SECTION                                                             SUBJECT


1.0                                         GENERAL SUMMARY


2.0                                         SCOPE OF SUPPLY


3.0                                         DESIGN HIGHLIGHTS


4.0                                         MANUFACTURING FACILITIES & EXPERIENCE


5.0                                         ENIDINE ENGINEERING


6.0                                         PERFORMANCE TESTING


7.0                                         QUALITY ASSURANCE


8.0                                         TECHNICAL DESCRIPTION OF THE DAMPER


9.0                                         ENIDINE SEISMIC TEAM PROFILE


10.0                                      KEY PROJECT HISTORY LOG










Over a decade ago, ENIDINE designed and manufactured our first viscous dampers for nuclear seismic applications.  ENIDINE has a long and successful history of providing energy absorption devices for a wide variety of critical applications.  The ENIDINE philosophy is to work closely with our clients in the design, manufacture and support of our components long after installation.  ENIDINE has been a leader in the energy absorption business for over 35 years.  As part of International Motion Control Inc. (IMC), a global organization offering a broad range of automation and motion control technologies, ENIDINE has the engineering expertise and manufacturing capabilities to provide dampers of up to 1,000 Kip.


ENIDINE has optimized the damper design to meet three design criteria goals:


a.            Meet all technical performance outlined by the Structural Specification

b.            Provide a damper design with a minimum useful life of 50 years

c.            Provide a maintenance-free damper design to the Owner




The project specific Scope of Supply is defined by the ENIDINE Quotation.  Refer to the current quotation for listed items, prices, deliveries, and other terms.


Items that are not part of our Scope of Supply as the Damper Manufacturer include, for example, the structural design analysis & drawings, the structural steel work, the installation and erection of the dampers in the field.


As the Damper Manufacturer, the following items may be assigned as part of our Scope of Supply (refer to the current quotation for listed items):


a.            Viscous Dampers as defined by the Design Specification

b.            Damper Pins for end connection to brackets or structural members

c.            Damper Brackets for field or shop welding to the structural bracing

d.            Functional Performance Testing of the damper

e.            Certified QA/CMTR/Testing Data Package

f.             Third Party Witness subcontract for testing

g.            Technical Site Support

h.            Shipment of dampers to site (FOB SITE)

i.             Applied local and state taxes






·         The damper design utilizes an annular orifice technology that has no moving parts and meets the Damping Constitutive Law:


                                                                              F             =             C Va


F             =             Damper Resistive Force (Kips)

C            =             Damping Coefficient (Kips/[ips]a)

V            =             Velocity (ips)

a            =             Velocity exponent (dimensionless)


·         ENIDINE’s orifice design compensates for temperature variations from 30oF to 120oF.  Our orifice provides a simple method of achieving the constitutive law desired without requiring any moving mechanical parts other than the piston head moving through the hydraulic fluid.  This prevents the possibility of fatigued, misaligned, jammed or incorrectly assembled multiple-piece orifices from affecting the performance of the damper at critical times.


·         The damper has a minimum number of moving parts and features simplicity as its overriding design criteria.  The damper can be completely maintained by any qualified hydraulic mechanic with the information provided by ENIDINE.


·         The damper utilizes a spring-loaded reservoir that provides a positive pressure throughout the vessel.  This pressure will activate the seals and prevent moisture and contamination from entering the fluid.  The reservoir requires no gas or high-pressure fluid charge to maintain its functionality.


·         The double-rod design concept allows the damping in extension and compression to be identical without requiring additional components.  This design also minimizes reservoir requirements.  The double-rod design creates a much more stable design under lateral load conditions, such as those found during seismic events.


·         The damper can be fitted with an externally visible Checked Fill Port for initial fluid filling and field inspection.


·         All damper surfaces are designed of stainless steel or epoxy painted alloy steel for corrosion resistance.


·         The damper is designed with an external Protective Sleeve for the piston rod.  This sleeve protects the piston rod from both debris and side loads.


·         ENIDINE also provides a single-rod design for installations that have absolute space constraints and limitations.


·         The final project-specific damper design shall meet the technical requirements set forth in the Contract Damper Specification.




·         Headquartered in Orchard Park , New York , ENIDINE was established in 1966 to design, manufacture and market Energy Absorption and Vibration Isolation products worldwide.

ENIDINE is a leader in developing state of the art technology in the field of fluid controlled energy dissipation devices.


