Safety & Relief Valve

There is no real difference in the first two terms. They both limit the pressure upstream of the valve.

The third maintains a set pressure downstream of the valve. So it's not the same thing as the first two.

please check a thread a few days back on exactly the same subject from your company, from your city.

Neither you google and it is obvious you do not discuss with your colleagues before running to computer and posting on forums.

Don't you share amongst yourselves or you find this forum only for time killing purpose.

I don't know the circumstances but i sincerely feel this type of environment do not signify a good organisational culture.

I am blunt, but I hope you will understand and try to improve the culture around you. Be a change agent.

Choose this link. The same question was just asked the other day.

Hi Sanjay:

I don't see any reason why someone could not start a new thread on a subject which has been mentioned before - after all we don't all follow forum discussions all the time and could easily miss some where they could have made some good contributions.

Pressure safety valves and Pressure relief valve are essentially the same type of valve. A Safety Valve has a connotation that it is used more where an overpressure could cause serious harm and damage, such as in Steam Safety valves on Boilers. A relief valve can be used in low pressure water systems where it is convenient to ensure that pressure does not exceed a setting as it causes some discomfort or minor damage to equipment. A Safety relief valve also opens fully when setpoint is reached whereas some relief valves (other terminology is a Pressure Sustaining Valve), modulate and only open far enough to maintain the setpoint at its desired setting.

A Pressure Control valve is a general terminology for a valve which controls pressure ie either upstream of the valve (Pressure Relief valve) or downstream of the valve (Pressure Reducing valve).

I trust this casts some more light on the subject

Dear SANJAY VAIDHYA

The difference between SAFETY VALVE and RELIEF VALVE

Relief valve will shut as soon as the working pressure is reached, since it works on lever principle since the MOMENTS of working pressure and the pressure due to dead weight is balanced.

SAFETY VALVE, will vent out as soon as the set pressure is reached but will shut down well below the working pressure which will be less than the SET PRESSURE to the tune of 0.5% to 1.2 % some times even 2.0% to 2.75% and this margin of difference between the set pressure and closing pressure is known as BLOW DOWN of the SAFETY VALVE.

Further Relief Valve is referred for the fluid flow system and incompressible fluid flow system

Also refer the link in CR4

http://cr4.globalspec.com/thread/32517/Pressue-Safety-Valves-vs-Pressure-Relief-Valves.

Thanks,

DHAYANANDHAN.S,