In the design of nuclear power plants many of the piping systems require protection against seismic events as dictated by ASME Section III.

In the early days, this seismic protection was achieved by installing hydraulic snubbers. There has been a shift in the industry away from hydraulic snubbers in favour of purely mechanical snubbers since these do not have any seals to rupture or fluid to leak.

My question is: "can a suitably sized Grinnell sway suppressor (Grinnell figure 301) be used instead of a mechanical snubber?". Imagine the followeing scenario wherein a seismic analysis is performed and CAESAR II reported a snubber lock-up restraint load of say 1500#. Would it be appropriate to install a Grinnell sway suppressor with a preload of 1500# acting at the pipe seismic support location? With the Grinnell sway suppressor the 1500# of restraint force would act the instant the pipe wanted to move away from the installed preloaded position. In effect, the sway suppressor is applying a 1500# restraining force against seismic movement.

I would like comment from this forum's readers on this subject.

Regards to all Patrick LaPointe P. E.