·         ENIDINE has always recognized the importance of having a global presence.  From the beginning, ENIDINE exported its products through various licensing and distribution agreements.  In 1976, ENIDINE continued to expand its international presence with a European headquarters in Germany , Pacific headquarters in Japan , and various subsidiaries and affiliates in the United Kingdom , Switzerland , Spain and Mexico .


·         In 1989, ENIDINE West was established in Irvine , California to improve communications and support to customers located in the western states.  ENIDINE West has also served as our Seismic Program office.


·         In 1995 International Motion Control Inc. (IMC) was established as a holding company to oversee ENIDINE and the growing number of companies and subsidiaries that had become a part of ENIDINE.  A few of the other companies that have joined IMC include Midland Pneumatics, Compact Automation Products Inc., CMC (Cleveland Motion Controls Inc.), and Motion Science Inc.


·         Today, these companies are working together sharing technology, engineering expertise, manufacturing facilities and their extensive distribution network.  IMC has a combined work force of 800 employees and annual sales in excess of $100 million.


·         ENIDINE expertise in energy dissipation is a result of designing and building fluid filled dampers and shock absorbers for over 35 years.  In the last three years alone, ENIDINE has built and delivered over 1 million shock absorbers and dampers of varying sizes.  One third of those products were special designs, engineered for customer specific applications.


·         ENIDINE has developed an extensive knowledge base of various methods of orifice design, interface package design and custom assembly of energy dissipation products.  ENIDINE is familiar with the numerous trade-off characteristics of product design related to performance, product cost, reliability, longevity, complexity and maintainability.


·         The prototype and production viscous dampers will be manufactured and assembled utilizing the combined efforts of the ENIDINE machine shop, which is an internal prototype machining and production facility, in conjunction with one of our manufacturing vendors that specializes in large bore cylinders.  The size and complexity of the fluid viscous dampers require machining capabilities not resident in all manufacturing or fabricating facilities, due to the cost of capital investment.




·         In order to serve the wide variety of products represented by our diverse customer base, ENIDINE Engineering is divided into three groups, Research and Development Group, Aerospace/Defense Group, and Industrial Group.


·         The Research and Development Group is charged with developing new technologies that will ensure that ENIDINE provides the best engineering solutions in shock and vibration technology worldwide.  This group is responsible for expanding our knowledge in orifice technologies, as well as developing and expanding our lines of seismic and shock isolation products, wire rope and elastomeric mounts.


·         The Aerospace/Defense Group provides the engineering support for applications that cannot be met by standard products.  This group has expertise in developing products for use by military and aerospace customers to fulfill their demanding requirements, as well as, developing special products for commercial applications.


·         The Industrial Group has a large selection of standard shock and vibration products designed to meet the needs of most applications.  ENIDINE will frequently solve complex applications with a mixture of standard components from our Engineering Libraries.  ENIDINE currently has over 14,000 active component parts to select from during the design process.


·         The ENIDINE Engineering groups have available the following computerized design and analysis capabilities.


a.            2-D CAD Software

·         Anvil1000


b.            3-D CAD Software

·         SolidWorks


c.            Finite Element & Dynamic Software

·         Cosmos 6 DOF

·         DADS Dynamic Modeler

·         SAP-2000


d.            Mathematical Modeling

·         MathCAD

·         MATLAB




·         ENIDINE recommends that the dampers be mounted in a dynamic hydraulic test bench and performance tested with a sinusoidal wave pattern.  The closed-loop controlled displacement input signal shall follow a sine wave pattern with a data acquisition rate of

at least 50 Hz.


·         Each Prototype and Production Damper will be tested at 70° F at 50% and 100% of the rated velocity.  In addition, one of each type of Prototype Damper will be tested at 30° F

at 50% and 100% of the rated velocity.  The Structural Engineer of record must define the sinusoidal peak-to-peak displacement based on the following constitutive laws:


                                Displacement                    =                + D·sin (2π·ƒ·t)                     =             input signal

                                Velocity = + 2π·ƒ·t·D·cos (2π·ƒ·t)=   + V·cos (2π·ƒ·t)

                                Force                                  =                + C·Vα                                    =             output response


·         The Structural Engineer should also consider the overall energy absorption that will occur during the 30 to 45 second MCE Earthquake.  This is the amount of energy, with a safety factor, that the damper must absorb during the event.


