Download Library


Date Download Description


Curtiss-Wright provides large bore snubbers that have been supplied to over 100 nuclear power plants worldwide. The snubber design has proven its reliability for over 30 years supporting steam generators, primary coolant pumps and other major components.

Enertech hydraulic snubbers are used to provide protection to major components during a seismic event while allowing for thermal expansion and contraction during normal plant operation. The use of Tefzel seals and zero maintenance control valves eliminates the need for additional test sampling.

Our field services include: snubber testing, rebuilding, retrofitting, trending and condition monitoring services, data acquisition and analysis for predictive maintenance. Enertech also provides OEM replacement snubbers and spare parts for Anker-Holth/McDowell Wellman, E-Systems, Paul-Munroe, and Phoenix & Enertech Hydraulic equipment.


Key Features and Benefits

Reliable Control Valve Tefzel seals that do not wear or need replacing
Maintenence Free Seals Seals are environmentally qualified for a 40 year design life and require no maintenance.
True Test-In-Place Verifies Operation without removal
Testan & TTIP Technology No pin removal required. Technology consists of isolating the control valves from the snubber body and testing it for lock up with no load transfer to plant equipment.

Principles of Operation

In plant normal operation mode, the snubber performs much of the same function as the seatbelt in a car. It permits slow, normal movement, but becomes rigid and holds the equipment when it senses sudden motion, such as seismic events or a line break.

Enertech hydraulic snubbers utilize a patented control valve which permits flow to either side of the piston head inside the cylinder during slow thermal movement. Sudden or rapid movement causes the valve to close. The key to Enertech's snubber reliability lies in the simplicity of its control valve design.

General Specifications

Load: Cyclical load testing using force levels of 90,000 lbs. or more
Shock Testing: Seismic equivalent shock testing involving a 2,000,000 Ib. load
Other Tests: Functional testing of lock-up, bleed rate, drag, breakaway and static spring rate
Quality Class: ASME Section III NPT and IEEE Qualified

Plant Design


Typical Plant Applications

  • Steam Generators
  • Primary Coolant Pumps
  • Other Major Components