FAQ’s

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What is meant by the terminology, Reducing (or Oversize) and Non-Reducing (or Line-Size)?

Reducing and Non-Reducing is old terminology, in this case, used for types of jacketed piping insert flanges. You do not even really need to use them if you know the flange size x core size x jacket size. However, for history’s sake, and for those who are familiar with the terms; they can be defined as follows: Reducing and Non-Reducing refer to the nominal flange size relating to the core pipe size. For example, is you need an insert flange for a 3″ flange x 2″ core pipe x 3″ jacket pipe, the 3″ flange reduces to the 2″ core, therefore, this insert flange is Reducing. However, if you need an insert flange for a 2″ flange x 2″ core x 3″ jacket, the 2″ flange does not reduce to the 2″ core since it is the same size, thus, it would be considered Non-Reducing. You can see from this example how, if you know the nominal flange size x core pipe size x jacket pipe size, there is no need to refer to the insert flange as reducing or non-reducing. We also have specific product series that help to relieve this confusion. When in doubt, just use the series number. The benefit of our company being so experienced in insert flanges, also means we can sell

What is the best way to reference your flanges when I request a quotation?

First, you must determine if the flange is for a single or jacketed piping application. If you need an insert flange for single piping, either go to our Product Page for Single Piping and specify the size and series needed, or you can also reference the size, style, weight class, and material needed. For example, 2″, slip-on insert flange, for 150lbs., for a 316L pipe (which determines the insert material), and a carbon steel flange. If the insert flange is for jacketed piping, you can specify the series needed by going to our Product Page for Jacketed Pipe. Or you can specify the weight class, the flange size you will need x the core pipe size x the jacket pipe size you need; if you don’t know the series number you must state the style, either slip-on or buttweld for the core pipe, if it is slip-on we only need the jacket pipe schedule, if it is buttweld we will need the core and jacket pipe schedules; then just specify the material of your core pipe (which determines the insert material) and the material you need for your flange, which unless it is a special system would usually be carbon steel. If you have any questions, you can call us at 302-777-7464 and we can walk you though what you may need, or email us at sales@americaninsertflange.com with any related questions. It is well worth taking the short amount of time it takes to learn how to request a quote or how to order insert flanges! It is simple once you do it a few times and familiarize yourself with some of the terminology.
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Does American Insert Flange do any other type of custom flanges or machining?

Customization is our business at American Insert Flange. So besides our solid product line of insert flanges, we also thrive in being able to manufacture your custom flange design. Our sister companies, Specialty Flange and Fitting also can provide you with standard and customized flange options. Call anyone of the three companies and you will get the same high quality and successful result.

Is all of your material domestic?

There was a time when all of the material that came through our flange shop was domestic to the United States. However, in today’s competitive marketplace, we would almost be doing you a disservice not to give you an option of finding less expensive alternatives to some domestic material. Insert flanges are one of the few flanges left where most of them are still made from domestic material. However, on occasion, we do manufacture insert flanges out of foreign material. If you require that all material must be domestic, simply state this at the time of quotation. American Insert Flange prides ourselves in flexibility and doing our best to meet your pricing and quality needs.

What types of material can I order an insert flange in?

Almost any metal material that can be machined can be made into insert flanges. The most common material for an insert is domestic dual certified 304/304L and 316/316L, and for a flange it is domestic A-105 and 515/516 Grade 70 carbon steel. However, we also regularly make insert flanges out of Alloy 20, Duplex Alloys, Nickel Alloys such as various grades of Hastelloy (C276, C22), and Aluminum.

Do insert flanges conform to the requirements of ASME B31.3?

The answer to this question is YES. Process Piping, ASME B31.3, provides guidelines for the design of flanges which are not included as standards in Table 326.1 of this specification. These requirements are found in paragraph 304.5.1 of the code. This specifically says, “flanges may be designed in accordance with the Boiler Pressure Vessel Code, Section VIII, Div 1, Appendix 2 or Appendix Y, depending on whether the gasket OD is inside or outside the bolt circle. Flanges may be qualified by the requirements of paragraph 304.7.2. This paragraph applies when Appendix 2 or Appendix Y are not applicable and states that the design is to be based on calculations consistent with the design criteria on B31.3 and substantiated by one or more of the following:

  • a) Extensive & successful service experience under comparable conditions with similarly proportioned components.
  • b) Experimental stress analysis similar to that described in BPV Code, Section VIII, Div 2, Appendix 6.
  • c) Proof testing in accordance with ASME B16.9, MSS SP-97, or BPV Code Section VIII, Div 1, UG-101.
  • d)Detailed stress analysis such as finite element.” (passage taken from the ASME Code)

Insert flanges are based on ASME/ANSI B16.5 flanges, and contain the same ring-type elements. Insert flanges can be reliably designed to Appendix 2 of the BPV Code, Section VIII, Div 1. Insert flanges have passed the test of successful years of service since they have been used for over 75 years.

