[radioman]

Does a regulator need a pressure release valve?

 

[kevmo911]

Does a regulator need a pressure release valve?

Every regulator I know of, industrial or crap prebuilt, comes with either an integral relief valve or one installed on an outlet port, or both.

The high pressure relief valve will never open up unless it's busted. Generally there isn't an obvious fitting - just some holes. The low pressure relief valve will blow if it's busted, or if there's a leaky diaphragm that allows the low pressure side to increase way too high ...in which case, the low pressure gauge will probably bust as well. And the solenoid will probably blow, and possibly the tubing as well. The needle valve will likely be fine.

 

[jeffkrol]

Every regulator I know of, industrial or crap prebuilt, comes with either an integral relief valve or one installed on an outlet port, or both.

The high pressure relief valve will never open up unless it's busted. Generally there isn't an obvious fitting - just some holes. The low pressure relief valve will blow if it's busted, or if there's a leaky diaphragm that allows the low pressure side to increase way too high ...in which case, the low pressure gauge will probably bust as well. And the solenoid will probably blow, and possibly the tubing as well. The needle valve will likely be fine.

most pressure relief valves (yes on the regulator) don't protect anything on the "outlet" side...Just are meant so as to not blow the regulator to shrapnel..

I've never seen one protecting the outlet..
Personally I add a 60psi relief on the outlet side..
on board is 200psi..

 

[kevmo911]

Maybe we're stumbling over terminology, but when I say "outlet port", I'm referring to the fact that there is usually more than one, and one of those generally comes with an installed relief valve that's set somewhere around double the max outlet pressure plugged into it. Here's a data sheet for a single stage Victor SR-250, which comes stock with one of two types of relief valves. I have a VTS-250 sitting on my desk here, and it's got two outlet ports, and one of them has a stock 300 psi relief valve. I've got a Concoa with the same type of thing, in about the same place (5 o'clock-ish). And I agree they're designed to protect the regulator, not anything connected to it.

Without taking it apart to confirm, I suspect that you could switch the positions of the relief valve and post body with no issues.

It talks about the relief valve in the "Assembly" section.
http://victortechnologies.com/IM_Uploads/doclib_8028_DocLib_2304_56-0607 SR 250 Series Regulator.pdf

 

[jeffkrol]

somewhat semantics.. first a "what if" case..
what if.. both of the stages fails "open" in a 2 stage. At best the pressure will relieve at 200psi.. sending 200psi downstream to an atomizer,reactor ect..

so nothing downstream of the regulator is "protected".. only the regulator is protected from blowing apart.. your downsteam lines/bubble counters ect.. not so much..

NOW this is very unlikely..

As a practical matter:
my Victor lost the seat in the hp diaphragm.. but I could "charge" the regulator w/ the tank valve. 200psi would blow but re-seat below 200psi (after shutting th tank valve off) allowing the primary to maintain a charge and 2)the secondary send 35psi downstream.. Ran this way till I replaced the regulator..The large Victors contain a lot of gas and I prefer to dribble CO2..
Basically I had a 1 stage regulator..
Point was I didn't blow the second stage.. Theoretically if that went the 60psi relief would keep the system from destroying itself...and the hiss would alert me.

I actually find it interesting that most DON'T put a downstream one in.. Maybe I'm just more paranoid..............

EVERY regulator I ever saw has this disclaimer (not that I've seen EVERY regulator and there could be some BUT the marketing blurb better state "protects downstream stuff":

External self reseating relief valve not designed to protect downstream apparatus (No relief valve is needed on SR 260 and SR 261 series regulators)

http://store.cyberweld.com/visr250sere.html

So you were correct but I thought a bit of clarity was necessary...(re-read it and believe I was thinking about the above when I did the first time)

Like this.. there is only 1 pressure relief valve 9 oclock .. and set at like 200-300psi..:

 

[kevmo911]

I don't disagree with anything you just wrote. Though I will point out that the pic is of a VTS (or SR?) -450, not a -250

 

[jeffkrol]

Vts250 only has one relief valve too...4:00

http://www.barrreport.com/forum/bar...les/8483-fs-2-victor-vts250-series-regulators
concoa:
http://www.concoa.com/docs/catalogs... Catalog/400 Series/ADC3010 AE 402 Series.pdf

**Standard assembly does not
include relief valve

When outlet pressure can go to 500psi..

5: 0-500 PSIG
(0-34 BAR)**

4025XXXX

 

[kevmo911]

I feel like you're trying to pick fights, and I'm willing to concede to whatever you're trying to say, as I don't believe it's substantively different from what I said. And yes, the relief valve might be closer to 4 than 5.

 

[jeffkrol]

Not at all. Just stating the limits of the regulator's protection. No more, no less. Your statements were confusing to me actually.

... comes with either an integral relief valve or one installed on an outlet port, or both.

thought that was open to misinterpretation...
I wanted to make sure that people understood the protection was not meant for the "outlet" but more for the internal strain on ONLY the regulator..

sorry, sometimes things come out more confrontational than meant to be..

Secondly it opened up a port to wonder why nobody else addresses what I think is a "possible" issue.. protecting your "stuff" downstream..