Pipe Materials

Material  Names Our Recommendation Fire + Smoke Considerations Mechanical Properties Colour Permeablity  Water Absorption
(comment 1) 		Gas Compability Radiation Hardness Cost Supplier Information
PolyUrEthane PUR okay for non-aggressive gases, better than rilsan for safety burns badly, propagate flame, black smoke much softer than rilsan tubing blue (Angst+Pfister type) 7.01 - 13.88 * 10-10 (air)perhaps high for H2O (comment 2) bad effects with C2H2F4 under radiation, tube becomes brittle and brakes!(comment 4) medium low Angst+Pfister AP 12 0115 0604(comment 7)
Polyamide Rilsan (Nylon) PA11 good chemical resistance, medium for safety burns and drops (only small quantities allowed) rigid; kinks easily if bent transparent milky oxygen 4.0*10-10 water 4'300*10-10 water absorption 1.1%(comment 3) quite good; probably ok even for DME medium low Cern store SCEM 38.40.30.
PolyTetra - FlourEthylene PTFE only small quantities for specific purpose highly toxic and corrosive smoke (to be avoided in large quantities) rigid transparent opaque water absorption < 0.01% CF4 or C2H2F4 may be absorbed and cause slight swelling; possibly bad with DME(comment 5) very poor medium Cern store SCEM 38.86.10
Teflon (PerFluor - EthylenPropylen) FEP only small quantities for specific purpose highly toxic and corrosive smoke (to be avoided in large quantities) very rigid transparent water absorption < 0.01% possibly less absorbent to halogionated gases than PTFE poor, slightly better than PTFE medium Angst+Pfister AP 12 0201 0604
PolyEtherEtherKetone PEEK good very good fire retardents low smoke emitter rigid originally brown water absorption < 0.05% very good; cristalline type is ok for DME, no attack through freons (comment 6) good very high  
Unisil-W Silicon Pressure Tube SI-RU okay for auxiliaries, but can di-polymerize not for chamber gases good reinforced tubing, but fairly flexible transparent opaque ? can be bad good low Angst+Pfister 06.5331.7004-13
Tygon (Grade 3370) SI-RU okay for auxiliaries, but can di-polymerize not for chamber gases good reinforced tubing, but fairly flexible transparent  ? can be bad < 200 kgy ? norton performance plastics


Comments:
  1. At room temp: cm3(stp) cm-2mm-1 s-1(cm hg)-1
  2. From air liquide depends on polymere composition
  3. Oxygen diffusion behaves like a classical leak: doubling the flow results in half the oxygen. Water diffusion is high and largely independent of the gas flow. Possibly saturation due to water desorption from the polaimide material.data from R.C.A. Brown et al. DELPHI 84-8 gas-1
  4. Bad behaviour with RPC gas under radiation tests.
  5. A few gases may give problems with PTFE or Teflon, for instance fluorine, CLF3, F2O,etc.
  6. DME resistance depends on hardening process, some types are good.crystalline:
    • Solid who have regular or symmetric molecuar (cristalline) structure.
    • Amorphous: any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern. (for instance: glass, plastic, gel, etc.)
    • Solids who have unregular (non-aligned) molekular structure
  7. Called flexilon pur.