06182018Mon
Last updateFri, 15 Jun 2018 7pm

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The ASME Code Process for a Code Case: Non-Traditional Manufacturing Methods/Materials

What are ASME Code Cases and how do I get one? This article addresses the who, what, where, why, when and how of the ASME Boiler & Pressure Vessel Code (B&PVC) code cases relative to valves and other pressure equipment. The article will also review the code cases that are in-process or issued regarding powder metallurgy parts.

To understand the content and use of a code case, we must first discuss what a standard is: a set of technical definitions and guidelines. So, a code is a standard adopted by a government (that has the force of law) or a standard required by contract. The ASME B&PVC is called “code” for a variety of reasons, but some have joked that it is because it is very difficult to decipher the process.

What is a Code Case?

It is an exception or alternative to code rules that is non-mandatory to use, but available to all to employ. The code case also details very specific requirements for application. The vast majority of cases involve new materials. The use of the cases can be found on the ASME Manufacturer’s Data Report documentation.

A code case is a “try before you buy” product to introduce new materials, new design rules, new welding and NDE technologies, etc. Since code cases are issued on a quarterly basis to purchasers of the ASME Code Case book, it can be a way to get an idea into production on a much faster basis than waiting for the code book to be revised, which is currently done on a 2-year schedule. If revisions to a case are needed based on experience implementing the case, these revisions can also be done quarterly. Code cases are intended to be temporary and they are processed for incorporation or annulment after a period of time. However, more code cases are added than are incorporated – there are currently more than 400 B&PVC and more than 250 nuclear code cases waiting to be incorporated. Thus, code cases address an urgent industry need with the most current advancements for new technologies.

An analogy would be called “precedents” in the legal field. Historically, code cases were originally published as “Interpretation Cases”; the first one was published in 1916. They were then published as “Case Interpretations” starting in about 1956. Finally, they were published as “Code Cases” starting around 1974.

The Process

The processing of a code case can take as little as 2 months (highly unlikely) to years – most typical is about a year. One long-time Code Committee colleague once called the process a “multi-headed hydra”, meaning that there are many different committees which all have to participate in the process. Some of this work proceeds on auto-pilot and is rather easy to process through the system. Other parts of the project can be quite involved technically, administratively and politically. Some of the work is done offline through electronic balloting, but much of the work and negotiation is during the actual in-person quarterly meetings called “Code Weeks”. Many of the committees that are involved in the code case process meet concurrently, and the interested party or consultant or project manager may need to literally run from one meeting to another.

The process for submitting a new case or to revise an existing case are described in several places in the B&PVC itself. First, there is a general statement in the Foreword in every code section. Also, on page xxx (Roman numeral 30) of the ASME B&PVC, further detailed specifics are provided for the “Submittal of Technical Inquiries to the Boiler and Pressure Vessel Standards Committees”. If the inquiry is for a brand new material, a complete data set may have to be provided to the committee for analysis. The requirements for such data are described in Section II, Part D, Appendix 5.

Materials Assessed

There are code cases for ASME B&PVC (Sections I, II, III, IV, V, VIII-1/2/3, IX, X, XI & XII), the piping codes (e.g., B31.1, B31.3, B31.12) and for other ASME standards (e.g., B16.34). Advanced materials and materials manufacturing methods make up the vast majority of the quantity of all the non-nuclear code cases. There are many advanced metal alloys that go from the laboratory to industry through the code case route. Non-metallic materials have been initially introduced as code cases. Lately, advanced materials manufacturing methods are also gaining significant traction – specifically, HIP powder metal parts and sintered ceramic parts, and “additive manufacturing” processes (laser- or electron-beam-consolidated, etc.) have also been discussed for consideration. There are several code cases for ASME Sections III, IV and VIII-1 for polymers and several code cases for ASME Sections I and III and B31.1 for powder metals. There are also currently in development powder metal code cases for ASME Sections I and VIII-3 and B16.5/34/47, and a polymer for VIII-1. Ceramics are also in the process of becoming a code case and recently, the ASME Board on Pressure Technology formed a Project Team on the Evaluation of Additive Manufacturing for Pressure Retaining Equipment.

Use of the Code Case

There are specific rules within each ASME code book on how to use the code cases with regards to revisions that might occur over time. However, agreement is key to when to use a code case. There may be a need to obtain the purchaser’s approval of the use of a particular code case. Also, the jurisdictions (governmental bodies) may have laws and/or regulations regarding the use of code cases. It would be a good idea to research this first before building the equipment.

Code cases can be obtained by purchasing hard-copy or electronic versions of the actual book that is published by ASME or through their resellers. There is also a database provided by ASME that has a listing of many of the code cases, some with pdf copies of the case itself.

Hopefully, this article has quelled any fears regarding code cases and explained how valuable they are to keeping the industry up to date. The key to establishing new code cases is to be prepared and participate in the process that qualifies them.

This email address is being protected from spambots. You need JavaScript enabled to view it., P.E., BSME, MSMet is principal engineer at HSB Global Standards and is a member of the ASME Standards Committees on Materials and Pressure Vessels. He is chair of the subgroup on Materials for Pressure Vessels and a member of ASM, ASTM and NACE.

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