Pressure Safety Valve Setting Point

No, unless there is a valid explanation.

yes there is valid explanation .

actual setting point of psv is 6 bar.but pump installed presiding this PSV is giving more discharge pressure of 7.1 bar instead of 5bar . this more raised discharge giving issues poping out PSV below 7.1 . as a remedy, now as per opration request can we change setting point of PSV from 6 to 8 bar?

That is reasonable as far as it goes, but not sufficient. You need also to show that all system components exposed to the increased pressure are capable of handling it.

Only if there is no safety risk due to leakage as in case of steam or chemicals, pressure failure if you are using any pressure vessels in the circuit and these are designed for 8 bar.

All the pipelines and pressure vessels must be tested to at least 12 bar or as per the regulations before making the change.

NO!

What is your psv setting point as per the applicable specification.

That's the specification that would have caused you to purchase the psv in the first place.

Forget the data sheet, for now.

As the above response, no, not without proper justification or authorization.

Absolutely not, agreed. The relief setting is at that limit for a good reason, changing may cause catastrophic failure elsewhere.

No!

And the reason is plentyfold.

You did not mention what the safety valve is for, what system it protects, what working pressure is in the system, what your process requirements are, why you would like to do this and so on.

You seem to fail to understand what a safety valve is for and therefore you should not touch this.

You need to clarify the above points and a lot more to get a clear answer.

So please clarify!

Why would you want to ?

Is the valve releasing?

If so, it is doing it's job.

Sanity is sometimes measured 2 bars at a time........

The safety valve is there to protect something! Rhetorical questions:

• if the setting is 6bar now by design, then why would one want to increase it to 8bar without carrying out a full safety review?
• why is a bunch of anonymous strangers on the internet considered a better source of information than the design documentation and the individuals and firms who designed, installed, commission and maintain it, whatever it is?

http://en.wikipedia.org/wiki/Boiler_explosion

I do no know if you are able to. I have no knowledge of what your capabilities are.

I do have the knowledge to. Also have the knowledge that a pressure setting has a reason. To address this with the manufacture before making any change. To spec out all system devices before even considering it. To address any safety issue that the increase would possibly cause. To question why.

"Can you change the PSV setting from 6 bar to 8 bar?"

Not if the system design safety specifications require the PSV to be set at 6 bar.

I am not sure what the regulations and laws are where you are at but here in the USA performing a PSV pressure setting change such as what you are asking about can and will result in severe civil liability and/or criminal charges depending on the result(s).

Most companies I have worked for require the PSV to be sent out for certified testing and setting as well as detailed documentation for legal liability purposes.

Can we? Most probably can if it is an adjustable PSV.

Should we? That depends on what it is protecting.

Why do you ask?

Is the data sheet you are referring to that for the valve or for the hardware being protected?

Tell us more, with pictures and references preferably, otherwise you will be mercilessly shot down by some of the contributors here.

Ball's in your court Suvarna.....

In addition to a single pressure gauge & safety valve(pressure relief),can't we incorporate a pressure switch set to give an alarm at a set pressure & shut down fuel to burner?.

That's what automated boilers do mate, at least that's what they're supposed to do.

Op didn't say it was a steam PRV, could be compressed air or any other fluid ...we don't know.

Definitely NOT!

1 - There can be explosion depending on equipment you are using, like pressure vessels, and this could be fatal.

2 - Pipeline down the line can leak, causing steam leaks/burns or chemical leaks/burns depending on what the pipeline contains. These could be vary serious/fatal.

3 - There can be technical failures of the equipment even if there may not be serious accident.

You should know why you want to change the setting and how it will benefit/harm the plant and machinery apart from employees working in the area. Such decisions should be taken by competent engineers with adequate knowledge and experience of the system.

If it was selected to lift at 6 barg , than i assume that lift should give the relief capacity- kg/hr.

If we set it 8 barg ( I really don't know what is duty of this safety valve and why it was set to lift at 6barg ) we have to compress the spring further and most likely we may not have the 'lift' to relief the capacity required.

That may well be true as far as the valve itself goes. However, this Mechanical Engineering thread does not reveal the purpose of the valve as far as its Process function might be; at this moment, one doesn't know the temperatures involved and the nature of the fluid being relieved, never mind the quantities and flowrates!

To adopt an almost-blinkered Mechanical Engineering approach to this thread by focussing entirely upon the valve would be at some point in the range from bizarre at one end, through foolhardy and all the way through to criminally negligent at the far end.

Proposal to the original poster: submit the proposed change to a formal HazOp Study group and work from the results of that study.

See also post 1. There are some possible valid reasons and permissible circumstances for making such a change, but the OP seems to have disappeared.

In the lower 48, there are companies that will recalibrate and reset pressure relief valves. And re-certify them. The pricing for the service is not for the faint of heart, because I would guess the insurance and board certification costs need to be covered in the company's pricing structure. Sometimes it is less expensive to purchase a new valve.

In the grand scheme of things, it is best to have a clue before changing the setting of a SAFETY valve.

OP has no such clue.

Or he doesn't know he would get more help by giving us all the clues that he can.

Star Brass in Seattle used to do that, for decent savings over the cost of new valves. I don't know if this service is still active.

If 8 bar is desirable now, Mildred, why was it set to 6 bar originally, and what has changed to provoke an 8 bar setting now, then?