Asahi Tanks?

[scc135]

I just picked up 2 Asahi HP 100 tanks, and they were manufactured in 7-99 and 6-00. Are these the older types that trim poorly (heavy bottom) or are these of the new type? I did some searching and couldn't tell. Do the new Asahi tanks tanks trim balanced?

 

[Leadking]

If the SP or Exemption number is the same, no change, These tanks were spun, vs the deep draw of Faber, Worthington, and PST's.

 

[scc135]

hrm... ok, thanks.

 

[Leadking]

hrm... ok, thanks.

You seem confused by my answer. If the e or sp number on the tank remains the same it mean the manufacturing process has not changed-they are made the same as in the past. If a different manufacturing process were used, they would need to apply for a new Special Permit and get a new number unless they are a 3AA cylinder.

 

[scc135]

The "hrm" was mostly a disappointed "hrm" because I thought they would have different trim characteristics than the older asahi tanks. I remembered reading a post saying that the older ones were different than the newer ones, but did not see anything about the exception or permit number changing, so was hoping that perhaps the characteristics changed regardless of the permit number. Since you said, no change, I assumed the new more balanced tanks are of a different exception/permit.

 

[oxyhacker]

All the Asahi tanks that Catalina has imported have been made under the same exemption, SP 12079, according to Catalina. So it is unlikely there would be significant changes in their trim characteristics, all being tube-formed tanks, which means they have to have very thick bottoms compared to plate formed/ deep drawn tanks.

 

[airstream]

I had 100's and 120's I really disliked them, they were heavy and your valve options are limited due to the neck / thread size....

 

[quattroluvr]

FWIW, just got new HP Steel Asahi, Sherwood 100's. They are stamped 3442, psi (not older 3500), and came with pro combo DIN/Yoke valves. Mfg date stamp 1-12.

 

[quattroluvr]

... and regards the new HP Steel Asaha/Sherwood tanks. They do indeed come with the standard "3/4" threads that today's popular valves fit. The US quarter fits inside the hole, which the so-called 7/8" 3500 less common thread standard does not.
Asahi made in Japan gives some comfort of mfg quality despite their bargain price.
WRT these 'spun' tanks being heavier than Worthington drawn tanks, Asahi good for drysuit/cold water diving = even less lead to carry.... but if i was warm water diving I'd maybe spend the extra $ for Worthingtons, which are about 2 lbs less negative at 500psi.
Didn't like the China made Harrison brand pro K valves that came with, since I don't trust China mfg, so I'm getting xs brand valves instead for them. They aren't made in China; are made in Taiwan, which is MUCH better. I've done business there a lot and the quality culture is very much better, though it varies. If the USA company is on top of it, Taiwan is fine.