·         The resulting sinusoidal damping force, velocity and displacement, as a function of time, should be recorded.  The test results shall be plotted as wave patterns, as a function of time and as a force-displacement hysteretic loop.  The force-displacement data of the first hysteretic loop shall be mathematically reduced to identify the damper’s dissipative energy efficiency.


·         All testing will be conducted in-house at ENIDINE on our fully programmable dynamic test bench, which was specifically designed and commissioned for seismic and military prototype and production damper testing.




·         As an industry leader in the field of energy absorption and vibration isolation, ENIDINE satisfies the most stringent quality assurance requirements of our customers through a

fully implemented Quality Management System.


·         The foundation of the ENIDINE quality system was built from many years of providing highly engineered products to the U.S. government, as a result we are fully compliant

 with the requirements of MIL-Q-9858A.


·         In order to satisfy the quality needs of our customers around the world, ENIDINE is certified to the quality system requirements of the International Standards Organization, ISO-9001 and is recognized by national accreditation boards domestically and abroad.


·         ENIDINE’s approach to quality assurance begins with the QA Department serving as an active participant in product design development and product qualification.  ENIDINE presently has established Quality Assurance Programs, utilizing:


Ø                   ISO-9001


Ø                   ANSI/ASQ Q91


Ø                   MIL-Q-9858A


Ø                   MIL-I-45208A


Ø                   Boeing DI-9000


Ø                   FAA Regulation 21, Subpart K







ENIDINE Quality Control Plan


Page 1 of 1

1) Plan Number:




2) Customer:

Seismic Project



3) ENIDINE Part Number:




4) Description:

200 Kip x  8” Stroke Std Viscous Dampers

Design, Manufacture & Test Viscous Dampers



5) ENIDINE Drawing No:




6) Reference Documents:

Customer SpecificationSection 13080



7) Reference Sections:

Reference sections



8)  General:

This quality plan is meant to supplement ENIDINE drawings and the Customer specification.  This plan will provide information indicating the quality framework to be followed during design and manufacturing of this project.



9) Applicable Specifications

     and Standards

Customer Spec




ENIDINE’s QA System (compliant with ISO-9001 (Certified by BVQi)








ASME BPV Code – ASME Boiler & Pressure Vessel Codes




AWS D1.1 – AWS Structural Welding Code - Steel




MIL-C-26074 – Coating, Electroless Nickel Requirements




QQ-C-320 – Plating, Specifications for Industrial Chrome



10) Certifications & Traceability:

Ø       Material Heat Lot Traceability Required

Ø       Certified Material Test Reports required referenced structural components – see ENIDINE drawing

Ø       The drawing of each component part will specify where this requirement is necessary.  If CMTR are not called out on the component part drawing, the vendor will maintain a copy of the material COC from their supplier certifying that the supplied material meets referenced material specification.



11) Marking & Identification:

Ø       Each serialized seismic damper shall have its own data package, unless the parts all come from the same heat lot.  If all component parts come from the same heat lot, the package will identify the applicable S/N's that the data package applies to.

Ø       Component parts requiring traceability shall be identified through all stages of production.

Ø       Each seismic damper is to be serialized and marked in accordance with Customer Spec. 13080.



12) Testing:

A.   Prototype Acceptance Testing will be in accordance with Customer Acceptance Test Plan.




B.   Prototype Damper Testing Plan prepared in accordance with 13080 (PROTOTYPE DAMPER TESTS).




C.       QC Test Plan prepared in accordance with 13080





D. A QC Test Report shall be prepared for each damper in accordance with contractual requirements.



13) Cleaning & Painting:

TBD - As required by Contract and ENIDINE Drawings



14) Certifications & Reports:

Certificate of compliance, certified material test reports (CMTR's), QC Test Reports and Certification of special processes.



15) Approvals:







·         The damper is a double acting, hydraulic cylinder device that incorporates a through rod design.


·         The damper utilizes a thermally compensated annular orifice technology that contains no moving parts.  This orifice system meets the constitutive law requirements of the damper specifications.


·         The damper design is a combination of stainless steel and carbon steel components.  All carbon steel components are epoxy painted for corrosion protection.


·         The damper design can withstand a continuous 2g-side load.  In the primary load direction, the damper will be designed with the minimum safety factors imposed by the customer’s specification.  At a minimum, the damper will be designed with a safety factor of 1.5 on yield and 2.0 on tensile failure.


