is present at all --- more difficult. 


Also, other tube suppliers conventionally add millions of inherent scratch marks, gouges, harsh abrasions, and microabrasions to the tube. Some say this is tube “polishing.” But, the consequence of these scratches is to diffuse light away from the eye of the observer into countless randomly chosen directions. The result? It is harder to see, and to rate, nearby fuel-related deposits. Therefore, choose a tube source wisely. 


A person rating a borderline tube in this situation is like a city-dweller trying to evaluate bright stars on a cloudless night through the haze, dirt, and dust which accompany city living. That person may think the stars are not really very bright, and may not realize the problem isn’t with the stars; it’s a built-in characteristic of the environment.

Diffusion is a random scattering of available light such as occurs, for example, with a "frosted" light bulb. Diffraction, or the bending of light around a corner, is due to the wave property of light. In refraction,  the bending of light is at a distinct angle due to a change in medium density. Smart observers realize these phenomena as what they are: optical phenomena. They illustrate nothing at all about the surface of chemically inert aluminum coupons. Nor do such optical phenomena have anything at all to do with fuel chemistry or the mechanism of fuel deterioration.


Only a Standard Heater Tube allows you to avoid the confusion associated with optical effects. Where other heater tubes obscure the viewing of available deposits, Standard Heater Tubes provide a clean and honest image of real deposits.


Writing in the August 2005 issue of Advanced Material Processes (Why are Metals Shiny), Richard Chinn explains that “The light that strikes a metal is absorbed… but it can penetrate only a few hundred atoms into the surface, less than a single wavelength. The absorbed electromagnetic wave transfers its energy to the bonding electrons, which can jump up to a broad band of energy levels that also correspond to the full range of visible frequencies.” This means that what we “see” in the surface of a heater tube (a shiny finish) is really only excited energy being released as electrons change energy levels.

The appearance of a heater tube under light is no mystery, and there is nothing to be feared from a clean and inert tube surface.

In sum, what is seen in the appearance of a heater tube depends upon (1) lighting, (2) magnification, and (3) introduction of a deposit or color body into the viewing environment. The importance of these variables may differ naturally with subtle or intermediate-level deposits. 


ASTM Politics

As an American manufacturer, we support ASTM, and we believe the limit to our support is understandable: 

We make the finest ASTM-grade heater tubes. After many years of production and use, that fact presents a certain challenge to ASTM credibility. If the product works, and if it meets ASTM specs, then what is the problem? And the answer is, there is a credibility problem and a political bias problem, and no technical problem. We have pointed out the credibility problem to ASTM and requested redress. ASTM written policy is: to favor use of generic equipment in ASTM Standard Test Methods. ASTM stated policy clearly says equipment will get listed in a Method once it “becomes available” and is “shown to be equivalent.” In ASTM D3241, critical heater tube qualities are already given. We have no issues with any of that, and we would like to see these broad ASTM policies and specs fairly applied to our company and our primary product. Instead, we see bias. Our tubes are the finest. We offer statistical equivalence, a patented technology with easy-to-read tubes, and a very attractive price. That is the simple answer we give when asked repeatedly about ASTM testing or listing.  Listing is not an issue exactly because users do know where to find us.

Everyone hopes that the factors sustaining the current negative ASTM environment and politically-motivated bias can be quickly and rightly redirected. 


Mr. Heater Tube Sez:

As today I am king of the world, I proclaim for everyone a Heater Tube Bill of Rights:

Mr. Heater Tube claims that users have a right to see serialized tube numbers without any need for squinting or special glasses. King Tube would grant users the right to use either plain or numbered tubes, and proclaims that only Standard Heater Tube and D3241 provide for both types.

People have a right to the best price when purchasing tubes. 

King Heater Tube Sez that people, especially including ASTM people, are free to follow the ASTM written policy and not endorse or certify equipment or manufacturers. 

Mr. Heater Tube would grant all users the freedom to accept that aluminum tubing --- derived from a single mill --- really is chemically inert, and is inert regardless of manufacturer, and that fuel thermal decomposition chemistry or the mechanism of deposit formation are independent of the inert surface.

Mr. Heater Tube sez people are immediately free to give some or all business to their favorite Standard Heater Tube supplier, 

King Tube grants to tube users the freedom to think on their own, to avoid the herd instinct, to insist on rational scientific thought from their peers, and to lead the politicians among us (instead of blindly following them). Further freely granted is the right to dream, to be optimistic, hopeful, and positive about the opportunities (and heater tubes) surrounding them.

People are absolutely free to select a heater tube of their choice. This includes tubes which reveal or conceal adjacent coloration and are made to spec, Mr. Heater Tube, sez. People are free to test new ideas and new products from proven new suppliers, and to positively discard old ideas which no longer work.  

Mr. Heater Tube would grant to everyone the judgment to see that the ferocity of competing arguments is being derived from a fine product being offered at an even better price.

People have the right to an inexpensive, easy-to-read, clean, chemically-inert heater tube from a supplier of choice, sez Mr. Heater Tube.

On October 20, 2005 the U.S. Patent and Trademark Office provided to Standard Heater Tube, Inc. a Notice of Allowance for Ser. No. 10/986.706; Method For Roller Burnishing a Heater Tube.



One fact about our tubes is indisputable: The price is sensible! If you’ve been paying $432 or more for a case/pack/box of ten heater tubes, you’ll be pleased at our price of only $275 per case. Buy twenty cases and get them for $250. That’s a truly wonderful discount from others’ pricing which we happily give our customers.

Mention this web page and receive $25 per case off the regular price on your first order (maximum 5 cases).

We also carry pre-filter kits and "P-8" filter paper at affordable prices as convenience items for our customers.



P.O. 234 W. Bandera Rd.  # 350
Boerne, TX 78006

Email David Morris

phone 830-755-8695
fax 830-755-8697