Should I buy this HP120 doubles setup?

[jcaplins]

jcaplins, they are a full 2 inches taller than an AL80 which is actually pretty significant, they dive very different on your back. If you looked the link, the manifold is the Sherwood isolation manifold which can't be plugged, have to use different valves.

Alright, you win.

I must have been looking at the wrong line on a spec sheet.

PST hp100 = 23.94"
PST hp 100 = 27.87"
Luxfer 80 = 26.06"
Catalina 80 = 25.1"

Regardless... I prefer a 120; size, weight, volume and buoyancy to an AL80.

 

[tbone1004]

I agree, I greatly prefer them, just wanted to clarify for anyone else reading this thread. The HP100's are generally accepted by more people due to the length, but the E8-119's, 117's, etc give you the HP100 height with the HP120 capacity if you need both.

Those sherwood manifolds are also spectacular, though they do require a bit of knowledge to rebuild them as Loctite is spec'd into their rebuild and they have to be baked in order to get them apart...

 

[stuartv]

jcaplins, they are a full 2 inches taller than an AL80 which is actually pretty significant, they dive very different on your back. If you looked the link, the manifold is the Sherwood isolation manifold which can't be plugged, have to use different valves.

regarding hydro, I wouldn't go to an LDS for the hydro, try to find the hydro shops in your area and take them directly there. I would disassemble them yourself first, bleeding them down pretty slowly to avoid condensation then put the singles valves in yourself with the tanks empty and take them to the hydro shop. Quite a few will actually have a VIP sticker to put on there for an extra $5 since it is federal law that a full visual inspection be performed prior to putting it in the dunk tank for hydro. We get ours for about $20 for hydro and vip, no fill obviously but they sometimes have adapters to put a few pounds in there to keep them sealed.

I believe my LDS does the hydro in-house. It's $35 (for steel), but that includes VIP and an air fill at the end.

And, yes, I may well break them apart and change the valves myself, first. I like knowing how things go together and come apart. When you install the valve, is their a torque spec for that? Maybe it doesn't matter, since the shop will have to R&R them anyway. I don't know that I have the right tool anyway. I have torque wrenches, but I think I would need a socketed crow foot wrench or something like that to go on a torque wrench in order to torque a tank valve correctly. I don't have any of those.

The shop also charges $15 to service a tank valve. Under these circumstances, I was thinking it would be a good idea to have them do that, too, while they have them.

 

[eelnoraa]

HP120 is long. Measurement wise, it maybe 2" or so taller, but it feels very long. For single tank, I don't like it at all. AL80 is the longest tank I feel comfortable with. I will take LP95 or HP130 over HP120. For double, longer tank seems to work well because most people are head heavy.

It also depends on the cost of these HP120. Don't for get to add about $50 per tank for hydro and VIP, maybe another $20 if you have the LDS or hydro place disassemble for you.

 

[stuartv]

Those sherwood manifolds are also spectacular, though they do require a bit of knowledge to rebuild them as Loctite is spec'd into their rebuild and they have to be baked in order to get them apart...

I assume that means that when I disassemble the doubles, I should not follow the reverse of that Dive Rite video. That would have me removing the isolator bar first, then removing the valves from the tanks. From what you posted here, I gather I should leave the whole valve/isolator assembly assembled as is and just unscrew the cylinders from the valves.

 

[tbone1004]

If they do $35/bottle for hydro/vip and fill I'd just do that, easier that way, bit more money but not the end of the world.

wrt disassembly, yes that is correct. Proper disassembly is as follows.

Drain air from the tanks slowly, do this with the isolation manifold fully open and just crack one of the valves, it is rather annoying and depending on how full they are could take a while. If they are full of nitrox, and you have a buddy who dives doubles and the tanks are full full, it would be nice to offer them to him to dive to breathe the nitrox down so it isn't wasted. When they come back, then drain them the rest of the way down to empty.

