4 replies to this topic

[jonikxx]

I am starting out in work connected with marine applications and if I can get information it will save my job. I have been asked to find out:
1. Discharge pipe and calculation of the built up back pressure.
2. Stationary forces at the safety valve.
3. The best position /orientation for the discharge pipes.

The valve details are as follows:
Service: 16 BARG steam header pressure relief valve
Nozzle: FULL
Size: Inlet - 6" / Outlet - 8"
Design Type: Conventional
Fluid: Steam
State: Vapour
Density: 8.23 kgs/mtr3
Operating Pressure: 16 Bar
Set Point: 18Bar
Operating Temperature: 217deg C
Built up back pressure value: Variable/ 1BARG
Required Capacity: 64,200 kg/hr.

Any info as to calculations required would be appreciated very much.

[JoeWong]

1. Discharge pipe and calculation of the built up back pressure.
2. Stationary forces at the safety valve.
3. The best position /orientation for the discharge pipes.

Have you tried these standards

i) API Std 520 (2007) for question 1
ii) API RP 521 Pt.II for question 2 & 3

[pleckner]

Joe has somethings mixed up and we'll forgive him for this...late night Joe?

i) API Std 520 (2007) for question 1

520 is still API RP 520, January 2000. Joe might have been thinking API Standard 521, January 2007 for this question.

There is information in API RP 520 that will help you. I would also look at API Standard 521 for additional information on this calculation.

ii) API RP 521 Pt.II for question 2 & 3

This should be API RP 520 Part II, Installation for questions 2 & 3.

[JoeWong]

Phil,
Wow ! Sharp eye ! Thanks.

I am in Europe now. So i responded in day time. Infact i have responded this post in rush. I apologize for my mistake.

Lesson learnt. Never do thing in rush and over-confidence.

To be exact...

i) API Std 521 - ISO 23251 - Ed 5 - Jan 2007 Pressure-relieving and Depressuring Systems for question 1.
ii) API RP 520 PII - Ed 5 Aug 2003 Sizing, Selection & Installation of Pressure-Relieving Devices in Refinery for question 2 & 3

[jonikxx]

Joe has somethings mixed up and we'll forgive him for this...late night Joe?

i) API Std 520 (2007) for question 1

520 is still API RP 520, January 2000. Joe might have been thinking API Standard 521, January 2007 for this question.

There is information in API RP 520 that will help you. I would also look at API Standard 521 for additional information on this calculation.

ii) API RP 521 Pt.II for question 2 & 3

This should be API RP 520 Part II, Installation for questions 2 & 3.

Thanks guys. Appreciate your help.