Is 3000 psi an option?

[vaerge]

I'm trying to understand where the 3600 psi pressure for CNG tanks come from.

The testing procedure from the FMVSS even mentions 3000 psi - but I keep hearing elsewhere that it has to be 3600 psi.

So, please, anyone to help me out here?

Thanks!

Edit: It should be "Is 3000 psi an option?" in the thread title, but I can't edit it!

[freedml]

Re: Why 3600 psi? Is 3000 psi an option?

Most commercially available gas fittings and tanks are rated for use at 3000psi working pressure, so I assume that's where the original 3000psi CNG equipment came from, made from existing parts. I don't know why they picked 3600psi for the upgraded pressure. They probably thought it wsa the best compromise between higher pressure to increase range and increased costs to build them.

[vaerge]

Re: Why 3600 psi? Is 3000 psi an option?

Most commercially available gas fittings and tanks are rated for use at 3000psi working pressure, so I assume that's where the original 3000psi CNG equipment came from, made from existing parts. I don't know why they picked 3600psi for the upgraded pressure. They probably thought it wsa the best compromise between higher pressure to increase range and increased costs to build them.

True - that sounds like a good reasoning. However, I still cannot figure out if 3600 psi is an actual requirement, and if so - who says so?

[cnghal]

Re: Why 3600 psi? Is 3600 psi an option?

3600 psi is used only in US as an industry standard or guideline(mo better). 3000psi system parts and tanks are commonly available since most of the world uses 3,000psi. Some countries even use 2,400psi like we used here less than 20 years ago.

[vaerge]

Re: Why 3600 psi? Is 3600 psi an option?

3600 psi is used only in US as an industry standard or guideline(mo better). 3000psi system parts and tanks are commonly available since most of the world uses 3,000psi. Some countries even use 2,400psi like we used here less than 20 years ago.

So if I understand you right, the 3600 psi is an industry standard, and not a legal requirement?

And am I right in assuming that most actually use 3000 psi - also in the US?

[vaerge]

Re: Why 3600 psi? Is 3600 psi an option?

Requirement for what?

Legal requirement for CNG installations.

[AlanTbird]

Re: Why 3600 psi? Is 3600 psi an option?

were I usually fill up there are 3600 pumps and 3000 pumps

I have a sticker that says mine is a 3600 system so I use the 3600 pump.

not sure that helps

[freedml]

Re: Why 3600 psi? Is 3600 psi an option?

It's definitely an industry standard for CNG. Also apparently for pressure washers -- I got a lot of hits for them searching for '3600 psi'.

Everything CNG I've seen has been 3600 psi. The only 3000psi I've seen are older Crown Vics.

[John Mitton]

Re: Is 3000 psi an option?

It should be "Is 3000 psi an option?" in the thread title, but I can't edit it!

Your wish is granted

[vaerge]

Re: Why 3600 psi? Is 3600 psi an option?

were I usually fill up there are 3600 pumps and 3000 pumps

I have a sticker that says mine is a 3600 system so I use the 3600 pump.

not sure that helps

That helps a lot! It means that 3000 psi is not a legal requirement, but really a standard - can be one or the other. Thanks!

[cnghal]

Re: Is 3000 psi an option?

From what I've seen, it seems the OEMs went to 3600psi around MY2000.
Ford E & F series were MY1999 = 3000psi @ MY2000 = 3600psi.

[cngmike]

Re: Is 3000 psi an option?

The big 3 all started at 3000. Chrysler was the first to go to 3600. then GM then Toyota and Honda came out with 3600. Finally Ford went to 3600.

[Devo]

Re: Is 3000 psi an option?

My 2000 Ford Contour is 3000 psi. Since most of the world uses 3000 psi, the parts are cheaper and more widely available (as if you could import them into the US anyway).

(I'm an IT programmer/auditor and mechanic's son and marvel at how we refuse to accept world standards - e.g., the metric system, accounting principles, CNG pressures, etc.)