So you are finally ready to purchase your own regulator (or perhaps just want to know more about that mysterious thing you purchased that seems to breathe so well!).  The regulator is one of the few pieces of gear that will actually improve your diving comfort while at the same time extend your bottom time.  How does the regulator do this?  To answere that question we must first understand the basic components and styles of regulators.  Then we must understand the differences in design techniques.  Ultimately we will spend some time understanding how these design modifications relate to diving on our coast.

THE BASICS OF REGULATORS

Today’s regulators are comprised of two components.  The first component is the first stage of the regulator which is attached to the yolk or DIN valve on your cylinder.  The second portion of your regulator is the second stage which the diver breathes off of.  (NOTE: If you find it difficult remembering exactly which stage is which remember the order in which the air is channeled from the cylinder to the diver.)

THE FIRST STAGE

The first stage of every regulator functions to convert the working pressure of your SCUBA cylinder down to an intermediate pressure which is ultimately reduced downstream by the second stage.  In order to convert the working pressure of the cylinder to something a diver can breathe, manufacturers use one of two methods to detect and adjust the intermediate pressure within the first stage; the piston first stage and the diaphragm first stage. 

Although few people know much about their first stage, the first stage of the regulator is critical to the over all performance of the regulator.  The first stage largely controls how much air may be delivered at any time and the over all work of breathing.  The amount of air that may be delivered to the diver at any given time is measured by the flow rate.  In order to maximize the flow rate to the diver, different manufacturers incorporate different designs in order to minimize the regulators susceptibility to over breathing.  Over breathing occurs when a diver is breathing a volume of air that the first stage can not deliver.  This usually occurs at depth when a divers increased demand for air and the larger amount of volume needed to compensate for the pressures of depth combine to exceed the maximum flow rate of the regulator.  Manufacturers also incorporate different designs in order to ensure a relatively constant effort is needed to get air from the cylinder at any given time.  To achieve this all major scuba manufactuers “balance” their first stages to ensure that no matter the pressure available in the cylinder, the diver will not have to exert an additional amount of energy when a cylinder is running low.  Balanced regulators are the norm today much to the delight of every diver.  Other recent modifications to the first stage include dealing the first stage from contact with water.  While diaphragm first stages are ingerently sealed by their design, recent design concepts have carried over to todays piston first stages as well.  By sealing first stages divers subject their regulators to less wear and tear due to the lack of contact with salt water.  As anyone who lives near the ocean knows, salt in the air alone tends to affect the over all longevity and performance of every component that make up the guts of the first stage.  In the last ten years all of the scuba manufacturers I am aware of have converted their first stages to either balanced diaphragms or balanced pistons.  Balanced first stages are geared so that the diver does not need to increase their breathing effort in order to compensate for lower

The piston first stage

BALANCED First stages

Environmental seals