Title: How Much Should You Spend on a Regulator? | Scuba Diving
Headings: How Much Should You Spend on a Regulator?
How Much Should You Spend on a Regulator?
Content: The store should stock at least two major-brand lines of regs and be able to service, on site, what it sells. It should not only offer dealer prep, it should insist upon it. Decide how much you want to spend, and choose something in your price range from that store--even if a marginally "better" reg is available from mail order or from a store you don't like as well. Why? Because your reg will require annual tune-ups to stay in peak condition and to preserve your warranty rights. Plus there's the added bonus that "your" store is more likely to go the extra mile to make sure maintenance gets done right and on time--even when you need an overhaul right before that dream trip to the tropics. How it works: Piston vs. diaphragm first stage
Until regulators incorporate computer chips (which may not be so far off), something inside the first stage has to move back and forth to physically open and close the valve that admits air from the tank. That "something" is a piston sliding in a smooth cylinder or a membrane (like a loose drum head) that flexes back and forth. In both cases, atmospheric pressure and a spring push against one side of the piston or diaphragm to open the valve, and air pressure in an "intermediate chamber" pushes on the other side to close the valve.