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Section 706 of the Uniform Plumbing Code stipulates the requirements for changes in direction of drainage flow. Within this section are fitting pattern requirements for various changes in direction (horizontal to horizontal, vertical to horizontal, etc.). For horizontal to horizontal and vertical to horizontal changes of direction, a large radius fitting pattern is required. In cast iron systems, a 90° elbow with this fitting pattern is referred to as a “Short Sweep”. In ABS and PVC piping systems, this is generally referred to as a “Long Sweep” or “Long Turn” fitting.
You may have noticed manufacturers of ABS and PVC drainage fittings do not typically offer long turn elbows larger than 6 inches (or in some cases larger than 4 inches). This is because the standard that these fittings must comply with (ASTM D3311) does not go beyond 6 inches. Therefore any 90° ABS or PVC elbow larger than 6 inches cannot be listed to the proper standard and will not be compliant with UPC 301.2. If you find yourself needing to install ABS or PVC drainage systems larger than 6 inch, the only code compliant way to make a 90° horizontal to horizontal or vertical to horizontal change of direction is with (2) 45° elbows in series.
Please note, per UPC 710.7, the fitting patterns required for a specific change of direction in UPC 706 also apply to pumped waste and storm systems! When using pressure rated pipe, long sweep 90° fittings may not be available. These installations often require (2) 45° fittings connected in series to make a 90° change of direction compliant with UPC 710.7 and 706.0.
Recently, we've received questions about when we require new domestic water systems to be disinfected and when we do not. We only require potable water system disinfection in two instances. The first is when there is a new building with a new utility water service and the project has gone through Plan Review. The second is when the building water system is being substantially replaced (i.e. a re-pipe) and the project has gone through Plan Review. We do not require water system disinfection on projects that have not gone through Plan Review.
We often get a related question - is it ok to flush the system and get a lab test without going through the step of chlorination? The answer is no. All projects that require disinfection are required to comply with the full process of chlorination, flushing, and testing outlined in our disinfection policy.
Some examples of when is disinfection procedure is required (or not):
- New shell/core office building that has gone through Plan Review – Yes, disinfection required
- New tenant build-out within a shell/core building that has gone through Plan Review – No disinfection required
- Re-pipe of an existing apartment building that has gone through Plan Review – Yes, disinfection required
- Replacement of existing 2 story building with new 6 story building with new utility water meter – Yes, disinfection required
- Existing 4 story office building converted to hotel and reusing existing utility meter – disinfection may be required at discretion of Public Health.
If you have any doubt as to whether or not system disinfection is required for your project, please send an inquiry to planreviewinfo@kingcounty.gov before you call for final inspection to avoid any delays to your project.
Now that we have successfully updated our Occupancy and Use document, our next focus will be to update the Commercial Plumbing Design Guidance document. This document lists the information required to be submitted on a set of design documents for Plan Review along with specific advisory notes.
We have sent an open invitation to various design firms in the area to join a Policy Advisory Committee that will help review draft policy updates before they are published. If your firm is directly involved with the design and creation of plumbing design documents and would like to be a part of this advisory group, please sign up at this link. Please note, only (1) contact person per company may join the group. If you or another person in your firm has already joined, there is no need to sign up again.
We want your thoughts on how to implement new inspection requirements for insulation installations. Use this sign-up link to join our advisory group, which will meet virtually for the first time at 2pm on May 24, 2023. Please note: if you have already signed up, you do not need to submit this form again.
As a reminder, starting July 1, 2023, Public Health will begin inspecting insulation installations on plumbing systems. Since this is a new inspection policy, we are holding online meetings with stakeholders to discuss how to implement these inspections and enforce various Energy Code provisions. Our intent is to focus inspections primarily on two installation criteria: insulation thickness and insulation continuity.
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