Phastite push-fit fittings now available in sizes up to 25mm

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Phastite push-fit fittings now available in sizes up to 25mmParker Instrumentation is extending the applications potential of its innovative 'push-fit' fluid connectors for high-pressure industrial applications. Eight new variants enable the 20,000psi (1379bar) rated connectors to be used on larger metric and imperial tubing sizes of 14, 16, 18, 20, 22 and 25mm, as well as 3/4 and 1inch. This extends the cost-savings potential from current small-bore applications into many new areas such as high-pressure hydraulic systems, steam and gas services and supply lines in factories, plants, power stations and ships, and high-performance test equipment.

Assembled by means of a simple push-fit operation, the Phastite connectors provide permanent connections for high-pressure fluid systems. For permanent connections, and these elevated pressures, system builders would typically use either welded or cone-and-thread fittings, which are time-consuming and expensive to install. Compared with these products, Phastite connectors can reduce installation costs by a factor of 90 per cent or more, according to Parker Instrumentation.

Phastite employs a compression assembly principle using a novel form of toothed profile to make the seal. The connectors are supplied as one-piece components. To make a joint, all that is required is to insert the tube, and then push the collar along the connector body until it reaches a dead stop. This operation is performed by a simple hydraulic tool and takes a few seconds. The tool requires no skill to use, and assures users of right-first-time connections.

Quicker and easier

This assembly approach contrasts with the requirement to perform a 360-degree weld around the circumference of a tube, an operation requiring skill, consumables, expensive equipment and up to 10 minutes of time per joint. Alternatively, the coning and threading of a tube end to prepare it for use in a special screw-together fitting - which also requires skill, and time - can take 30 minutes or more. For many applications, the quality of the weld also has to be tested by means of dye penetration or x-ray inspection, thereby adding further significant costs to the jointing process.

Inside the Phastite connector is a sealing system, which is claimed to be unique, and a collar that slides along an angled body; in the process of sliding along the body, a number of circular profiles are compressed into the tubing to form a mechanical joint and a seal. At the end of the short travel is a vertical face that provides confirmation of correct assembly. The multiple profiles mean that less pressure is applied at each sealing point than a traditional fitting. This allows Phastite to be used with thin-walled tubing - which is a further major benefit when compared with cone-and-thread fittings (which require more expensive thicker-wall tubing in order to allow for the threading and coning).

Phastite is much faster to assemble than welded or cone-and-thread fittings, but also simplifies the process, removing a major element of industrial system building cost. The very high degree of control over make-up that the tooling automatically imposes also assures users of right-first-time assembly. This is not the case with welded and cone-and-thread fittings, where many users expect that there will a certain degree of rework. When used to replace a welded fitting, the Phastite connector also eliminates any need for a 'hot work permit', which can be another major equipment building expense.

Application potential

The 20,000psi (1379bar) pressure rating of Phastite fittings opens up an extremely large potential marketplace. Welded and cone-and-thread tube fittings are used in industrial applications where there are pressures above those that can be handled by ferrule types - which is, broadly speaking, above 6000psi (413bar). Applications include high-pressure hydraulics, deepwater oil and gas drilling, ROVs and subsea, laboratory testing, and high-pressure machinery such as waterjet cutters. Welded fittings are additionally used in lower pressure applications if there is a need for a 'fit and forget' permanent connection, or where a leak could have serious consequences. Examples include subsea applications, aerospace, boat building and military equipment, and plants that are remote or unmanned, or have safety implications.

The extended Phastite range now includes straight union, union elbow, 'tee' and union cross connector shapes in imperial and metric sizes from 1/4 to 1inch and 6-25 mm. There is also a range of termination connectors that provide a link between the equipment's fixed, permanent tubing, and any element that needs to be disconnected or maintained.

The assembly tool is an important part of the package, and Parker Instrumentation has developed a compact hydraulic tool for equipment manufacturers. More information is available at

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