Once they are empty, open both valves all the way. Loosen the bolts on the bands and try by hand to loosen one of the bottles. They should give, but if they don't, try to quickly jerk them loose with your hands, if they slip, grab a jar opener to get some better grip and use that. Depends on how snug they were put in, but they shouldn't be too bad.

Once the first bottle is loose, spin it all the way out and remove from the bands. Insert the singles valve to cover it and just spin it on hand tight and nudge it snug. If it is the offset Sherwood/Genesis valve I showed you in the PM, just tap the regulator side with the palm of your hand once and that is as snug as it needs to be. The other bottle obviously has the bands and full manifold on it now, so do the same spinning motion to remove the second bottle. Take the valve stems off of the manifold and put them in a plastic baggy and tape to the manifold so you don't lose them. Put in a box somewhere. Repeat valve insertion for the second tank and take them over to the LDS. They'll hydro and vip them. I wouldn't bother with valve service personally, but it's your call. They can't service the manifold since they don't make parts for them anymore, and not sure if the offset Genesis valves still have parts available, but I think they do.

 

[kwinter]

The rebuild is really simple. And baking to break the Loctite seal is suggested but might not be necessary. The correct size drill bit (I think it's 5/16) in the hole and a good wrench can do it.

But the OP is correct about the seats. If the singles valves are Genesis, there is no problem. But if they are Sherwood like the manifold, seats just are not available from any source. You would think that with thousands of those valves still in service, someone would make them and sell them through Trident.


iPhone. iTypo. iApologize.

 

[stuartv]

But the OP is correct about the seats. If the singles valves are Genesis, there is no problem. But if they are Sherwood like the manifold, seats just are not available from any source. You would think that with thousands of those valves still in service, someone would make them and sell them through Trident.


iPhone. iTypo. iApologize.

I am completely ignorant on tank tech. Assume the singles valves are Sherwood. Assume they've been sitting in a box in the seller's garage for a few years.

Am I likely to need new seats?

What is the seat? A piece on the bottom of the valve that contacts the top of the cylinder?

Is there some way I can look at them myself and tell whether they are good, bad, or maybe?

Is it as simple and obvious as I'm thinking it would be (given my ignorance)? Look at the bottom of the singles valve and make sure it looks flat and smooth, with no chips/gouges/dings, so it will mate correctly to the top of the cylinder?

 

[Scared Silly]

I am completely ignorant on tank tech. Assume the singles valves are Sherwood. Assume they've been sitting in a box in the seller's garage for a few years.

Probably a reasonable assumption.

What is the seat? A piece on the bottom of the valve that contacts the top of the cylinder?

The seat is typically a nylon piece that the value stem mates against to form a seal.

Am I likely to need new seats?

Perhaps, if the original valve was not used much it may be fine.

Is there some way I can look at them myself and tell whether they are good, bad, or maybe?

Not unless they are in really bad shape.

Is it as simple and obvious as I'm thinking it would be (given my ignorance)? Look at the bottom of the singles valve and make sure it looks flat and smooth, with no chips/gouges/dings, so it will mate correctly to the top of the cylinder?

That is where there is an o-ring. That is also a seating or mating surface that can sometimes need cleaning up. Typically a new o-ring is all that is needed.

See page 17 of this catalogue: http://www.thermovalves.com/PDF/Thermo Scuba Catalogue_8-1-06.pdf

Once they are empty, ... Loosen the bolts on the bands and try by hand to loosen one of the bottles. They should give, but if they don't, try to quickly jerk them loose with your hands, if they slip, grab a jar opener to get some better grip and use that. Once the first bottle is loose, spin it all the way out and remove from the bands.

A suggestion, once the first cylinder is loosen, do not remove it but instead leave it and loosen the other cylinder. Once both are loose, then remove them. Keeping them together at first gives a bit more mass to work against.

 

[stuartv]

Thanks for all the help, everyone! I got the tanks today. The doubles manifold looks new, and the original singles valves look like they were taken off when they were brand new, put in a ziploc bag, and stored in the box that the doubles manifold came in. I already split them up into singles, put the valves on, and dropped the tanks off for Hydro.

Woohoo!