Each individually calibrated Cortest Proof Ring is accompanied by a conversion chart that can accurately determine specimen load. Provides sustained specimen load under a stress state of uniaxial tension. Ring deflection is measured by 8-9" micrometers, with the supplied dial indicator providing a check. The entire method is in accordance with NACE Test Standard TM-01-77, and provides data required for NACE Material Standard MR-01-75.

 To accurately meet your needs, the Cortest Proof Rings are fabricated from precision-machined alloy steel and are available in four load ranges up to 250,000 psi, (based on 0.252" diameter specimens). Tension on the Proof Ring is quickly and easily adjusted using a standard wrench on the tension-adjusting screw and lock nut. A thrust bearing distributes the load and prevents seizure.

To provide the most accurate test results, specimen grips on the Cortest Proof Rings are of stainless steel to be fully resistant to the test environment. The standard environment chamber itself is carefully machined from clear, durable acrylic to permit instant visual observation of the specimen at all times. Pyrex glass vessels are also available as standard equipment. The environmental test chamber is secured by o-ring seals that fully prevent any leakage.

As a facet of Cortest's Total Systems Approach to corrosion and electrochemical testing, Proof Rings also have quick, changeover accessories to effectively meet your needs. The accessories include a high temperature package enabling testing at temperatures up to 100°C; a fracture mechanics package with LVDT mount to provide crack growth and load relaxation data on precracked specimens; and automatic control panels with elapsed time indicators, metering and control valves for individually operating from 1 to 24 Cortest Proof Rings under a single fume hood.

Currently the Cortest Proof Ring is being used extensively in petroleum exploration, production, and research. Proof Rings are also widely accepted in the welding, marine, and food processing industries for obtaining data on the effects of a variety of acetic and caustic environments. Because only the highest quality materials are used throughout, the durable Cortest Proof Ring can be used repeatedly and almost indefinitely under normal conditions.

Proof Rings

* Based on a 0.252" diameter specimen.

When selecting stress range it is advisable to use the range most clearly matching the maximum stress level expected, thereby maintaining optimum accuracy.

Cortest, Inc. has a staff of qualified specialists to assist you in every phase of corrosion testing, materials selection, failure analysis, data analysis, and technical consulting. The Cortest Total Systems Approach integrates Cortest's state-of-the-art equipment, with highly trained professionals to meet all of your corrosion and electrochemical testing needs. Cortest representatives worldwide provide prompt service and a comprehensive program to aid in implementing the system.

Pyrex Containment Vessel
An impact-resistant Pyrex containment vessel is now available as a replacement for the standard acrylic vessel used in the Cortest Proof Ring. These vessels may also be used in Cortest Constant Extension Rate and Corrosion Fatigue Load Frames.

Design specialists at Cortest developed the containment vessel to fully comply with revised NACE Test Standard TM-01-77. Because the one-piece Pyrex containment vessel is inert and will not discolor or contaminate test environments through the absorption of H₂S or the release of plasticisers, your test results will remain consistent throughout the life of the vessel.

Of course, all fittings are compatible with those of the standard vessel, and correct orientation of specimens is assured by accurate axial alignment of the sealed openings. The specimen seals, featuring Teflon© seats and Viton© o-rings, are designed such that the impact of specimen failure is absorbed by the Proof Ring or load frame and not by the vessel. This design effectively prevents vessel cracking during normal use.

Optionally available are ports and fittings to accommodate saturated Calomel reference electrodes and counter electrodes for electrochemical measurements and control during testing.

High Temperature Vessel
The Cortest High Temperature Vessel replaces the standard Cortest Proof Ring Environment Containment Vessel for testing at temperatures above ambient. Specimens may be tested at temperatures up to boiling, and changeover from one vessel to another takes less than five minutes.

For safety and convenience, the Model 12.6 Temperature Control includes a fuse, on-off toggle switch, and a pilot light. It may also be used with Cortest TemPressure Vessels.

Elapsed Time Monitors and Controls Panels (Model 52000)
The Cortest Elapsed Time Monitors and Control Panels permit the independent regulation of up to 6 Cortest Proof Rings. Now, a single technician can simultaneously conduct multiple tests on one, several, or an entire battery of Proof Rings. When used with several Proof Rings, the Elapsed Time Monitors and Control Panels permit generation of a complete stress vs. time-to-failure curve on a single bench-top installation.

Standard Elapsed Time Monitors and Control Panels are available for single, four and six Cortest Proof Ring installations. Customized monitors and panels may also be made available for servicing up to twenty-four Cortest Proof Rings.

Cortest Elapsed Time Monitors provide an easy-to-read digital display of test duration for each Proof Ring in the system. A pilot light for each channel indicates which Proof Rings are actively conducting a test. Upon specimen failure, the display for that individual Proof Ring automatically stops and the pilot light turns off to signal test termination. A pushbutton quickly and easily resets individual timers.

Each channel of the timer panel is independently switched and fused, so that the power can be turned off at any single Proof Ring without any effect on the others. An overload on any one channel will not shut down the whole system.

Cortest Control Panels provide accurate, safe flow of two gases (typically nitrogen and hydrogen sulfide) for each Cortest Proof Ring in the test battery.

A three-way valve for each channel is used to select between nitrogen (for a purge), off, and hydrogen sulfide. The flow rate to each Proof Ring in the system is easily controlled by means of a separate metering valve on the control panel.

Many safety precautions have been taken in the design and manufacture of the Cortest Elapsed Time Monitors and Control Panels to protect against the potential hazards inherent in handling high voltage electricity and high concentrations of H₂S. Voltage, for example, is transformed from 110V at the control panel plug to 6V at the Proof Ring microswitch. This minimizes the hazard of electrical shock and sparking under a fume hood.

All valves in the control panels are manufactured from 316 stainless steel. Other components are made of nylon, and are resistant to H₂S gas. A master switch and fuse protects the entire system.

Cortest Elapsed Time Monitors and Control Panels can be connected and made operational in minutes. Standard Control Panels plug-in to any 110V, 60Hz outlet, with 50Hz, 220 or 240V systems available if specified. Once installed, they are maintenance-free, and capable of conducting many tests simultaneously, safely and accurately, under the part-time supervision of a single technician.