Regulator Testing Equipment

[buddhasummer]

It's funny the tools we think we need. Up until recently I've always used an inline adjuster to set lever but it's an Apeks tool with only slotted end. I rebuilt some recently purchased HOGs last weekend and of course couldn't use the adjuster so did it the "long" way. I actually found it easier to make small finer adjustments using a hex key and because the hose only needs to be finger tight connecting and disconnecting was very easy. Whole process maybe 5 mins. I've always use a mag gauge too, think I'm going to try the sink method. I'm relatively new to the self servicing game so it's interesting to read what the more experienced folk do and what you can make do with. Cheers.

 

[WhiteSands]

Place the second stage into water with the mouthpiece facing up with no water in it. SLOWLY lower it until the reg just starts to open, then measure the distance from the water line to the face of the reg, that is the cracking pressure in "inches of water column" (or mm of water if metric). I would subtract about 1/4 inch from that number to get a closer aproximation since there is some space between face of the reg and the diaphragm which is where the measurement is actually supposed to be taken from. If the mouthpiece gets close to filling (or does) then the cracking pressure is too high, at least for a primary, octos will be a some deeper depending on tech preference and design. Reg specs differ but somewhere around 1 to 1.5 in is normal. If the reg has a venturi lever,set it to "-" or min. It will not affect the measurement but it will help prevent a freeflow and a face full of water. If the reg has a cracking pressure adjustment, it needs to be set to minimum or just tighter than a slight free flow. This a a good go/no go test that can be done anywhere in just a few seconds since it can be done to any reg in any water.

Thanks Herman for the detailed instructions.

Just to confirm, both the lever and adjustment knob should be set to their minimum settings, i.e. the setting which makes the 2nd stage hardest (i.e. requires greatest effort) to breathe from, is that correct?

 

[buddhasummer]

Thanks Herman for the detailed instructions.

Just to confirm, both the lever and adjustment knob should be set to their minimum settings, i.e. the setting which makes the 2nd stage hardest (i.e. requires greatest effort) to breathe from, is that correct?

Not quite, easiest effort, turn adjuster all the way out i.e CCW.

 

[herman]

Easiest, not hardest as long as the reg does not have a slight freeflow when you do, at least for the cracking pressure adjustment (knob). Most manuals call for the minimum cracking pressure adjustment to be set such that the reg does not freeflow at all when at minimum. I usually set mine so there is the slightest amount of FF with it all the way out, again a personal preference and not how I would set up a reg if I were doing it for paying customers.

The venturi lever adjustment will make no difference in the cracking pressure of the stage but it will effect how the venturi performs after flow as been started. How much venturi action you get is a totally different test and its more of a personal choice than anything, some like the feeling of having the reg force feed them slightly (large venturi) and others don't. The biggest reason not to set the venturi lever to +/Max is to prevent the large freeflows it will cause.....and the the resulting face full of water.

 

[WhiteSands]

You guys are awesome! Thanks!

 

[herman]

If reg service really interest you or you are just a info geek (I am) then consider copies of "Regulator Savvy" and "Maintainance and Repair of Scuba Regulators". The info in those 2 books will answer all of your questions. I reread my copies every few years and still pick up a thing or 2, money well spent for anyone interested in the inner workings of regs wheather to learn DIY or just to know when a tech is BSing you.

 

[scorman]

Herman,
Finally got around to building the manometer ..getting ready for trip to Coz next week.

Again it's a big help if you have some way of measuring the cracking pressure of your reg, build a manometer if for no other reason than to help you recognize what a good cracking pressure "feels" like. With some practice you can get a fair guess of how the reg is set up.

Cost was zero ...scrap wood, two screws to make into a stand, two feet of vinyl tubing, kid's left over plastic ruler, one drop veggie dye, 5" piece of inner tube, coax clips to both hold the ruler in place and allow 1/4" tubing "loop" to slide up and down to zero at the 3inch mark.
Used a piece of bike inner tube , folded back on itself to slip on second stage and old mouthpiece. punched a hole in the rubber to insert the 1/4" tube.
Worked like a charm with adjustment of only 1/8 turn to set to proper draw. Only need to measure on one side of rule and then double number ie 3/4" reading is 1.5" water pressure head for cracking.

Thanks once again to all on this thread who contributed.
Stew Corman