During the past few cycles, there have been code changes submitted to the Plumbing, Mechanical, and Fuel Gas Code from the PMG Code Action Committee (PMGCAC).

The beauty of the PMGCAC is that it has the opportunity to research subject matters and discuss those in detail. Then it proposes changes to the respective codes. The long discussions by the PMGCAC were reduced to two minutes in support and one minute in rebuttal at the ICC Code Hearings in April in Columbus, Ohio. Imagine trying to explain intricate technical details of a code requirement in two minutes.

This cycle, PMGCAC had some success with its proposed code changes. Often times, if a subject matter impacts both residential and commercial plumbing, there will be a change to both the Plumbing Code and the Residential Code-Plumbing Section.

One such change to both codes involved the rating of compensating shower valves. The code change would require shower valves to be rated for the flow rate of the showerhead. While this modification sounds innocuous, it has become a serious problem with changes to showerheads trying to meet green or LEED requirements.

When a showerhead is rated for 1.5 gpm (or less) at 80 psi using a flow restrictor, that showerhead can flow as little as 0.75 gpm at 20 psi. While there is water savings, this low flow rate plays havoc with the shower valve. The code requires shower valves to be either pressure compensating or thermostatic mixing or a combination of both. When a manufacturer designs a compensating shower valve, it has to anticipate the flow rate through the shower valve. Reducing the flow rate can result in the compensating valve not providing the same level of protection to the end user. The reduced flow also will shorten the life of some of the internal components of the shower valve.

The Plumbing Code Committee seemed to understand the need for the change and voted to approve the proposal. The Residential Plumbing and Mechanical Committee recommended disapproval of the same code change to the Residential Code.

Down the drain

A plumbing inspector from Ohio submitted a change that would impact the design of toilet rooms having a floor drain. The change would require the floor to pitch 1/4 in. per foot to the floor drain. While the change addresses an issue that has long been a problem in the field, the concern voiced was that the pitch was too great. Most acknowledged that too often the floor drain is located at the highest point in the room serving no useful purpose. It was suggested that the change be modified during the public comment period to require the floor to be either level or graded to the floor drain.

There were a number of minor changes that will impact plumbing engineering design in commercial buildings. When there are multiple tenants in a building, a shutoff valve to the water supply would be required for each tenant space. The justification was that it is difficult for a tenant to find a main shutoff valve in the event of a leak. It also is difficult to shut off the water supply to the entire building when renovations are taking place in one tenant space. The code change was recommended for approval.

I submitted a change requiring the drain for a backflow preventer to be rated for the maximum discharge from the backflow preventer based on the manufacturer’s information sheet. All too often, you will find a 4-in. reduce pressure principle backflow preventer with a 2-in. floor drain in the room. The 2-in. floor drain won’t do much when a 4-in. valve is discharging at the full flow rate through the relief port. The change was recommended for approval.

Other discussed changes

In a previous column, I mentioned that a proposed change would remove galvanized steel pipe as an acceptable piping material for potable water systems. That code change was soundly defeated with extensive testimony in support of the use of galvanized steel pipe.

The water service to a hospital will require a tracer wire buried when nonmetallic pipe is installed based on a code change recommended for approval. UL added the appropriate standard for the tracer wire in an amendment to the change.

The change to require all connections to a building drain to enter on the vertical or 45° angle was soundly recommended for disapproval based on the lack of technical justification and the fact that building drains have been working well for more than 100 years.

There is a conflicting provision in the code dealing with cleanouts. In the definition, it appears a removable trap or removable fixture with an integral trap can serve as a cleanout. In the body of the code, it’s not so clear. A code change, recommended for approval, added the language to the cleanout section allowing a removable trap or removable fixture to serve as a cleanout.

The majority of the code changes in the Mechanical Code involved duct systems, plenums, ventilation and refrigeration. As has been typical for the last 25 years, there was once again a long discussion on what piping material can be exposed in a plenum and what fire test needs to be applied. PVC and ABS drainage and vent pipe still are prohibited from being located in a plenum. I cannot imagine a manufacturer loading up the pipe with fire-resistant chemicals just to allow the material to be exposed in a plenum. It is cheaper to box around any PVC or ABS pipe with gypsum rather than being exposed in a plenum.

The code changes to the hydronic section of the Mechanical Code mostly involved accepting new material standards or joining methods. ASHRAE did propose a change regarding Legionnaires’ disease, requiring compliance with ASHRAE 188 for all hydronic systems. That code change was recommended for disapproval. It was noted that the majority of hydronic systems are closed loop and therefore Legionnaires’ disease is not an issue. The other opposition centered around the standard being a risk assessment standard, not a design standard.

The deadline for submitting a public comment is July 16. The public comments will be discussed at the Annual ICC Conference scheduled for Oct. 24-31 in Richmond, Virginia.