·         The damper has a spring-energized piston-type reservoir.  This reservoir acts as a thermal compensation device designed to maintain a near constant static pressure in the damper.  The spring-energized reservoir allows the fluid volume in the unit to expand and contract, as a result of ambient temperature changes, with minimal variation in overall system pressure.


·         The hydraulic fluid is silicone oil (dimethyl polysiloxane class).  This type of hydraulic fluid is selected for its combination of properties:

Ø       Low change in viscosity as a function of temperature

Ø       Excellent shear stability and high resistance to mechanical shear

Ø       Excellent heat conductivity and is constant over a wide temperature range

Ø       Non corrosive and chemically inert

Ø       Self-extinguishing flame-point at 700oF

Ø       Very low toxicity and presents no environmental concerns


·         The damper attaches to the structure by means of spherical bearings, which are designed into each end of the unit.  These spherical bearings allow for 6 degree of free rotation and articulation.  The damper mounts via mounting pin assemblies.  These pins pass through the spherical bearings and the structure’s brackets and create a pin-pin connection.  This places the damper in a pure axial loading condition (e.g. X-loading, Y-free, Z-free, and the three rotational directions – free).


·         The damper should be installed at or near the mid-stroke position.  To ease installation of the dampers, the units have been designed with a minimum of 1/2" of additional stroke length.  This additional stroke length will allow the unit to be adjusted in the field to mate up with the structural brackets that will support the damper.


·         The damper is designed for a thirty-five year life with little or no maintenance.  ENIDINE recommends that the dampers be inspected at regular intervals to ensure their readiness for use.  The inspectors should look for any signs of hydraulic fluid leakage, and bent, distorted, cut, dented, or abraded components of the damper.

·         An Installation, Operation and Maintenance Manual (IOM) will be provided with the damper.  The operation of a damper is passive, once properly installed the unit does not require active operational elements, e.g. power, hydraulics, air or electricity.  The IOM Manual is a critical document that identifies the required methods for installation and maintenance.


·         The internal configuration of the damper can be summarized, as follows:


Ø       The Piston Rod extends through the damper primary Cylinder.

Ø       The Piston Rod extends into the secondary Cylinder.

Ø       The Piston Rod is sealed at each end to prevent leakage via two dynamic seals.

Ø       The Piston Rod is protected from external damage with a Structural Sleeve.

Ø       The Piston Rod is manufactured from 17-4PH Stainless Steel.

Ø       The Piston Rod is connected to a Piston Head.

Ø       The Piston Head separates the primary Cylinder into two hydraulic chambers.

Ø       The Piston Head connects the two chambers via the damping Orifice.

Ø       The Reservoir consists of a bleed orifice, a check valve, and a spring-loaded piston.

Ø       The damper body is made up of a primary Cylinder and a secondary Cylinder.

Ø       The secondary Cylinder is where the Reservoir Assembly resides.

Ø       The end of the Piston Rod has a Clevis for mounting purposes.

Ø       The end of the secondary Cylinder has a Clevis for mounting purposes.

Ø       The Clevis Ends are where the Spherical Bearings are found.

Ø       The damper is fitted with a pressurized Fill Port.


·         The damper operates in a similar fashion for both the tension and compression mode.  For example, during the extension mode a tensile (extending) force is applied to the spherical bearings.  This force tends to extend the damper and thus move the piston rod and piston head assemblies.  This increases the fluid pressure in the tension side of the primary cylinder (tension chamber), which drives fluid through the orifice.  This fluid travels to the low-pressure side of the piston head (e.g. the compression chamber).  The flow of fluid from the high-pressure side through the orifice to the low-pressure side creates the actual damping forces.  The seismic energy is converted into thermal energy by the viscous shearing of silicone fluid as it passes through the orifice.



















·         Mike Siino, P.E., Vice President & General Manager of Engineered Products, which includes Enidine Seismic and Enidine Aerospace will oversee the technical aspects of the program, including engineering, material purchasing, product estimating, manufacturing, quality control and testing.  Mike has 15 + years of senior management and project engineering in defense, seismic and construction field.  MS & BS ME, University of California Davis, MBA CSU Fullerton, Licensed Mechanical Engineer in the states of California and Washington.


·         Mary Kerns, Seismic Program Manager, will be responsible for the overall program management including sales, marketing, scheduling, budgeting, and control of project activities.  Mary has 20 + years of industrial program management, technology development and marketing experience.  M. Ed. & BA, University of Buffalo.


