David Dexter: Plumbing Talking Points

Backfill and bedding

Thu, 13 Feb 2025 00:00:00 -0500

Installing underground plumbing requires removing existing materials to place the piping system. However, this effort moves the designer/engineer into territory not typically part of their knowledge base: “Backfill and Bedding.” Additionally, the requirements will likely differ depending on the interior, exterior, or public right-of-way location. Code sections, rules, and engineering standards will likely address each area.

Bringing modern plumbing into historical buildings

Tue, 10 Dec 2024 00:00:00 -0500

Join me as I explore the journey of plumbing from ancient practices to modern systems, all while uncovering the challenges of integrating sanitation into historic structures like Edinburgh Castle.

Gaseous regulators, what are they?

Mon, 14 Oct 2024 00:00:00 -0400

As design engineers, we frequently use systems requiring pressure regulation. A regulator, as defined by the ASPE Plumbing Dictionary, reduces variable inlet pressure to a stable outlet pressure under changing flow conditions. It maintains a uniform gas pressure lower than the supply pressure. Essentially, a regulator ensures consistent downstream pressure from a variable upstream pressure.

Plumbing application and implementation varies around the world

Wed, 05 Jun 2024 00:00:00 -0400

Plumbing involves providing clean water, managing wastewater, and ensuring water quality for safe use. It also includes handling various other systems such as gas distribution, drainage, and laboratory systems.

Identifying back-feed potentials within domestic hot water risers

Thu, 04 Apr 2024 00:00:00 -0400

The author reflects on a recent trip to South America and Antarctica and discusses the topic of identifying back-feed potentials within domestic hot water risers, drawing from an article by Miles Ryan, PE, about typical issues found in high-rise residential buildings.

Reducing the potential for pathogenic growth in showerheads

Tue, 06 Feb 2024 00:00:00 -0500

Introducing Safe Shower's new showerhead that minimizes the growth of biofilm and pathogens like Legionella. The showerhead circulates disinfectants like chlorine or UV water and uses UVC LED disinfectant approach that generates electricity using a tiny turbine.

Venting vertical offsets in sanitary drainage piping

Mon, 04 Dec 2023 00:00:00 -0500

What do the 3-model codes, UPC (Uniform Plumbing Code), IPC (International Plumbing Code) and NSPC (National Standard Plumbing Code), have to say on the subject?

Where does a sanitary plumbing system begin and end?

Tue, 03 Oct 2023 00:00:00 -0400

As design professionals, our first and primary obligation is the protection of public health, safety and welfare above all other concerns.

Obligations to the engineering profession

Mon, 07 Aug 2023 00:00:00 -0400

Regardless of our position in an organization or profession, we all have obligations and responsibilities to the career that we have chosen.

David Dexter: Circulation in plumbing system design

Mon, 05 Jun 2023 00:00:00 -0400

Mechanical engineering is an integral part of both HVACR (Heating, Ventilating, Air-Conditioning and Refrigeration) and plumbing. While both disciplines utilize the same science and engineering principles, their application diverges depending on the system under consideration. A prime example of this is the “wet” piping system that moves water through the piping network.

David Dexter: Fitting Selection and proper flow

Wed, 05 Apr 2023 00:00:00 -0400

Codes and standards are intended to provide a minimum level of protection for the public’s health, safety and welfare. And, generally, these documents accomplish that intended purpose in the urban/metropolitan areas of the United States. However, that may not be accurate when one gets into the rural or more isolated areas of the country.

David Dexter: Plumbing systems around the world

Mon, 06 Feb 2023 00:00:00 -0500

Codes and standards are intended to provide a minimum level of protection of the public’s health, safety and welfare. And, generally, these documents accomplish that intended purpose in the urban/metropolitan areas of the United States. However, that may not be accurate when one gets into the rural or more isolated areas of the country.

David Dexter: The ANSI process versus governmental process

Wed, 07 Dec 2022 00:00:00 -0500

“Governmental members” may desire a public perception of having “no vested financial interest in” the development process. But there is no requirement or mandate for them to be transparent in avoiding conflicts of interest.

David Dexter: Who designs the perimeter and foundation drainage system?

Thu, 06 Oct 2022 00:00:00 -0400

Recently, the question was asked on ASPE’s Open Forum “Foundation drain pipe — plumbing responsible? Or only between civil and structural?” As originally posted, the designer did not have a Geotech report. But the structural consultant did show the piping around the top of the elevator footing and the perimeter footing for the foundation in their details.

Devid Dexter: The merits of regulations

Fri, 05 Aug 2022 00:00:00 -0400

Regulations have been a big topic over the past several years. Politicians, trying to make a public name, have been pushing for the reduction of regulations. They like to claim that these regulations are an impediment to economic growth and entry into certain professions. While some of this may have merit, one needs to “not throw out the baby with the bath water.”

David Dexter: Running horizontal drains

Wed, 08 Jun 2022 00:00:00 -0400

Let us get down in the dirt, or at least “backfill.” A recent discussion on ASPE Connect’s “Open Forum” was entitled “Minimum Pipe Cover when Calculating Invert Under Building Slab for PVC Sanitary.”

David Dexter: Digging deeper into thermal expansion

Thu, 07 Apr 2022 00:00:00 -0400

Recently, I wrote about plumbing pipe thermal expansion and expansion fittings. Based upon feedback from some in the design community, there seems to be a feeling that more design professionals within the consulting industry need to have a better foundation to enhance their understanding of the topic.

David Dexter: Understanding thermal expansion and expansion fittings

Tue, 08 Feb 2022 00:00:00 -0500

Recently, there was a discussion on the ASPE Open Forum regarding, “Plumbing Pipe Thermal Expansion and Expansion Fitting.” Generally, this topic would be found within your specifications under Section 22 05 16, “Expansion Fittings and Loops for Plumbing Piping;” this topic is under-discussed, and in many cases, poorly understood by many designers and engineers.