Tuesday, May 10, 2016

On Hangers

This section deals pipe hangers.  Pipe supports are addressed in a different section.  One of the most common deficiencies with hangers is non-axial (side) loading.  Most, but not all, of these deficiencies appear to have occurred at the time of install.

Note, attics are ordinarily not subject to NFPA 25 inspection.

Hanger below may be non-axially loaded:

The photo below may show a hanger under non-axial load:

Below, the photo may show a hanger assembly under non-axial loads.  The tank below is an atmosphere water tank supplying a diesel driven fire pump:

Pipe hanger below may be have non-axial loads:

Below, the photo may show an unlisted hanger being utilized:

Photos below show hangers detached from structure.  Causes are many, in this case, vehicle imparted mechanical forces to overhead fire sprinkler piping.

Below, a hanger rod has detached from pipe clamp.

Another view:

Below, two (2) photographs reportedly showing clamp failure on heat exchanger cooling line for fire pump diesel engine driver.

Below, field modification of all threaded rod (ATR).

Below, three (3) photographs showing possible non-axial (side) loaded hangers.

Another non-axial loaded small hanger:

A possible example of a structurally deficient hanger due to non-axial loading:

Following image may show ATR disconnected from C-beam clamp. 

Image below may show c-beam clamp unattached from structural member.

Another example:

Close up:

C-beam clamp may not be attached to structure, clamp may have detached during or after pipe fracture.

The following two (2) photographs may show a design/install error.  Hanger rod may be under compressive loads.

The photograph below may show an unlisted hanger, the attachment point appears to be a non-structural element (frame arm of a sprinkler ahead).  Photo credit to A.T.

Photograph below may show another non-UL listed hanger.  There may be other violations of NFPA standards present.

The following photo may show all threaded rod under non-axial loads, the top support appears to be bent.  The same photo appears in the MPS section of this blog as an obstructed pull station.

Below, ring has not been attached to ATR:

Close up photo of above may show all threaded rod that is disconnected from hanger assembly:

Two (2) photos below may show a hanger requiring  adjustment:

Following photo may show a hanger assembly under non-axial loading:

Photo below may show a hanger with non-axial loading:

Photo below may show hanger with slight non-axial load damage:

Hanger requires adjustment below:

Following two (2) photos reportedly show possible movement by pipe and resulting damage to hanger:

Following three (3) photos show hanger possibly not fully engaged with structure:

Below, possibly another unlisted hanger device being utilized (this photo has been previously published by my friends at FPC Mag):

Below the photo shows possible evidence of a hanger detached from structure:

Two (2) photos below may show unlisted hanger:

Photo below (see red arrow) may show unlisted hanger assembly, assembly appears to have fracture:

Photo below may show missing all threaded rod for tear drop ring hanger:

Hanger below may show evidence of prior non-axial loading:

Below a photo shows a possibly field modified hanger rod:

The following photo may show a non-axial loaded hanger:

The following photo may show a hanger detached from structure:

The following photo may show a hanger that was subjected to non-axial loads, possibly as a result of field modification:

The following two (2) photos may show ATR subjected to non-axial loads:

The following shows remains of a pipe schedule fire sprinkler system which collapsed on to the floor of a school. The nature of the failure is unknown.  A working hypothesis is withdrawl of coach screw hangers caused by differential building movement resulting in system departing its installed location.:

Analysis of embedment depth of several failed attachments suggests inadequate embedment of some or all coach screws.

A link to a mass media news story surrounding the non-technical aspects of this collapse is below:


A photo below shows improper side-loaded hanger installation.  There is also missing signage.

Avenues Mall, Kuwait City, April 2017

Another view

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