Test rigs assembled faster with Phastite connectors

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By using Parker Instrumentation's Phastite push-fit connectors, John Crane has saved considerable time and cost in equipping its new turbomachinery test facility.

Parker Instrumentation's innovative new fluid connector, Phastite, has simplified the construction of a state-of-the-art facility for testing dry gas compressor seals at John Crane's new turbomachinery facility in Slough, UK. The new connector's combination of high-pressure operation and push-fit assembly has enabled the company to make considerable time savings compared with a system built using the conventional options of cone-and-thread or welded tube connections.

John Crane is said to be the world's largest manufacturer of mechanical sealing systems and has invested over £2.4million in its new Gas Seal Test Facility. This included the installation of five new high-pressure test rigs that reproduce a vast range of compressor environments. Upgraded test facilities include the ability to test at higher pressures than was previously possible — up to 800bar (11,603psi). The rigs are also able to test seals with shaft diameters up to 500mm (19.7inches) or at speeds of up to 42,000rpm. Phastite connectors have been used to provide high-pressure connections in two areas: for the permanent flow connections inside each of the five test rigs, and for the permanent flow connections on the large-bore gas service tubes that supply compressed air and helium gases to the test cells.

On previous compressor seal testing equipment, John Crane typically used cone-and-thread style fluid connectors for high-pressure lines, which required substantial time for preparation, and assembly. The recent launch of Parker's Phastite offered a new time- and money-saving option to the equipment builders, allowing these high-pressure connections to be assembled by a push-fit operation taking seconds.

Handheld tool replaces machining operation

The five test rigs simulate the real-world gas pressures that exist inside compressor casings and provide high-accuracy instrumentation to measure any leakage from the seal. Each of the five rigs requires around 20 to 25 permanent high-pressure connections. Compared with implementing these using cone-and-thread connectors, Phastite enabled the equipment builder to eliminate machine-based preparation of the large bore tube ends, and the subsequent thread cutting. Phastite connectors were simply slid onto the tubing ends and assembled in seconds using a hand-held tool.

A spokesman for the equipment builder states: "Phastite gave us a much faster and more efficient assembly process. For high-pressure and high-flow-rate applications, Parker's new fluid connector technology offers a very interesting alternative wherever permanent fluid connections are needed. The connectors are also very attractive for this application because of their intrinsic resistance to vibration."

Phastite connectors are also employed on two large-bore tubing runs that supply compressed air and helium gases to the test rigs. These long pipes carry the gas services around the test bay, above the test equipment. T-shaped Phastite connectors are used to provide junction points for delivering gas into each test cell. In this application, Phastite connectors provided an alternative to welded connections, saving the cost and time of orbital welding. Around 30 joints in total were needed to implement the tubing runs; each of these being assembled in less than two minutes using the handheld tool. The complete installation exercise for the gas services, including cutting and mounting the tube runs, took just one day. The simplicity of this approach allowed John Crane to reduce installation costs to a small fraction of the cost of a welded system.

John Crane's investment sees the company's test bay facilities upgraded to handle twice the previous number of seals being tested, and to allow testing at higher pressures. In addition, the new rigs have a sophisticated data acquisition system that enables customers who are located remotely to monitor testing of their own seals online. This will help to speed delivery, saving time and money for customers who would normally send someone to witness the tests. As John Crane supplies compressor seals worldwide, these savings can be significant.

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