Diaphragm replacement needed?

[k374]

My Mares regulator has just been sitting in storage for the past year. I recently took it down to Sport Chalet to have it serviced due to the annual service requirement. Usually the parts are covered but now Sport Chalet tells me that the diaphragm needed to be changed and it was $8 in parts.

Two questions:
Why did the diaphragm required to be changed when I didn't even use the thing since it's last service?

Why isn't this covered by Mares, I thought all parts as part of a regular overhaul are covered. They were the last time around I serviced it.

 

[Fishpie]

Maybe the tech put a hole in it removing it.

 

[Bubbletrubble]

Which diaphragm are you talking about? I suspect that you're referring to the second stage diaphragm.

At least for other reg manufacturers (I'm familiar with Aqualung and Apeks)...
For diaphragm first stages, the diaphragm is usually a part included in the standard overhaul kit.
For second stages, the diaphragm is not a part included in the standard overhaul kit.

For most regs, the material composition of a second stage diaphragm is a thin, rubbery-feeling material (some sort of synthetic polymer). With proper maintenance, it can typically go several years in-between replacement. During a standard overhaul, the reg tech removes and inspects it. If it has no obvious visual defects, then it's replaced and tested functionally. If the old diaphragm passes functional tests, then that should be good enough until the next overhaul.

Did the shop give you the old diaphragm so that you could see the damage to it? I suppose it's possible that it was ripped/torn somewhere. If you've only had the reg for a couple of years, then you might want to look at changing your reg storage conditions. Storing dive gear in the wrong environment (UV, humidity, heat) can cause wearable parts to deteriorate at an accelerated rate.

Or...the reg tech may have inadvertently damaged the part during disassembly (as Fishpie pointed out).

 

[knowone]

The distance cousin of The awap tender of the fleet



See the impressions in the removed diaphragm
and the el cheapo hole saw that materialised into
an awap, even fits the two scrubber cannister caps
and more other things

Mares diaphragm pictured which is smaller than
apeks and not included in any Mares kits I have

Lucky I remembered to remove the drill bit?


Very good.

 

[LeadTurn_SD]

My Mares regulator has just been sitting in storage for the past year. I recently took it down to Sport Chalet to have it serviced due to the annual service requirement. Usually the parts are covered but now Sport Chalet tells me that the diaphragm needed to be changed and it was $8 in parts.

Two questions:
Why did the diaphragm required to be changed when I didn't even use the thing since it's last service?

Why isn't this covered by Mares, I thought all parts as part of a regular overhaul are covered. They were the last time around I serviced it.

The "annual kits" for Mares diaphragm first stage do not contain a diaphragm or HP poppet, since these are not always changed (per the repair manual) at annual service (it is a different topic on whether they should be).

During a full service, the 1st stage diaphragm is removed and inspected, an possibly reused, or replaced .... it is supposed to be blown out with comressed air to prevent possible damage from attempting to pry it out (damage to both the diaphragm AND more critical the 1st stage).

I typically just replace the diaphragm (if I have a spare). Old mechanical "habbits" die hard. I don't service annually, only when "needed"; but when I do go to the trouble of fully tearing down a first stage, I'll typically replace all of the "soft" parts... this is typical "best practice" for servicing many types of mechanical devices.... if performing a service that requires extensive disassembly, go ahead and replace the seals, o-rings, etc.

You'll get a debate on whether the diaphragm should just be replaced whenever it is removed.... it DOES take a "set" from being clamped by the retainer (see knowone's photo). Some brands specify in their repair manual that it is ALWAYS replaced after being clamped once, regardless of how long or short the time was since the last service.

Anyway, not sure what Mares parts replacement policy is... I service my own... but $8 sounds about like marked up "retail" price for a first stage diaphragm... too much for what it is, but not much e can do about that (except make your own, as knowone mentioned!).

Best wishes

 

[knowone]

[video=youtube;CVC2vyVCWJI]http://www.youtube.com/watch?feature=player_detailpage&v=CVC2vyVCWJI[/video]

 

[Greg Barlow]

My Mares regulator has just been sitting in storage for the past year. I recently took it down to Sport Chalet to have it serviced due to the annual service requirement. Usually the parts are covered but now Sport Chalet tells me that the diaphragm needed to be changed and it was $8 in parts.

Two questions:
Why did the diaphragm required to be changed when I didn't even use the thing since it's last service?

Why isn't this covered by Mares, I thought all parts as part of a regular overhaul are covered. They were the last time around I serviced it.

I have been servicing regs for many years, and Mares regs for more than a decade. Mares does not advise that the 1st stage diaphragm be automatically replaced at each service. They do specify that the part be closely inspected for any abnormalities. The impression areas displayed in the above photograph, are not necessarily abnormalities. With that said... I probably have reused at least 80% of the diaphragms I have encountered. In only one case have I found a used diaprhagm to display a leak. My standard procedure is to place a small amount of Christolube on the retaining nut's base, and then torque the nut between 17-20ft lbs.

As LeadTurn indicated, NEVER remove a diaphragm on any reg by using a tool to fit under the edge. To do so will very likely scratch, or gouge, the critical sealing surface. I have seen a large number of regs damaged from this procedure. You should alwasy use a blast of compressed air (50-100psi) through a LP port to dislodge the diaprhragm. It is easier to close off all the open ports with plugs, and then use a soft tip to introduce the air.

When I rebuild vintage regs, I almost always use new diaphragms. vintagedoublehose.com has excellent quality reproductions, which work perfectly on single and double hose regs.

Diaphragms should not be "homemade" without using material that is reinforced with synthetic fibers. Sheet silicone or EPDM does not have the structural rigidity to work properly.

Greg

 

[Capt.Gene]

I never reuse a 1st stage diaphram. They are designed to be crushed into place during the reassembly.
The 2nd time it is installed I feel there is risk it may blow out from under the clamp ring.

 

[halocline]

I never reuse a 1st stage diaphram. They are designed to be crushed into place during the reassembly.
The 2nd time it is installed I feel there is risk it may blow out from under the clamp ring.

I don't often work on diaphragm regs, but I would follow this advice. Once you take it out, there's simply no sense in putting it back in. Same thing for the HP poppet, personally I think Mares is way off on not replacing that.

 

[knowone]

Almost had a heart attack then enlarged the photo and found the synthetic fibres