PURPOSE - GP GRADES

GP is the 'General Purpose' grade, for use in all applications where fluids or gases are being conveyed which do not generate a risk of static charge development (see 'AS').

Design & Approval

GP Grade has a virgin PTFE liner, manufactured from hose grade PTFE which conforms to the requirements of:

FDA 21 CFR 177.1550

Both the PTFE liner tube and the platinum cured silicone rubber cover have been tested and conform to the requirements of USP Class VI both at normal temperatures and at 121°C (250°F).

Pharmaline hose (but not Pharmalex Hose) in sizes 3/4" and above includes a Grade 304 SS wire helically wound in the external convolutions, to reinforce the hose against kinking.

EC - ELECTRICAL CONTINUITY

Electrical continuity requires that the hose assembly supplied is electrically continuous, or conductive, between metal end fittings at each end of the hose. This can apply whether the hose is GP or AS grade.

The requirements for electrical continuity are specified in the German Document BRG132, and the Specification EN ISO 12115, tested to EN ISO 8031 Clause 3.7, which requires that for hose assemblies with a resistance between fittings of ≤10² ohms, a letter 'M' can be applied, or ≤10⁶ ohms, a letter 'Ω' can be applied.

Pharmaline Hose Assemblies are all electrically continuous, and all meet the requirements of both 'M' and 'Ω', but are not stamped unless requested.

Pharmalex Hose Assemblies are not electrically Continuous.

PURPOSE - AS GRADES

AS Grade is an essential requirement in applications where there is the risk of an electrostatic charge build-up on the inside surface of the PTFE tube which may then discharge through the tube wall.

Media passing through which create such a risk are fluids which have a Conductance of less than 10^-8 S/m (Siemens per Metre), or 10⁴ pS/m such as fuels, solvents, freons, some WFI (ultra-pure 'Water for Injection') and non-polar organics which are being transferred at a medium to high flow velocity.

All twin or multi phase media, and any non-mixing media, such as powder in air, or water droplets in steam, in gases or in oil, also colloidal fluids constitute a particular hazard for static charge generation, and always require grade AS.

Design & Approval

AS Grade hose has an anti-static PTFE liner manufactured from FDA approved PTFE, and less than 2.5% of 'high purity' Carbon Black material to FDA requirement 21 CFR 178.3297 and European Commission Directive 2007/19/EC. AS Grade also conforms to the requirements of USP Class VI both at normal temperatures, and at 121°C (250°F).

Specifications

When 'AS' (Antistatic) grade hose is specified, then the hose supplied will be in accordance with the requirements of BS5958 Part 2, 1991 Clause 19.3, when tested in accordance with EN ISO 8031 Clause 3.1, which requires that the resistance between a plug inserted 25mm into the bore at the end of the hose assembly, and one of the metallic end fittings should be less than 10⁸ ohms.

NOTE: When in service, at least one end fitting must be connected to earth, to permit dissipation of the static charge from the end fitting.