How to Set Up Double Scuba Tanks

Setting up dual tanks for a dive is not difficult. Though most recreational divers will utilize a single tank for the duration of their diving lives, dual tanks are a necessary component for technical nitrox and trimix dives. With just a few basic hand tools and materials, double tanks can be set up and ready in a short amount of time.

Things You'll Need

  • Lube
  • Tape measure
  • 6-inch adjustable wrench
  • 1/2-inch open faced wrench
  • 5-inch threaded bolt, 2
  • Washers, 4
  • Locking washers, 2
  • 1/2-inch nuts, 2
  • 1/2-inch nylon lock-nuts, 2
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Instructions

    • 1

      Place the two tanks side by side on a table. Remove the valves from the tanks. Loosen the valves by hand and turn to the left.

    • 2

      Grab the manifold and unscrew the two outer valves from the central isolator valve. Screw these two outer valves into the two tanks, keeping them straight to avoid cross threading. Tighten as much as possible by hand.

    • 3

      Lube all exposed o-rings on the isolator valve. Use an appropriate lube such as Christo-Lube, if running high levels of oxygen.

    • 4

      Orient the tanks on the table so the open ends of the valves are facing each other and parallel to the table top. Find the two nuts on either side of the isolator valve. Orient the isolator valve so the nut with the groove going around it is on the right side, the diver's right side.

    • 5

      Screw the isolator valve into each end of the tank valves. Do this correctly and the tanks will slowly draw towards each other while the isolator valve threads in on both ends. Do not completely tighten the valve.

    • 6

      Pull the tanks so the ends hang off the edge of the table. Install the first tank band by sliding it on from the bottom. Slide the tank band up until it is just below where the curve of the upper tank begins.

    • 7

      Slide the second tank band onto the tanks a few inches up from the bottom. Place the edge of a tape measure at the center of the hole of the top band. Slide the bottom tank band up so the center of the hole is exactly 11 inches from the top hole.

    • 8

      Screw a half-inch nylon lock-nut onto one side of a five-inch threaded bolt. Use a six-inch adjustable wrench and screw the lock-nut on until there is 1/8-inch of threaded rod showing above the lock-nut. Ensure proper grip by screwing a wing-nut onto the opposite end of the threaded bolt. Screw a nut onto the same end of the bolt so the bottom of the wing-nut lies flat on top of the nut. Tighten by hand. Grab this end while using the adjustable wrench to tighten the lock-nut in position.

    • 9

      Remove the nut and wing-nut. Slip a washer onto the bolt and slide it down to the lock-nut. Place the open end of the bolt through the bottom hole of a tank band and then through the top hole. Slide a washer on the open end of the bolt. Slide a locking washer on top of the regular washer. Screw on a nut by hand to secure the band in position. Repeat these steps for the other band.

    • 10

      Measure a second time to ensure there are 11 inches between the bolts on each band. Tighten the nuts using a half-inch open-faced wrench. Check to ensure that the isolator valve isn't binding while tightening the nuts.

    • 11

      Use the adjustable wrench to tighten the locking nuts on the isolator valve.