Anti Static PTFE Hoses is an essential requirement in applications where there is the risk of an electrostatic build up on the inside 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 10-7 S/m (Siemens per Meter), such as fuels, solvents, Freon's 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, 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.
If in any doubt, please contact our technical department.
AS grade 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. The carbon is encapsulated by the PTFE and in normal, non abrasive applications will not come loose to contaminate any fluid passing through.
When "AS" (Antistatic) grade hoses is specified, then the hoses supplied will be in accordance with the requirements of BS5958 Part 2, 1991 Clause 19.3, when tested in accordance with EN IS0 8031 Clause 3.1, which requires that the resistance between a plug inserted 25mm into the bore at the end of the hoses assembly, and one of the metallic end fittings should be less than 108ohms.
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.