Join DiveBuddy.com

Meet new scuba divers, maintain a virtual dive log, participate in our forum, share underwater photos, research dive sites and more. Members login here.

#6242
300 bar din valve thread repair
ScubaCrab - 10/03/2013 5:27 PM
Category: Equipment
Replies: 16

I have a 300 bar din valve with a small ding outside edge. Simple fix with the right tools! Being a common problem with as many valves out there you would think any shop that services equipment would be able to repair. No luck with dive shop’s being able to fix or direct you where to get it fixed or I have a 300 bar din valve with a small ding outside edge. Simple fix with the right tools! Being a common problem with as many valves out there you would think any shop that services equipment would be able to repair. No luck with dive shop’s being able to fixed or direct you where to get it fixed or tools.
So in scouring the internet, scuba forums and measuring with tread gauge and caliper’s I determined dit to be a British standard. BSP parallel thread allso known as Whitworth threads as well 55 degree pitch threads (unlike US 60 degree threads) 5/8"x 14 threads per inch. Din ISO 228 (Din 259) BSPP British Standard Pipe Parallel) nominal diameter G 5/8", major diameter mm 22.91, minor diameter nut mm 21.13, tapping drilsize mm 21.00, TPI 14, pitch 1.814.
Tried to find a tap to chase the thead’s to repair. With all my search’s finding supplier’s in Europe or Australia with exspensive shiping. With all the scuba valve’s used in the US I thought it would easier! Anyone know a source? It allso seem’s like someone would make a special tapered plug or bolt as a tool to straiten any out of roundess to original specs.
Anyone have affodable suggestion’s? Hate to relace a good valve!
#6242
Subscribed
ScubaCrab - 10/03/2013 5:49 PM
For aprox $100.00 I could buy another valve. Or if I hade the tool’s I would have the assurance another valve could be fixed If there was another minor incident sometime!
#5643
tshark - 10/03/2013 5:52 PM
I think it would be cheaper & easier to replace it Im sorry thats not what you want to hear Save the old one for parts Good Luck
#6242
Subscribed
ScubaCrab - 10/03/2013 6:11 PM
I agree for most people I would advise them to replace as for it would be cheaper and most are not skilled enough to do it right! But for me it is an easy fix as for I have worked in a machine shop and repaired thing’s all my life. Also have a lathe but it does not do metric thread’s. A tap is an easy cheap fix if found in the US at a fair price.
#5471
Subscribed
DiveBuddyChgo - 10/04/2013 4:17 AM
Din valve cost $60-$70. Its also illegal to rethread the valve. If its on an alum. tank make sure the neck of the tank isn’t cracked before you spend $ on a new valve. Putting yourself up for an expensive lawsuit if your rethreaded valve fails. Its good insurance to replace.
#6242
Subscribed
ScubaCrab - 10/04/2013 4:39 AM
I measured the minor damage an it is only 10 thousanth’s of an inch! Do you have proof that it is illegal to rethread or this just the fear and hearsay of some in our world of lawsuit’s and liability? This is manifold valve for double’s 300 din which is more expensive!
#6242
Subscribed
ScubaCrab - 10/04/2013 4:58 AM
I am very carefull of liability and safety issue’s from frivilous lawsuit’s and would not jepordise safety or the chance of a lawsuit! My Dad practiced law for 50 year’s and have seen many time’s unfounded lawsuit’s. The minor damage is only an area no bigger than your finger nail 10 thousanths smaller than machine spec’s brass is very soft and not large enough to compromise structural integrity. Still more tread’s and metal than a 200 bar valve which is more common.
#7355
Subscribed
UWnewbee - 10/04/2013 5:44 PM
if this ding is on the very outer edge the crucial point would be the starting of both threads,, but if its that minute as you say you could try a variable speed dremel tool with a fine grit small flat disk on a low speed, 1st plug the rest of the fitting with a rag, burnish off the ding carefully not cutting into the other threads and not taking too much stock off or you can alter the mating of both threads resulting in a cross thread. pull rag out an use tank pressure to blow clean,, you dont have to be in 50 years of law but atleast 25 years of being a machinist can help lol,, good luck
#6242
Subscribed
ScubaCrab - 10/04/2013 8:31 PM
Found the right taps at LPR Toolmakers in Australia https://lprtoolmakers.auctivacommerce.com bsp Parallel taps 5/8-14 TPI inc Starter & Plug and a BSP die Nut 5/8-14 TPI Parallel type. Now I can fix it right any time there is a problem!
#6242
Subscribed
ScubaCrab - 10/05/2013 4:26 AM
I agree that make’s good common sense. It would be interesting and infomitive to know the source and exact wording. All though law’s and regulations do not always make common sense! We could also argue the intent and or interpretation of said law or regulation that we have not seen yet.
Because of acceptable variances some thread’s are better or closer to optimum tolerance. I can scwew my regs and fittings into the valve but at the dive shop it is too tight to attatch there pressure gauge. Making it very easy for someone else unintentionally cross threading a good but not perfect thread. Brand new valves pass acceptable specifications but could be better!
#7355
Subscribed
UWnewbee - 10/05/2013 5:16 AM
the laws are with the dot, stating that any removal of stock could weaken the valve thus the tank would be condemned, But any repairs modifications can be only done by manufacturer. im sure if you sent a tank back to luxfer and after the shipping costs and the repair cost, which theyd more than likely change the valve, more than likely cheaper an easier of you or the dive shop replacing the valve
#6242
Subscribed
ScubaCrab - 10/05/2013 6:41 AM
Ok let’s get more factual here. DOT regulate’s allot of thing’s. Can someone come up with a link with the exact wording.
The valve is separate from the tank any problem with a valve does not condem a tank. Repair’s and or modification’s can only be done by the manufacturers has to be untrue because dive shop’s rebuild valve’s all the time. Witch would be a repair. Tank’s on the other hand if they have unacceptable cracks, pits fail hydro or do not meet any of Dot minimum standard’s it is to be condemned. I am unsure what the manufacturer does. But shippers do not allow tank’s shipped without removal of the valve. Also the valve and the tank are two different manufacturers.
#7355
Subscribed
UWnewbee - 10/05/2013 4:28 PM
due to the gov shut down the site isnt running at 100% but heres a starting point you can look at, good luck in your quest as the dot is broken up into many different areas, truthfully i really dont care about law, theres many we break on our own we dont even know about,, such as, throw that scuba tank in your trunk, wrong! by dot law it should be in the upright position and secured tighly, do we do that? nope. i dont.. ra walker, theres so many rules that get bent, earlier you said straighting is good, but removal of stock, is this refacing tool you say which is not on the psi site anymore, does it shave/cut into the seat? which would be against your earlier posting,,, enjoy your reading material,,, http://phmsa.dot.gov/hazmat/regs/sp-a/approvals/cylinders
#6242
Subscribed
ScubaCrab - 10/15/2013 6:02 AM
Recieved taps and die’s yesterday. Wow quicker than most local dive shop’s! Perfect fit valve’s are better than many new valve thread’s cannot even tell there was ever a problem!
#7355
Subscribed
UWnewbee - 10/26/2013 1:04 AM
Glad all turned out good in the end