High pressure fitting
4 Nov 2002
Parker Instrumentation has launched a new tube fitting for liquid and gas instrumentation systems.
The fitting sports a 'rapid assembly' design that will handle pressures up to 15,000 PSI. Based on the familiar, industry-standard compression technique - which allows a fitting to be installed in seconds by simply tightening a nut - the new fittings eliminate the time-consuming 'coning and threading' practices that usually need to be performed in the field when applying traditional high-pressure fittings.
Among the application sectors that can benefit from this innovation are deepwater oil and gas drilling, and industrial laboratories where products are developed and tested under extreme conditions. Instrumentation engineers working in areas such as these can now assemble tubing systems in a fraction of the time previously required.
Dubbed MPI, Parker's new tube fitting range is available in a range of instrumentation sizes to suit tubing with outside diameters from 1/4 to 1 inch, and in a variety of shapes and flow arrangements including straight connections, elbow and tee joints, bulkhead unions, reducers and adapting interfaces.
The fittings may be used on cold-drawn hard (unannealed) 316 stainless steel tubing, or thick-walled (annealed) instrumentation-grade 316 tubing. The fittings also feature nuts coated with molybdenum disulphide, which provides a long-lasting lubricant to help prevent thread galling, and reduces the torque required to create the seal - easing both assembly and the remaking of joints.
MPI's ability to operate at much higher pressures comes from a combination of design factors. New geometries for the ferrules, for example, create a dual mechanical hold onto the tubing wall. And the use of Parker's Suparcase hardening treatment to both of the ferrules provides enhanced ability to bite into tubing. There are also longer tube supporting areas within the fittings to enhance resistance to vibration and line loads.
What's more, Parker has used 'inverted' threads (swapping the sides on which male and female threads are used). This technique allows the pressure-retaining elements of the tube fitting to be made thicker without substantially increasing either the size or weight of the fittings.
As the fittings are based on familiar compression assembly techniques, Parker has designed the component parts in such a way there is no possibility of accidental intermixing with low pressure ferrules for example, or of component interchange with any other fitting (which can be a possibility with products for lower pressure applications).
Furthermore, the maximum working pressures of the parts are printed on the bodies of MPI fittings, along with heat code traceability information.
