How to Test a 2nd Stage SCUBA Regulator

Some divers who upgrade their equipment sell outdated components, such as the regulator's second stage, to other divers. While these items may seem to be good bargains, it pays to closely scrutinize and test all equipment, particularly if it will serve as a lifeline under water--which is certainly the case with a regulator. You can complete visual and simple preliminary tests to determine whether the regulator is in good working order, adjustments are needed by a technician or repair is required. Second-stage regulators can be a good deal if they are compatible with your set-up and are well maintained.

Things You'll Need

• Water
• Bucket
• Scuba tank
• Regulator set-up

Instructions

1. Visually inspect the hoses and second stage of your regulator for cracks, corrosion, discoloration, scuff marks or other damage that may signal a malfunction or attempted repair.

2. Connect your regulator set up to your scuba tank.

3. Place the regulator mouthpiece in your mouth, gently inhale through the mouthpiece and hold the breath. Check whether the suction in the regulator resets after you hold your breath; a watertight regulator will hold a vacuum until you breathe out or remove the mouthpiece from your mouth.

4. Turn the tank valve on to pressurize the regulator.

5. Depress the purge valve on the regulator slightly to check the air-flow rate. After you release the purge valve, listen for any air leaks. If the purge valve needs to be depressed deeply before air flows out, the valve in the regulator may need to be adjusted; leaking air may signal salt buildup or the need for valve adjustment.

6. Fill a bucket two-thirds with water.

7. Immerse the regulator in water and see if any bubbles emerge from the second stage, indicating a leak. Depending on the amount of air bubbles, this can signal a residue or buildup that needs to be soaked and cleaned out, or needed maintenance for O-ring replacement or valve adjustment.

8. Remove the regulator from the water and hold the second stage with the mouthpiece facing up.

9. Slowly immerse the regulator in the water, with the mouthpiece facing up, and determine the depth where it begins to free-flow. If the mouthpiece is submerged before the regulator starts to free-flow, the cracking pressure of the regulator needs to be lowered (service is needed).

Tips & Warnings

• If your regulator passes all normal tests, connect it to a pony bottle and test it out in a pool (as you dive with a full regulator set-up and tank). Progressively test with a pony bottle in the ocean (as a secondary set-up) until you are confident that it is working in a variety of conditions and depths.

• To ensure safety, have your regulator checked by a service technician (at your local dive shop).

• Do not dive with a regulator that is malfunctioning.

• Remember that repairing a regulator yourself without training may void your warranty or may worsen the status for repair.

References

• Regulator Checklist and Inspection

Resources

• Dive Training Magazine: Regulator Basics Part 2-The Second Stage