·         Brian Bucholtz, Senior Seismic Project Engineer, will be responsible for the design drafting and structural calculations of the fluid viscous dampers.  Brian has 25 years mechanical engineering experience.  AAS MT, Erie Community College


·         Shubin Ruan, Ph.D, Senior Dynamic & Controls Engineer, will be responsible for orifice design, the testing and performance evaluation of the fluid viscous dampers.  Shubin has

6 years experience in design, testing and evaluation of seismic dampers and semi-active isolation products.  Ph.D. CE, University of Buffalo , MS ME Dalian University, BA ME Jiamusi University .


·         Joseph Schoen, Seismic Project Engineer, will provide testing services and design support to the Seismic team.  Joseph has experience in the prototype and production testing of fluid viscous dampers.  BS Mechanical Engineering, University of Buffalo.


·         Dennis Scully, Director of Operations, will be responsible for all aspects of manufacturing and the QA/QC Program throughout our seismic projects.  Dennis will generate a project based Quality Control Plan.  He has 16 years in construction, engineering, quality and production.  MBA, Duquesne University, BS ME, Gannon University.


·         Dave Smith, Materials and Purchasing Manager, will be responsible for production estimation and materials management and procurement of materials, parts and services.  Dave has 20 + years in material procurement and control.  BS in Management, State University of New York Geneseo, Materials Management Level II, University of Buffalo .





King County Courthouse

Baugh Construction

900 Poplar Place South

Seattle, WA 98144

Contact:                                        Don Kawalchuk  (206-726-3626)

Dates of Project:                         11/02 – 11/03

Contract No:                               

Contract Description;                  (97) 150 Kip x 6” viscous dampers, mounting pins, with spherical bearings



Coronado Bridge Seismic Retrofit

Traylor Pacific

602 Convention Way

San Diego , CA 92101

Contacts:                                      Calvin Casey, Traylor Pacific (619-223-3611)

Dates of Project:                          1/01 – 11/01

Contract No.:                               11-021924

Contract Description:                  (20) 300 Kip x 18” viscous dampers, mounting pins, with spherical bearings


3COM Building

Rudolph and Sletten, Inc.

P.O. Box 4637

Foster City , California 94404

Contacts:                                      Rich Ambidge, Structural Engineer (510-642-3440)

Dates of Project:                         8/25/97 – 2/17/98

Contract Description:                  (63) 200 Kip x 4” viscous dampers, mounting pins, rear tang mounts with spherical bearings


Vancouver Reservoir

Greater Vancouver Regional District

4330 Kingsway, Burnaby BC

Canada V4H 468

Contacts:                                      Tom Nelson, Buyer (604-432-6329)

Dates of Project:                         12/21/97 – 5/1/98

Contract Description: (17) 175 Kip x 8” viscous dampers, mounting pins and brackets.



Santiago Creek Bridge Project

Silverado Constructors / CH2M Hill

2485 Natomas Park Drive

Suite 600

Sacramento , CA 95833-0300

Contact:                                        Hans Standgaard, S.E. (916-920-0300)

Dates of Project:                         10/30/97 – 7/25/98

Contract No:                E94-01

Contract Description: (6) 160 Kip x 18” viscous dampers and mounting pins.


Trump Tower

Canron Construction

P.O. Box 421

Shaw Road , Conklin , New York 13748

Contact:                                        Mike Zilnik (607-723-4862)

Dates of project:                         9/99 – 11/00

Contract Description:                  (16) viscous damping devices for Tuned Mass Damper Project.


Rancho San Justo School Gymnasium

Greg Opinski Construction

145 Riggs Avenue

Merced , CA 95340

Contact:                                        Terry Williams (209-384-2851)

Dates of Project:                         1/99 – 7/99

Contract Description: (10) 24 Kip x 8” viscous dampers


Phalanx Gun System

Naval Inventory Control Point, NAV ICP

5450 Carlisle Pike / P.O. Box 2020

Mechanicsburg , Pa 17055-0788

Contact:                                        Charles Splawn (717-605-4262)

Dates of Project:                         1996-1998

Contract Description: Direct Purchase Phalanx Isolators


Tomahawk Cruise Missile

United Defense LP

4800 East River Road

Minneapolis , Minnesota 55421-1498

Contacts:                                      Tom Danczyk, Engineering Manager (763-572-6581)

Dates of Project:                         1/5/00

Contract Description: (25) DAMSI, Double Acting Mechanical Shock Isolators