A 3 inch  ID high pressure hose can be used as an electrolyzer
enclosure that can be sealed at each end with hockey pucks.

To make it follow the directions below:

  1. A 5/8th inch hole is drilled at least 1 inch from each end through
      both sides of the hose.

  2. A hockey puck is inserted in each end with a little Dow
      Corning #4 compound for sealing. Make sure it is
      inserted beyond the 5/8th hole.

  3. A 5/8th inch bolt is inserted through each hole
 
  4. Secure the bolts with nuts and washers.

  5. Secure the hockey pucks with stainless steel hose clamps.

  6. Before closing the second end go to step 7.

  7. Drill a 5/8th hole in one side some where along the length
      of the High Pressure hose and insert a valve stem in it.

  8. Test for leakage at up to 60 PSI.

  9. As you increase the pressure you will hear a pop as each
      hockey puck shifts until it rests against its respective bolt.

10. This can be easily taken apart by just letting the pressure
      off and then removing the bolts and forcing out the pucks
      by applying a little air pressure after the hose clamps have
      been loosened.