38/Plumbing Engineer October 2020

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ngineers are often asked to review the designs of existing fire sprinkler systems for a variety of rea- sons: a change to the facility, its occupancy or ten- ancy; a due diligence review for a prospective purchaser of the property; or an upgrade desired by the owner or mandated by local authorities or insurance interests. Reviewing the design of existing sprinkler systems is now more complex than ever due to the almost constant evolution of design criteria incorporated into applicable standards, but determining the adequacy of an existing system can be accomplished by following a few simple steps. The verification of appropriate design begins with a comprehensive examination of original assumptions. Design drawings, design basis reports and as-built or record drawings are good sources of information for conducting a review, if available. Even with these documents, however, a limited site visit to verify that the installation is consistent with the documents will provide further verification. If the records are not available, a more comprehensive site visit is needed to determine the design of the installation with a clean-sheet approach and then conduct the review. Over time, changes to the building, contents, opera- tions and water supply often occur, affecting the adequa- cy of the existing fire sprinkler system. A conversation with the owner or operator of the facility can reveal if there were recent changes or additions to the building, its operations and contents since the time of the original system installation. Engineers should carefully note the operations and contents of the building and determine the hazard classi- fication of the building as defined by NFPA 13, Standard for the Installation of Sprinkler Systems. Subtle changes in building contents, such as the packaging of finished goods in storage, can affect the hazard classification and have a significant effect on the adequacy of sprinkler protection. Other subtle changes that may not be immediately apparent on a site visit include the method of storage, e.g., from solid pile to rack storage; changes to packag- ing, e.g., from cardboard within cardboard, to foam plas- tic within cardboard; changes to products resulting in a higher plastic content; changes from nonencapsulated storage to encapsulated storage; changes from wood pallets to plastic pallets; and changes in operations from manufacturing to a combination of manufacturing and storage. The operations and storage details should be docu- mented and then reviewed per the latest versions of NFPA 13 and applicable insurance criteria. Verify the installed pipe sizes, sprinkler spacing and sprinkler model. This can be accomplished by a review of the as-built drawings and field verification. A clue to verifying the installed sprinkler model can often be found

Existing Systems: Reviewing the Design

FPE Corner

By Carl F. Baldassarra, PE, SFPE

Changes to the building, contents, operations and water supply often occur, affecting the adequacy of the existing fire sprinkler system.

SFPE News SFPE is excited to invite you to its first virtual annual conference, which will be delivered online Nov. 9-11. The conference program, including speak- ers and registration, will be available at www.sfpe.org/ ACVirtual2020 in September. The first day of the conference will be complimen- tary to SFPE members. The remaining two days will feature keynote presentations and panel discussions by industry executives, technical sessions examining the latest industry trends, access to future perspective and premium webinars that will explore technical topics in greater detail, and virtual happy hours for our special interest groups and Women in Engineering program. Please mark your calendars for Nov. 9-11 and be on the lookout for future announcements. We look forward to sharing an exceptional program that will be accessible to all for the first time and want to thank our Conference Program Committee, co-chaired by Michael Crowley and Katie Pothier.

Inspection reports by state and local authorities should be reviewed to determine if any deficiencies in system design or maintenance have been cited. Photo credit: iStock.com/work- hardphotos