Removing Valves and Installing a Manifold

[Jim Lapenta]

On the bands and manifold the 2mm in diameter is not that much. Height on the other hand can be. If one tank is too short then they won't set right. Whenever we set up doubles we try to match them as closely as possible. Another reason to snug them up laying down flat. Standing up, if the heights are different enough, puts strain on the manifold when you start to tighten them down and tighten the manifold up. The crossbar and valve inlets need to be perfectly straight and line up dead on

 

[Vegan Shark]

How many mm difference is too much for bands? I can't for the life of me find tank bands in Japan. The only one available is from Aqualung, and it's some bizarre harness/band combo, where the tanks touch the diver's back directly, with no backplate or wing attached. So looks like having 7.25" bands shipping from the US is my best bet. 7.25" is 184mm, whereas the tanks I'm looking at are 188mm... is a 4mm difference going to slide?

Also, are manifolds and valves pretty universal? Only manifold for sale is made by Aqualung, but the tanks would be from a different company... worried the neck size/thread count etc. might have variation?

 

[eelnoraa]

... Height on the other hand can be. If one tank is too short then they won't set right. Whenever we set up doubles we try to match them as closely as possible. Another reason to snug them up laying down flat. Standing up, if the heights are different enough, puts strain on the manifold when you start to tighten them down and tighten the manifold up. The crossbar and valve inlets need to be perfectly straight and line up dead on

I agree with Jim here. The high of the tank is probably more important. But it is NOT because different height put strain on the manifold. You should always level the top of the tank so that there is NO strain on manifold. With that, the bottom of the tank may not be even. I have seen a set of double HP100 where the tanks have different height about 1/4". When you hold the tank up, they lean toward one tank. It just doesn't look good.

The height of the crown portion is also important. They should somewhat match as well, so the top band can set at the break of the crown for both tank. A little off is OK, but not too much

 

[Peter69_56]

Check that the manifold you get has threads that match your tanks. I ordered faber tanks and ordered 3/4 NPT manifold. I saw something on here about M25 valves and checked my manifold, guess what, they had sent M25 manifold. Lucky I read the post on scuba board before I assembled them. SO it pays to check. Also you should thread gauge the valves ( and tank neck threads if they are new), never assume everything is within spec. Doing a course I was shown both a new tank and new valve, both outside spec and both failed. Put them together and an accident would happen for sure.

 

[Scubatude]

How many mm difference is too much for bands? I can't for the life of me find tank bands in Japan. The only one available is from Aqualung, and it's some bizarre harness/band combo, where the tanks touch the diver's back directly, with no backplate or wing attached. So looks like having 7.25" bands shipping from the US is my best bet. 7.25" is 184mm, whereas the tanks I'm looking at are 188mm... is a 4mm difference going to slide?

Also, are manifolds and valves pretty universal? Only manifold for sale is made by Aqualung, but the tanks would be from a different company... worried the neck size/thread count etc. might have variation?

Valves are fairly universal assuming thread size is the same, but manifolds are a different story. They need to be appropriate for the band spacing. Usually not a problem, however if you do not have a local supplier, you may be best to get bands and valves/manifold form the same source to ensure they match.

 

[victorzamora]

A big crescent wrench is better. I have over a dozen tanks and use a wrench. A big wrench will give you enough leverage to spin off the valves safely.

Not all valves have a good option for using a big crescent wrench on....unless you mean grasping the body of the valve itself. Also, my whacks are NOT to the knob-side....they're to the stem-side WITH a plug in.

The other thing to mention is that the valves do NOT need to be super tight when you reassemble them. I get mine "snug" and then give it a couple of good jerks to get it HAND tight. I don't use tools and haven't had an issue.

 

[Vegan Shark]

Looks like APEKS here makes bands, so doing everything from the same maker (Aqualung) is possible, albeit overpriced. Cheapest quote I got for tanks, bands, and manifold is $2500 :\ feel like I need to sleep with the tanks at night at that point to make it worthwhile.

...Nevermind, despite tons of emails with Aqualung's rep, and being told it will all work out, when I actually got a shop to try and place the order APEKS says they have no bands in stock, and it will take months to order them.

 

[Jim Lapenta]

2500 is nuts. If you have an apo/FPO order the bands and manifold from the us. Shipping would be around 35 bucks via USPS priority mail and take about ten days. Put together a set of al 80's. I have a used set of bands that will fit those or lp 85's and you can use a dive rite, halcyon, or just about any other manifold. Shipping on the bands would be 15 bucks if you have an apo.

 

[Vegan Shark]

Manifolds have to have a stamp from the KHK (Japan's gas overlords) to get filled here, so US tanks and manifolds are a no go. And unfortunately Aqualung Japan charges $800 for their manifold, because they're greedy/evil like that. I'm already planning on getting AL80s from a Scubaboard member who is a GUE instructor in Japan....but I still want big steel tanks.

 

[Vegan Shark]

My beautiful 14L newborns. Sadly I forgot to take the Aqualung stickers off before putting on the bands....but at least the BPW will cover it up.

Some questions:
(1)I forgot to put flat washers on the back side, as well. How necessary are they really?

(2) Is the crossbar supposed to be loose even at the end? In the instructions they always talk about it 'having play' but I tightened mine, and now it's pretty hard to move...not sure if this is right or not. Will get them filled ASAP to see if there are any leaks.