After every IAPMO Technical Committee meeting discussing code changes, engineering colleagues always ask, “Does the union control the Uniform Plumbing Code (UPC) and the Uniform Mechanical Code (UMC)?”

The simple answer is, no — both codes are developed through the ANSI process.

Perhaps the better question is, “Does the union have a strong influence on the content of the UPC and UMC?” The answer would be absolutely. However, that does not make it bad. Union involvement during the UPC and UMC Technical Meetings is strong. The union representatives on the Technical Committee are intelligent and very forceful in their presentation of issues. However, there are also other forceful groups and representatives on the Technical Committee.

Code change debates

Many of the union’s positions during this cycle were good, with excellent health and safety provisions. Every so often, there is an ugly code change that has no rhyme or reason, except to the union. This occurred with a proposal to prohibit press connect fittings for refrigerant piping systems. Keep in mind that press connect fittings have been allowed in refrigerant piping systems for the past two editions of the code. 

Debate on press connect refrigerant fittings was nasty at times, with what appeared to be a vendetta not only against the fittings, but against UL 207, the standard that regulates refrigerant system components, including press connect fittings. Those supporting the prohibition of press connect fittings referenced older editions of UL 207. They failed to acknowledge that, like all standards, it had been updated, especially for the regulations of fittings.

The committee voted to approve the code change that would prohibit press connect fittings for refrigerant systems. The committee also voted to remove UL 207 as a mandatory referenced standard.

On the plumbing side, there seemed to be less contentious issues with code changes. There were a number of technical changes proposed to drainage pipe sizing and venting requirements. A change to increase the number of water closets on a 3-inch drain from five to six was approved.

I submitted a change to add the bathroom group fixture unit values, as published by Tom Konen, P.E., into the sizing table. The values currently appear in the appendix of the code. That change was rejected. While still in the code, it would simply require an engineered design to use the values as published in the appendix.

There were multiple changes proposed to circuit venting. The only change that received favorable consideration was a clarification that wall-mounted and back outlet water closets could be circuit vented provided they connected horizontally. 

A similar change that would have allowed any group of fixtures to be circuit vented was rejected. The reason provided was that circuit venting was designed for floor outlet fixtures.

There were other circuit venting proposals that attempted to limit the use of circuit venting. For example, one change would only allow lavatories to discharge as additional fixtures into a circuit vented branch. This would remove the common use of service sinks and drinking fountains discharging. This change was rejected. 

Another venting change proposed to move the single stack, also called the Philadelphia single stack, from the appendix to the body of the code. It is commonplace for sections in the engineered plumbing appendix to move into Chapter 9, which is venting. The committee rejected the change, stating that such a system needs to be designed by a registered design professional. That point is hard to argue.

The code change proposed by ASSE to allow the use of air admittance valves received very little discussion. There was an immediate motion to reject the change for the same reasons that have been used for the past 30 years. No one seemed energized to discuss the issue. The code change was quietly rejected.

With the movement toward greater acceptance of all gender toilet rooms, I proposed two code changes; one to correlate with the building code, the other to address the level of privacy. Since I served as the interim chair, I did not testify on either issue. 

The first change, to correlate with the building code, was rejected with the reason stating that this is already addressed in the building code. The problem with that statement is by not making the change, the requirements in the plumbing code conflict with the requirements of the building code. Typically, the building code will always win out. However, it would be better to have the two codes consistent.

On the privacy issue, the change was also rejected. However, the change had to be rejected since a standard was being referenced, and that standard has not yet been published. With the cycle being two years, the goal is to always complete a standard before the end of the code change cycle in order to have it referenced in the code.

Both the UPC and UMC had a series of code changes related to Legionella. The new appendix proposed to the UMC was overwhelmingly approved. A similar change was made to the appendix on Legionella currently in the UPC. That change received more discussion regarding the approach to take for prevention. Eventually, the change to the UPC was also approved.

The hydronic and geothermal sections in the UMC had a number of proposed changes to correlate the requirements with the Uniform Solar, Hydronics, and Geothermal Code. The geothermal requirements have always appeared in an appendix to the UMC. One of the last changes was to move the geothermal requirements into the body of the code as a new chapter. That change was approved.

Following the Technical Committee meetings, all code changes are voted on electronically by the committee. The electronic balloting requires a two-thirds majority to gain approval of the motions made during the Technical Committee meeting. The final votes will be published in the Report on Proposals, which will be available on the IAPMO website at the end of August.

The next phase is the comment period with comments due by January 2022.

The views expressed here are strictly those of the author and do not necessarily represent PM Engineer or BNP Media.