I have an IWKA UK tank. Many of you will know that UK tanks use a different thread to Australian ones (despite being the same manufacturing standard). Tanks has been regularly tested in Aus with the last test passed only a month ago. I want to replace the valve with a DIN unit.
I am trying to confirm the thread of the tank. Cant find a manufactuting date but I can find tests going back to 4/85, so its at least that old.
Heres the rest of the markings:
IWKA 0-761 EB581
TARE WT 13.14KG WC 10.0L PZ
WP 228 BAR TP 397 BAR
I *think* the valve is 3/4 BSP - but am hoping someone can confirm for sure? Its all in test and good (I've been getting it tested without issues for 20 years) but has a yoke valve and I've moved to DIN. Its a pain using adaptors. Want to buy a DIN valve but need to be sure I am getting the right one. Neck is NOT marked M25 (which I understand it should be if it uses that thread?) and I'm assuming that as a UK tank it would not be 3/4 NSP. (US thread)
Get the valve removed and measuring is the only way to be 100% certain. You'll need to measure the outside diameter of the valve and the thread pitch. Or ask the LDS who last tested it, they would have done the above as part of the test.
I have an IWKA UK tank. Many of you will know that UK tanks use a different thread to Australian ones (despite being the same manufacturing standard). Al
I though it was the other way around down there.
Save yourself the grief and suspicion of "old tank, new valve" syndrome at the fill shop, and forever having to be explaining thread form, pitch and function every time you present it for a fill. And just sell it, scrap it or retire it, it's had a long life Im sure you deserve a new one.
I cant tell (for sure) the thread (no one can) without both a ring and plug gauge on BOTH the old valve and the cylinder neck. Just to be 100% lol
But one thing I can tell you is what the PZ stands for. Peter Zelepukin who was the UK importer of IWKA scuba cylinders back then.
I addition to the gauge check, you will IMHO need a copy of the cylinder drawing. This I may have and will check but its a long time ago. That will confirm the neck thread and form, to the new filler and in addition I would want to see a receipt for the pillar valve showing your purchased a 3/4 BSPP thread.
Besides for Australia I thought you had your own standard for cylinder manufacture but we just shared the same thread
AS2030:1:1999 and before 1997 AS 1777, just checking. Iain Middlebrook
Thanks Ian. Situation is very confusing. If you have a UK tank and have had it for many years and been getting it tested before the regs changed (as evidence by ongoing aus test stamps).....then you can keep on using it. I have got mine tested every year for the last 20 years in aus with its original UK valve - without a burst disk. Never been refused by test station.
Apparently its harder if you have a tank that has NEVER been tested in aus......now you need a valve with a burst disk.
Interestingly you can buy Faber tanks in Aus today from Australian suppliers that are marked BS5045/1/CM/S and have 3/4 NSP thread (ie US thread) for the Australian market.
So no, tank spec does not equate to thread size and yes, although we have AS1777 BS5045 is still ok.....confused.....I am!
In the absence of being definitively told that my IWKA is 3/4 BSP I'll just put up with using the existing yoke valve with a DIN adaptor and keep getting it tested for the next 20 years
That is unless you files can confirm its 3/4 BSP?
I'm happy to see you suffer from the self same idiots in standards as we do, next you will have your dive shops wanting to write the standards.
Still looking for the drawing its in archive just cant remember where I left it as I had the file out last for an old Luxfer drawing I posted for another chap. Just never put the file back I guess.
Although pretty sure its 3/4 BSPP Whitworth form thread, the other hurdle is if it is countersunk of counterbored for the 0-ring, now again the old UK valves can work on either just by using a heaver section 0-ring for the countersunk cylinder version.
If its M25x2 (I doubt it) but another problem is the difference between the UK and the German spec standard for the counterbore.
Hopefully I get to find the drawing tomorrow Iain