Previous in Forum: Help! Paidar Chair Pump   Next in Forum: HDPE Covered Lagoons for Biogas Capturing
Close
Close
Close
28 comments
Active Contributor

Join Date: Nov 2009
Location: IVRCL,India
Posts: 12

Pressure Safety Valve Setting Point

04/28/2014 7:06 PM

Can we change psv setting point from 6 bar to 8 bar ? our psv setting point as per data sheet is 6 bar . Pls clarify anybody , advanced thanks ,

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 791
#1

Re: Pressure safety valve

04/28/2014 7:12 PM

No, unless there is a valid explanation.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Active Contributor

Join Date: Nov 2009
Location: IVRCL,India
Posts: 12
#26
In reply to #1

Re: Pressure safety valve

06/15/2014 4:06 AM

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?

Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 791
#27
In reply to #26

Re: Pressure safety valve

06/15/2014 11:04 AM

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.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply Score 1 for Good Answer
Power-User

Join Date: Sep 2007
Location: I am located in Mumbai,India.
Posts: 126
Good Answers: 2
#28
In reply to #26

Re: Pressure safety valve

06/15/2014 11:08 PM

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.

__________________
Rajesh
Register to Reply Score 1 for Good Answer
Guru

Join Date: Oct 2008
Posts: 42369
Good Answers: 1683
#2

Re: Pressure safety valve

04/28/2014 7:23 PM

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.

Register to Reply
Guru
Canada - Member - New Member

Join Date: Jul 2013
Location: Canada but south of 49
Posts: 895
Good Answers: 20
#17
In reply to #2

Re: Pressure safety valve

04/30/2014 8:16 AM

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

__________________
Never stop learning
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15449
Good Answers: 954
#3

Re: Pressure safety valve

04/28/2014 7:25 PM

I have no idea what this safety valve is connected to. I do know that safety systems should not be touched by anyone that does not know what they are doing. You asked us for advice on a safety system. By definition, you do not know what you are doing. Do not work on this safety system.

CR4 ADMIN: Modified Post

Abuse/Attack: A portion of this post was deleted because it was an attack on another user. Please review the CR4 Site FAQ and the CR4 Rules of Conduct.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Off Topic (Score 5)
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15449
Good Answers: 954
#6
In reply to #3

Re: Pressure safety valve

04/28/2014 10:17 PM

I was just trying to help them achieve their obvious goal without putting others at risk.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Off Topic (Score 5)
Guru

Join Date: Oct 2008
Posts: 42369
Good Answers: 1683
#7
In reply to #6

Re: Pressure safety valve

04/28/2014 10:22 PM

Quit cher whining and go sit on the naughty set until we tell you to come out.........

Register to Reply Off Topic (Score 5)
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4424
Good Answers: 108
#8
In reply to #6

Re: Pressure safety valve

04/29/2014 1:17 AM

I like your post better the way it is now!

__________________
Common Sense Dictates
Register to Reply Off Topic (Score 5)
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4424
Good Answers: 108
#4

Re: Pressure Safety Valve Setting Point

04/28/2014 9:29 PM

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!

__________________
Common Sense Dictates
Register to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1587
Good Answers: 125
#5

Re: Pressure Safety Valve Setting Point

04/28/2014 9:41 PM

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........

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 31525
Good Answers: 833
#9

Re: Pressure Safety Valve Setting Point

04/29/2014 7:31 AM

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

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#10

Re: Pressure Safety Valve Setting Point

04/29/2014 7:40 AM

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.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Guru

Join Date: Nov 2007
Location: Eastern Arizona mountains on Route 666 about a mile from God's country
Posts: 1676
Good Answers: 122
#11

Re: Pressure Safety Valve Setting Point

04/29/2014 10:26 PM

"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.

__________________
They said; "Brain size?" I heard; "Train size?" so I said: "I'll take a small one, thank you."
Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#12

Re: Pressure Safety Valve Setting Point

04/29/2014 10:32 PM

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.....

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Guru

Join Date: Jun 2010
Location: srilanka
Posts: 2725
Good Answers: 5
#13

Re: Pressure Safety Valve Setting Point

04/30/2014 12:00 AM

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?.

__________________
pnaban
Register to Reply Score 1 for Off Topic
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#15
In reply to #13

Re: Pressure Safety Valve Setting Point

04/30/2014 1:37 AM

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.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Power-User

Join Date: Sep 2007
Location: I am located in Mumbai,India.
Posts: 126
Good Answers: 2
#14

Re: Pressure Safety Valve Setting Point

04/30/2014 12:05 AM

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.

__________________
Rajesh
Register to Reply Score 1 for Good Answer
Associate

Join Date: Aug 2010
Posts: 42
#16

Re: Pressure Safety Valve Setting Point

04/30/2014 3:57 AM

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.

Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 31525
Good Answers: 833
#18
In reply to #16

Re: Pressure Safety Valve Setting Point

04/30/2014 9:01 AM

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.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
2
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#19

Re: Pressure Safety Valve Setting Point

04/30/2014 11:15 PM

There are a lot of great points you need to carefully consider with the previous responses. However, I will answer "MAYBE" and not "NO" as others have advised.

First question is whether the existing equipment and system can safely handle the higher setpoint?

Second, does the safety valve have an adjustable spring, and do you have the manufacturer's instruction manual for adjusting the spring?

Third, do you have the capability to remove the valve from service and put it on a calibrated test apparatus to accurately test and measure the new setpoint. Is the technician trained to adjust, test, verify the new setpoint as the spring is adjusted?

Fourth, once the setpoint is adjusted, does the technician have the authority from ASME or whatever to place a new data plate on the valve stating the new relieving pressure and new capacity of the safety valve?

In theory, resetting a pressure safety valve is simple. The devil is in the details of doing it safely. Otherwise, it is no longer a safety valve. It becomes a "pop" valve, and no one knows how or when it goes POP!

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply Good Answer (Score 2)
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 791
#20
In reply to #19

Re: Pressure Safety Valve Setting Point

04/30/2014 11:23 PM

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 vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#21
In reply to #20

Re: Pressure Safety Valve Setting Point

04/30/2014 11:30 PM

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.

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply
Guru

Join Date: Oct 2008
Posts: 42369
Good Answers: 1683
#22
In reply to #21

Re: Pressure Safety Valve Setting Point

04/30/2014 11:36 PM

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.

Register to Reply
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#23
In reply to #22

Re: Pressure Safety Valve Setting Point

04/30/2014 11:41 PM

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

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 791
#24
In reply to #21

Re: Pressure Safety Valve Setting Point

04/30/2014 11:49 PM

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.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Jul 2007
Location: Commissariat de Police, Nouvions, occupied France, 1942.
Posts: 2599
Good Answers: 76
#25

Re: Pressure Safety Valve Setting Point

05/06/2014 3:57 AM

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?

__________________
Good moaning!
Register to Reply
Register to Reply 28 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Crabtree (1); IdeaSmith (2); Kevin LaPaire (1); lyn (3); ozzb (1); pnaban (1); PWSlack (2); redfred (2); Ried (3); rsalaskar (2); SHOCKHISCAN (1); subbharao (1); suvarna_mendu (1); Tornado (4); Wal (2); WJMFIRE (1)

Previous in Forum: Help! Paidar Chair Pump   Next in Forum: HDPE Covered Lagoons for Biogas Capturing

Advertisement