Scuba Regulators
Purpose
A scuba regulator allows you to breathe underwater while scuba diving. It's important that you are properly trained in scuba diving to ensure your safety.
Features
First Stage
This is the part that fits directly to your tank. Its job is to reduce the pressure from your tank down to an intermediate pressure, about 110 to 140 psi.
- Yoke vs DIN: A DIN regulator screws directly into the tank valve. This style is more popular in Europe and with technical divers. A yoke regulator fits over the top of the tank valve and then is held in place with a tightening screw. This style is more popular in North America and the Caribbean, especially with rental tanks.
- Piston vs Diaphragm: A Piston first stages use a hollow metal piston in combination with a heavy spring to operate the high pressure valve that separates tank pressure from intermediate pressure. Diaphragm first stages use a thick rubber diaphragm with a heavy spring to operate the valve between the two chambers in the first stage.
- Balanced: A Balanced regulator is one in which the pressure on both sides of the valve are equalized, therefore performance is not affected by tank pressure.
- Ports: Most first stages will have 4 low pressure (LP) ports and 1-2 high pressure (HP) ports. The low pressure ports will accommodate your second stage regulators, BCD power inflator hose, and drysuit hose. The high pressure ports will accommodate your gauges and a dive computer transmitter for an air-integrated computer.
- Swivel: If the hoses are allowed to swivel (side to side when attached to the tank) this will allow for easier hose routing and a more comfortable feel in your mouth, less "tugging" feel from the regulator hose. However a swivel is also considered a failure point so may not be desireable for technical diving.
Second Stage
This is the part that you will place in your mouth to breathe. Its job is to reduce the air pressure down to ambient, breathable air pressure. Regulator sets will have a primary second stage and a backup second stage, often referred to as the octo or octopus.
- Balanced: A Balanced regulator is one in which the pressure on both sides of the valve are equalized, therefore performance is not affected by tank pressure.
- Adjustability: Some second stages will have an adjustment knob that allows the diver to adjust the inhalation effort while scuba diving. Also used to prevent free-flowing.
- Dive/Pre-Dive Lever: Used to prevent or reduce free-flowing while at the surface. It is possible to still breathe off the regulator while it is in Pre-Dive, however you will notice it to be a harder breath compared to in Dive mode.
- Upstream vs Downstream Valve: In a downstream valve, the moving part of the valve opens in the same direction as the flow of gas and is kept closed by a spring. If the first stage jams open and the medium pressure system over-pressurizes, the second stage downstream valve opens automatically resulting in a freeflow. In an upstream valve, the moving part works against the pressure and opens in the opposite direction as the flow of gas. If the first stage jams open, the result of over-pressurization may be a blocked valve. This will stop the supply of breathing gas and possibly result in a ruptured hose or the failure of another second stage valve.
Care & Maintenance
Regulators are an expensive investment so you should always take care when storing your regs or traveling with them. Store and carry them in a regulator bag to protect them. After each dive, rinse the regulators well with fresh, clean water. Be sure the rubber dust cover is replaced securely on the first stage prior to rinsing to ensure water does not enter the first stage and potentially damage the regulators or gauges. Prior to using them, inspect the hoses for any cracks or pin holes and check your mouthpiece for any tears or rips. Regulators should be serviced by a professional service technician according to the manufacturer's recommendation (usually about every 1-2 years or 100 dives).