Why should I use an insert flange over the standard flanges that I am more familiar with?

There are many reasons why you should consider using insert flanges on some of your piping projects:

  • The two-piece make-up allows for the flange to rotate for easy alignment of the bolting holes. This allows our flanges to be fabricated faster.
  • The two-piece make-up also relieves joint stress that a single flange would have.
  • As stated above, insert flanges are not a commodity product. Therefore, they are made with tighter tolerances, and a more efficient quality system with little or no defects. Insert flanges also drastically reduce lead times when exotic alloy material is being used for a flange.
  • Insert flanges for jacketed piping are a unique flange to the industry. They are customized to meet the specific requirements of your core and jacket pipe schedules. This makes for a much cleaner and efficient assembly process. They also give you a better heat transfer through the flange. This can be huge in volatile piping environments and helps to decrease maintenance costs on piping lines.
  • Certain major chemical and plastics companies have used insert flanges for over 75 years. They have proven success in all types of piping systems. The companies who do not use them often do so because they simply do not know of the product. It only takes giving insert flanges a try on one project to convince many engineers and customers of this great product.
I have always thought only one company makes insert flanges, is there a patent or single company rights on this product?

You have probably thought that only one company makes insert flanges, because your particular company only used one supplier. However, there has never been a time in the history of insert flanges, where only one company has sold the product. There were always a few companies actively selling insert flanges on the market. An insert flange is a simple derivative of standard flanges. Therefore, in the same manner that a company cannot go and patent a standard socket weld or slip-on flange, an insert flange is non-patentable. This means that any company with the engineering knowledge and a firm grasp on flanges can manufacture insert flanges. Although insert flanges are stocked at American Insert Flange, they certainly are not a commodity item. You will not find Chinese or Indian imports of this product. This is in part, caused by the extreme nature of customization and detail that must go into manufacturing insert flanges. AIF knows how to stock insert flanges so that we can quickly turnaround your order. For example, we may stock insert flanges for jacketed piping only with a schedule 10 jacket, because we know that we can turn the insert into a schedule 40 jacket with a simple and quick machining operation. American Insert Flange is the new leader in insert flange technology. So if you are one of the companies out there who only buy from one supplier, please try our insert flange product today! We are an American company with “American Pride,” in everything we do.

What is the difference between your ASME Conforming (ASME Rated) and Conventional (Standard Thickness) lines of insert flanges?

ASME B16.5 and flange code is written for one-piece flanges. Obviously, an insert flange is a two-piece flange. AIF’s ASME Conforming line have thicknesses that are slightly more than that of the Conventional Line. The Conventional Line simply uses the standard flange thicknesses that a standard one-piece flange would use. The Conventional Line has existed much longer than the ASME Conforming one. However, we recommend now using our ASME Conforming Line unless you are replacing an old Conventional insert flange off of a pipeline. Therefore, for our ASME Conforming Line, engineering calculations were performed by American Insert Flange conforming to the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 to determine the minimum thickness of an insert flange so that they meet or exceed all pressure temperature ratings of the respective size and weight class, or ASME B16.5 MAWP. These calculations are based on using carbon steel (grades A-105 or SA515/516 Grade 70) for the flange and stainless steel (grades 304/304L and 316/316L) for the insert. The bolting is to SA-193-B7 and a spiral wound gasket material. If the material, bolting, or gasket is changed, the required dimensions of the insert flange could change. However, usually the thicknesses on our cut sheets will remain, and they change only in rare circumstances. This is how we make our ASME Conforming (sometimes called ASME Rated) Line.

What is an insert flange?

An insert flange is a two-piece flange, similar in concept to a lap-joint and stub-end flange, but of superior quality. It consists of an insert (usually made out of 316/316L or 304/304L), and a flange, or bolting ring (usually made out of A-105 or 515/516 Grade 70 carbon steel). These types of flanges have been used successfully in the PVF industry for over 75 years. American Insert Flange (AIF) makes a line of insert flanges for single piping applications as well a line for jacketed piping applications. See our Product Page to learn more about insert flanges and for more illustrations.

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