Engineering Mechanics Corporation of Columbus
Mojave High-Energy Pipe Test Site



Test Site Description
The site is located about 30 miles north of the city of Mojave, California (60 miles east of Bakersfield, California). It is about 3 miles off the closest road, and there is 6 miles of barren land on the other side of the site. Hence, high-energy release test (vessels or full-scale experiments) can be conducted there.

At the site, there is a 1.5-inch diameter pressure line and a 1-inch return line, both having pneumatic remote control valves. The 1-inch line is used as a pressure bleed line, so that if the temperature in the vessel is not sufficient, then nitrogen at a different temperature can be pumped into the vessel. A liquid nitrogen pump truck is used to pump nitrogen at a controlled pressure and temperature down the 1.5-inch line.

Instrumentation in the current Emc2 tests consist of thermocouples, pressure transducers, timing wires, strain gages, and a high-speed digital video.
Specimen Preparation

Specimen fabrication (e.g., welding) can be done at the site or at a local oil-and-gas pipe fabrication shop which is located a short distance away in Bakersfield, Ca.  Emc2 technicians install the timing wires, pressure transducers, thermocouples, and other instrumentation as required.

Instrumentation

Typical instrumentation used is described below.

  • Surface and sheath thermocouples to measure the pipe surface temperature and the gas or liquid temperature in the pipe. These are manually recorded during pressurization and the values at the time just before the initiation of the fracture will be documented. The accuracy of the temperature measurements is better than ±2 C.

  • Pressure is measured from a calibrated dial gage and digital output of a calibrated pressure transducer on the return line. The accuracy of a typical 3,000-psi pressure transducer is ± 0.25% or ± 7.5 psig. The electronic pressure transducer will be calibrated by a traceable dead-weight gage before and after the test.

  • Numerous timing wires will be installed on each vessel. A timing wire circuit box allows for 5 wires per channel and each wire having a unique voltage change. If a shaped charge is used to start the fracture event, one timing wire is put under the shaped charge to document the start of the event. We have developed procedures to protect the timing wires from being damaged by the explosive cutter.

  • An Olympus digital high-speed video camera can be used to document fracture behavior over a one to two square-foot area. This may be useful in some tests, i.e., crack arrestors, documentation of crack-tip-opening angle for ductile crack propagation, fracture behavior as an axial crack approaches a girth weld, etc.

  • For crack initiation tests, a crack-mouth-opening displacement gage (typically an LVDT) and d-c electric potential can be used to document crack initiation and stable ductile crack growth.



Pipe Before Testing

Video Clip of Pipe Test

If you cannot download the correct plugin you can access the video here

Pipe After Testing
Experimental Capabilities       Emc2 Testing Facilities


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